Synthesis and Characterization of Three-dimensional (3D) Flowerlike CuO by a Simple Chemical

Synthesis and characterization of carbon-doped titania as an artificial solar light sensitive photocatalystYuanzhi Lia,b,Doo-Sun Hwang a ,Nam Hee Lee a ,Sun-Jae Kima,*aSejong Advanced Institute of Nano Technologies,#98Gunja-Dong,Gwangjin-Gu,Sejong University,Seoul 143-747,KoreabDepartment of Chemistry,China Three Gorges University,8College road,Yichang,Hubei 4430002,PR ChinaReceived 1December 2004;in final form 4January 2005AbstractThe carbon-doped titania with high surface area was prepared by temperature-programmed carbonization of K-contained ana-tase titania under a flow of cyclohexane.This carbon-doped titania has much better photocatalytic activity for gas-phase photo-oxi-dation of benzene under irradiation of artificial solar light than pure titania.The visible light photocatalytic activity is ascribed to the presence of oxygen vacancy states because of the formation of Ti 3+species between the valence and the conduction bands in the TiO 2band structure.The co-existence of K and carbonaceous species together stabilize Ti 3+species and the oxygen vacancy state in the as-synthesized carbon-doped titania.Ó2005Elsevier B.V.All rights reserved.Titania is well known as a cheap,nontoxic,efficient photocatalyst for the detoxication of air and water pol-lutants.However,it is activated only under UV light irradiation because of its large band gap (3.2eV).Be-cause only 3%of the solar spectrum has wavelengths shorter than 400nm,it is very important and challeng-ing to develop efficient visible light sensitive photocata-lysts by the modification of titania.Several attempts have been made to narrow the band gap energy by tran-sition metal doping [1–3],but these metal-doped photo-catalysts have been shown to suffer from thermal instability,and metal centers act as electron traps,which reduce the photocatalytic efficiency.Recently,the mod-ification of titania by nonmetals (e.g.S,N,C,B)receive much attention as the incorporation of these nonmetals into titania could efficiently extend photo-response from UV (ultra-violet)to visible regions [4–10].Here,we re-port a method of synthesizing carbon-doped titania with a high surface area.It was found that the as-synthesizedcarbon-doped titania showed much better photocata-lytic activity for photo-oxidation of benzene under irra-diation of artificial solar light than undoped titania.The as-synthesized carbon-doped titania was pre-pared by the following procedure.0.10mol TiCl 4(98%TiCl 4,Aldrich)were added slowly drop wise into 200ml portions of distilled water in an ice bath.The ob-tained transparent TiOCl 2aqueous solution was heated rapidly to 100°C,and then kept at this temperature for 10min for hydrolysis of TiOCl 2.The precipitates formed in the solution were filtered,neutralized to pH 8.0by 0.1mol/l KOH aqueous solution,washed thor-oughly with distilled water,and then finally dried at 150°C in air for 24h.The carbon-doped titania was prepared by temperature-programmed carbonization (TPC)of anatase titania in a flow of Ar saturated by cyclohexane at 20°C in a quartz tube reactor.The load-ing of titania was 2g,and the flowing rate of Ar was 500ml (STP)/min.The sample was heated to the car-bonization temperatures between 450and 500°C at a rate of 0.5°C/min and kept at the temperature for 2h.After rapidly cooling to room temperature in a flow of Ar,a grayish sample of titania was obtained.0009-2614/$-see front matter Ó2005Elsevier B.V.All rights reserved.doi:10.1016/j.cplett.2005.01.062*Corresponding author.Fax:+82234083664.E-mail address:sjkim1@sejong.ac.kr (S.-J.Kim)./locate/cplettChemical Physics Letters 404(2005)25–29The crystalline phase of samples was determined by XRD.Before TPC,the obtained titania prepared by hydrolysis of TiOCl2aqueous solution had pure anatase structure.The crystalline phase of anatase sample was almost unchanged even after TPC except for the forma-tion of a small amount of rutile phase infinally obtained carbon-doped pared to pure titania pre-pared by same procedure but replacing cyclohexane sat-urated Ar by air,the carbon doped titania has lower rutile content,indicating that TPC inhibited the trans-formation of anatase to rutile phase.The average crystal size of as-synthesized carbon-doped titania is estimated by the Scherrer formula:L=0.89k/b cos h to be7.6nm. BET surface area measurement showed that the as-syn-thesized carbon-doped titania by TPC at475°C had as high as204m2/g specific surface area,which is impor-tant for improving photocatalytic activity.But the car-bon-doped titania prepared by reported carbon doping method usually had a lower specific surface area and larger crystal size[11,12].Fig.1gives the UV–Vis diffusive reflectance absorp-tion spectra of the pure titania and carbon-doped titania pared to that of the carbon-doped titania, the absorption edge near400nm of the pure titania has a red-shift of20nm,which might be contributed by the higher content of rutile in pure titania than in carbon-doped titania,as rutile has a narrower band gap (3.0eV)than anatase(3.2eV).The as-synthesized pure titania almost has no absorption above400nm.How-ever,the doping of carbon results in obvious absorption of titania up to700nm.This absorption feature suggests that these carbon-doped titania can be activated by visible light.The photocatalytic activity of as-synthesized titania samples for the gas-phase oxidation of benzene was tested on a home-made re-circulating gas-phase photo-reactor with a quartz window,which was connected to the ppbRAE meter(RAE system Inc.)to re-circulate a mixture of benzene and ambient air without additional drying and measure concentration of the volatile organic compounds(VOCs).Artificial solar light with full spec-trum(32W VITA LITE lamp)was used as irradiation source.First,0.7000g titania powder was put into the reactor,then a known amount of benzene was injected in the system under dark.After the adsorption of benzene on titania reached to adsorption equilibrium,artificial solar light was turn on.Fig.2shows the amounts of total volatile organic compounds(VOCs)with the artificial so-lar light irradiation time.Morawski and co-workers[13] prepared carbon-modified titania by heating at the high temperatures of titanium dioxide in an atmosphere of gaseous n-hexane.They found that carbon-modified titania had catalytic photoactivity slightly lower than that of TiO2without carbon deposition.In our experi-ment of preparing anatase TiO2by hydrolysis of TiOCl2 solution,the precipitate was neutralized to pH8.0by 0.1mol/l KOH aqueous solution.When we did not use KOH solution to neutralize the titania precipitate and just washed thoroughly the titania precipitate with dis-tilled water.Then,we use this titania without neutraliza-tion by KOH solution to prepare the carbon-doped titania by TPC.It was found that this carbon-doped titania has almost similar photocatalytic activity for the gas-phase photo-oxidation of benzene to the un-doped titania prepared by the same procedure but replacing cyclohexane saturated Ar by air.This result is similar to the result reported by Morawski et al.How-ever,the as-synthesized carbon-doped titania,which was prepared by TPC of anatase titania with neutralization by KOH solution,have much better photoactivity for the gas-phase photo-oxidation of benzene than the un-doped titania as well as Degussa P25titania,a bench-marking photocatalyst.This result shows that the neutralization of titania by KOH solution plays very important role in the photocatlytic activity of thefinally obtained carbon-doped titania,and doping a proper26Y.Li et al./Chemical Physics Letters404(2005)25–29amount of carbon into the KOH neutralized titania by our method leads to the obvious enhancement of its photoactivity.Our experiment shows that thefinal carbonization temperature has an important effect on the photoactiv-ity,and the optimum carbonization temperature is be-tween475and500°C.The photocatalytic activity of the as-synthesized carbon-doped titania is unchanged after several successive cycles of photocatalytic tests un-der artificial light irradiation,indicating the stability of the catalysts after photolysis.Asahi et al.[5]made a theoretical calculation of the densities of states(DOSs)of the substitutional doping of C,N,F,P,or S for O in the anatase TiO2crystal by the full-potential linearized augmented plane wave in the framework of the local density approximation (LDA).They thought that the substitutional doping of N or S was the most effective because its p states contrib-ute to the band gap narrowing by mixing with O2p states,but the states introduced by C and P are too deep in the gap to satisfy one of the requirements for visible light sensitive photocatalyst.However,previous works [11,12,14]and our experiment show that the carbon-doped titania has visible light photocatalytic activity. Therefore,we must try tofind the reason why as-synthe-sized carbon-doped titania has visible light photocata-lytic activity.To investigate the carbon states in the photocatalyst, C1s core levels were measured by X-ray photoemission spectroscopy(XPS),as shown in Fig.3a.There are two XPS peaks at284.6,288.2eV for the as-synthesized carbon-doped titania,but it was confirmed that there was only one peak at284.6eV for pure titania even though it is not shown here.Obviously the peak at 284.6eV arises from adventitious elemental carbon. Hashimoto and co-workers[11]prepared carbon-doped titania by oxidizing TiC,and observed C1s XPS peak with much lower binding energy(281.8eV).They as-signed this C1s XPS peak to Ti–C bond in carbon-doped anatase titania by substituting some of the lattice oxygen atom by carbon.Khan et al.[12]synthesized carbon-modified rutile titania by controlledflame pyrolysis of Ti metal,and thought that the carbon substituted for some of the lattice oxygen atoms.However,Sakthivel and Kisch[14]prepared carbon-modified titania by hydrolysis of titanium tetrachloride with tetrabutylam-monium hydroxide followed by calcinations at400°C, and observed the two kinds of carbonate species with binding energies of287.5and288.5eV.These resultssuggest that the preparation method plays an important role in determining the carbon oxidation state in car-bon-modified titania:both substitution of the lattice oxygen in the titania and the formation of carbonate species in titania lead to the narrowing of the band gap infinal obtained carbon-doped titania.Our result is similar to that of Sakthivel and Kisch,but the carbon-doped titania prepared by our method only has one peak nearby at288.2eV,indicating the presence of only one kind of carbonate species.Therefore,our result does not contradict the theoretical expectation of Asahi et al.because the carbon exists in form of carbonate, not by substituting the oxygen of the anatase in the as-synthesized carbon-doped titania.The sensitivity ofY.Li et al./Chemical Physics Letters404(2005)25–2927the as-synthesized carbon-doped titania to visible light maybe arises from other reason.The surface carbon concentration in our sample was estimated by XPS to be7.3%.The XPS spectral of Ti2p region were also shown(Fig.3b).The XPS spectra of Ti2p3/2in the car-bon-doped titania can befitted as one peak at457.8eV. Compared to the binding energy of Ti4+in pure anatase titania(458.6eV),there is a red-shift of0.8eV for the carbon-doped titania,which suggests that Ti3+species was formed in the carbon-doped titania[15].In our experiment of preparing anatase TiO2,the precipitate was neutralized to pH8.0by0.1mol/l KOH aqueous solution.K was also detected by XPS in thefinally ob-tained carbon-doped titania prepared from this KOH neutralized titania.The XPS spectral of K2p region were also shown(Fig.3c).The XPS spectra of K2p3/2in the carbon-doped titania can befitted as one peak at 292.5eV,which could be assigned to K+.The surface K concentration in our sample was estimated by XPS to be13.3%.Fig.4shows EPR spectra of as-synthesized doped titania,recorded at77K and ambient temperature un-der dark.The XPS results show the presence of Ti3+ in the as-synthesized carbon-doped titania.It can be seen from Fig.4that Ti3+is also detected by EPR at low temperature(77K).Moreover,there are observed two kinds of Ti3+in the as-synthesized carbon-doped titania.The signal at g^=1.9709,g i=1.9482is assigned to surface Ti3+[16,17],and the signal at g=1.9190is as-signed to vacancy-stabilized Ti3+in the lattice sites or similar center in the subsurface layer of titania[18,19]. At ambient temperature,the Ti3+EPR signal disap-pears,but the strong symmetric signal at g=2.0055still exists,and no EPR signal was detected for pure anatase titania.Moreover,our experiment showed that the used carbon-doped titania still had a strong EPR signal at g=2.0055after experienced photocatalytic test.Serwicka[20]observed a broad signal assigned to Ti3+ ions at g=1.96and a sharp signal at g=2.003on the vacuum-reduced TiO2at673–773K.They attributed the latter signal to a bulk defect,probably an electron trapped on an oxygen vacancy.Nakamura et al.[21]re-ported that the symmetrical and sharp EPR signal at g=2.004detected on plasma-treated TiO2arose from the electron trapped on the oxygen vacancy.The pres-ence of Ti3+in the as-synthesized carbon-doped titania implies that there must be some change for oxygen spe-cies localized near Ti3+in the carbon-doped titania to satisfy the requirement of charge equilibrium,which is further confirmed by the EPR proof of the existence of vacancy-stabilized Ti3+in the as-synthesized carbon doped bined with the reported assignment for the EPR signal,the signal at g=2.0055newly ob-served here for the as-synthesized carbon-doped titania can be assigned to the electron trapped on the oxygen vacancy.It was reported that reducing TiO2introduces localized oxygen vacancy states located at0.75–1.18eV below the conduction band edge of TiO2[22],which re-sults in sensitivity of the reduced TiO x photocatalyst to visible light.So,for titania containing localized oxygen vacancy,the band gap between valence band and local-ized oxygen vacancy state is 2.45–2.02eV.Our UV experiments showed that the carbon-doped titania has an obvious absorption up to700nm(mainly in the re-gion of450–610nm(2.74–2.02eV))as shown in Fig.1, which further confirms that localized oxygen vacancy states actually exist in the as-synthesized carbon-doped titania and the existence of localized oxygen vacancy states results in the sensitivity of the as-synthesized car-bon-doped titania photocatalyst to visible light.Based on our results of UV,XPS and EPR,it is concluded that the presence of Ti3+species produced in the process of carbon doping of the K-contained titania leads to the formation of oxygen vacancy state(O t.Ti3+)in the as-synthesized carbon-doped titania between the valence and the conduction bands in the TiO2band structure, which results in the sensitivity of the as-synthesized car-bon-doped titania to visible light and its high photocat-alytic activity under irradiation of artificial solar light.It was proved by our photocatalytic experiment that the oxygen vacancy state in the as-synthesized carbon-doped titania had good stability because its photocata-lytic activity was unchanged after several successive cycles of photocatalytic test under artificial light irradiation.We think that the co-existence of K and carbonaceous species together stabilize Ti3+species and the oxygen vacancy state in the as-synthesized carbon-doped titania.In summary,the carbon-doped titania with high sur-face area and good crystallinity was prepared by temper-ature-programmed carbonization of nano anatase titania withfinal carbonization temperature of475°C under aflow of cyclohexane.This carbon-doped titania28Y.Li et al./Chemical Physics Letters404(2005)25–29showed an obvious absorption of titania up to700nm, and had much better photocatalytic activity for gas-phase photo-oxidation of benzene under irradiation of artificial solar light than pure titania.The visible light photocatalytic activity is ascribed to the presence of oxy-gen vacancy state because of the formation of Ti3+spe-cies in the as-synthesized carbon-doped titania between the valence and the conduction bands in the TiO2band structure,which results in sensitivity of the as-synthe-sized carbon-doped titania to the visible light. AcknowledgmentsThe authors are grateful to Basic Research Program of Korea Science and Engineering Foundation(Grant No.R01-2002-000-00338)forfinancial support. References[1]H.Kisch,L.Zang, nge,W.F.Maier, C.Antonius, D.Meissner,Angew.Chem.,Int.Ed.37(1998)3034.[2]W.Macyk,H.Kisch,Chem.Eur.J.7(2001)1862;C.Wang,D.W.Bahnemann,J.K.Dohrmann,mun.16(2000)1539.[3]H.Yamashita,M.Honda,M.Harada,Y.Ichihashi,M.Anpo,T.Hirao,N.Itoh,N.Iwamoto,J.Phys.Chem.B102(1998) 10707.[4]T.Umebayashi,T.Yamaki,H.Itoh,K.Asai,Appl.Phys.Lett.81(3)(2002)454.[5]R.Asahi,T.Ohwaki,K.Aoki,Y.Taga,Science293(2001)269.[6]C.Burda,Y.Lou,X.Chen,A.C.S.Samia,J.Stout,J.L.Gole,Nano Lett.3(8)(2003)1049.[7]H.Irie,Y.Watanabe,K.Hashimoto,J.Phys.Chem.B107(2003)5483.[8]J.L.Gole,J.D.Stout,C.Burda,Y.Lou,X.Chen,J.Phys.Chem.B108(2004)1230.[9]T.Lindgren,J.M.Mwabora,E.Avendano,J.Jonsson,A.Hoel,C.Granqvist,S.Lindquist,J.Phys.Chem.B107(2003)5709.[10]W.Zhao,W.Ma,C.Chen,J.Zhao,Z.Shuai,J.Am.Chem.Soc.126(2004)4782.[11]H.Irie,Y.Watanabe,K.Hashimoto,Chem.Lett.32(8)(2003)772.[12]S.U.M.Khan,M.Al-shahry,W.B.Ingler Jr.,Science297(2002)2243.[13]M.Janus,B.Tryba,M.Inagaki,A.W.Morawski,Appl.Catal.B52(2004)61.[14]S.Sakthivel,H.Kisch,Angew.Chem.,Int.Ed.42(2003)4908.[15]X.Y.Du,Y.Wang,Y.Y.Mu,L.L.Gui,P.Wang,Y.Q.Tang,Chem.Mater.14(2002)3953.[16]Y.Z.Li,Y.N.Fan,H.P.Yang,B.L.Xu,L.Y.Feng,M.F.Yang,Y.Chen,Chem.Phys.Lett.372(2003)160.[17]L.Bonneviot,G.L.Haller,J.Catal.113(1988)96.[18]T.Huizinga,R.Prins,J.Phys.Chem.85(1981)2156.[19]S.A.Fairhurst, A.D.Inglis,Y.Le Page,J.R.Morton,K.F.Preston,Chem.Phys.Lett.95(1983)444.[20]E.Serwicka,Colloid.Surf.13(1985)287.[21]I.Nakamura,N.Negishi,S.Kutsuna,T.Ihara,S.Sugihara,K.Takeuchi,J.Mol.Catal.A161(2000)205.[22]D.C.Cronemeyer,Phys.Rev.113(1959)1222.Y.Li et al./Chemical Physics Letters404(2005)25–2929。

化工进展 2016年第35卷·846·of Mn，Fe，Co，Ni，Cu and Zn：relationship to the 3-methyl analogs[J].Inorg. Chim. Acta，2000，300-302：1082-1089.[36] GHASSEMZADEH M，FALLAHNEDJAD L，HERA VI M M，et al.Synthesis，characterization and crystal structure of new silver(I) andpalladium(Ⅱ) complexes containing 1,2,4-triazole moieties[J]. Polyhedron，2008，27（6）：1655-1664.[37] ROBIN J Blagg R J，L´Opez-G´Omez M G，CHARMANT J P H，et al. The oxidative conversion of the N,S-bridged complexes[{RhLL’(μ-X)}2] to [(RhLL’)3(μ-X)2]+ (X = mt or taz)：acomparison with the oxidation of N,N-bridged analogues[J]. Dalton.Trans.，2011，40（43）：11497-11510.[38] CASTIN E A，GARCI´A-SANTOS I，DEHNEN S，et al. Synthesis，characterization and DFT calculations of a novel hexanuclear silver(I)cluster-complex containing 4-ethyl-5-pyridin-2-yl-2,4-dihydro-[1,2,4]triazol-3-thione as a result from the cyclization of 2-pyridinformamideN-4-ethylthiosemicarbazone [J]. Polyhedron，2006. 25（18）：3653-3660.[39] BHARTI A，BHARTY M K，KASHY AP S，et al. Hg(Ⅱ) complexesof 4-phenyl-5-(3-pyridyl)-1,2,4-triazole-3-thione and 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione and a Ni(Ⅱ) complex of 5-(thiophen-2-yl)-1,3,4-oxadiazole -2-thione：synthesis and X-ray structural studies[J].Polyhedron，2013，50（1）：582-591.[40] YU H X，MA J F，XU G H，et al. Syntheses and crystal structures offour new organotin complexes with Schiff bases containing triazole[J].J. Organomet. Chem.，2006，691（16）：3531-3539.[41] PATIL S A，MANJUNATHA M，KULKARNI A D，et al. Synthesis，characterization，fluorescence and biological studies of Mn(Ⅱ)，Fe(Ⅲ)and Zn(Ⅱ) complexes of Schiff bases derived from Isatin and 3-substituted-4-amino-5-mercapto-1,2,4-triazoles[J]. Complex. Met.，2014，1：128-137.[42] CAMMI R，LANFRANCHI M，MARCHIO L，et al. Synthesis andmolecular structure of the dihydrobis (thioxotriazolinyl) boratocomplexes of zinc(Ⅱ)，bismuth(Ⅲ)，and nickel(Ⅱ). M…H-Binteraction studied by Ab initio calculations[J]. Inorg. Chem.，2003，42（5）：1769-1778.[43] CHU W J，YAO H C，MA H C，et al. Syntheses，structures，andcharacterizations of two coordination polymers assembled from zinc(Ⅱ) salts with 1,2-bis[3-(1,2,4-triazolyl)-4-amino-5-carboxylmethylthio]ethane[J]. J. Coord. Chem.，2010，63（21）：3734-3742.[44] CHU W J，YAO H C，FAN Y T，et al. Anion exchange inducedtunable catalysis properties of an uncommon butterfly-liketetranuclear copper(Ⅱ) cluster and magnetic characterization[J].Dalton. Trans.，2011，40（11）：2555-2561.[45] CHU W J，HE Y，ZHAO Q H，et al. Two 3D network complexes ofY(Ⅲ) and Ce(Ⅲ) with 2-fold interpenetration and reversibledesorption-adsorption behavior of lattice water[J]. Journal of SolidState Chemistry，2010，183（10）：2298-2304.[46] CHU W J，HOU X W，ZHAO Q H，et al. Four novel lanthanide(Ⅲ)coordination polymers with 3D network structures containing 2-foldinterpenetration[J]. Inorg. Chem. Commun.，2010，13（1）：22-25. [47] AIN Q，PANDEY S K，PANDEY O P，et al. Synthesis，spectroscopic，thermal and antimicrobial studies of neodymium(Ⅲ) and samarium(Ⅲ) complexes derived from tetradentate ligands containing N and Sdonor atoms[J]. Spectrochim. Acta，Part A，2015，140：27-34.[48] BAHEMMAT S，GHASSEMZADEH M，AFSHARPOUR M，et al.Synthesis，characterization and crystal structure of a Pd(Ⅱ) complexcontaining a new bis-1,2,4-triazole ligand：a new precursor for thepreparation of Pd(0) nanoparticles[J]. Polyhedron，2015，89：196-202. [49] ZHANG R F，WANG Q F，LI Q L，et al. Syntheses andcharacterization of triorganotin(IV) complexes of Schiff base derivefrom 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol and 5-amino-1,3,4-thiadiazole-2-thiol with p-phthalaldehyde[J]. Inorg. Chim. Acta，2009，362（8）：2762-2769.[50] BHAT K S，POOJARY B，PRASAD D J，et al. Synthesis andantitumor activity studies of some new fused 1,2,4-triazole derivativescarrying 2,4-dichloro-5-fluorophenyl moiety[J]. Eur. J. Med. Chem.，2009，44：5066-5070.2016年第35卷第3期CHEMICAL INDUSTRY AND ENGINEERING PROGRESS ·847·化工进展基于壳聚糖的分子印迹聚合物的制备和应用许龙1，黄运安1，朱秋劲1，2，叶春1（1贵州大学酿酒与食品工程学院，贵州贵阳550025；2贵州大学食品科学工程研究中心，贵州贵阳550025）摘要：壳聚糖具有良好的生物相容性和独特的分子结构，基于其制备的分子印迹聚合物因亲和性和选择性高、应用范围广等特点引起了广泛的关注。

第 20 卷 第 1 期湖南理工学院学报（自然科学版）V ol.20 No.12007 年 3 月Jour n al of Hu n a n Ins titu te of Sc ien ce a nd Tech n o lo gy (N atu ral Sc ien ce s)Mar .2007苯甲叉基丙二腈中间体合成黄酮类化合物及表征杨 涛，周从山 ，谢 芳（湖南理工学院 化学化工系，湖南 岳阳 414000）摘 要：本文采用苯甲叉基丙二腈作为中间体，与间苯二酚在无水 ZnCl 2 和 HCl 气体的催化作用下制得亚胺盐，再水 解,脱羧,分离得到产物,通过液相色谱、紫外、红外等手段对中间产物和最终产物进行分析鉴定，确定最终产物是 7-羟基二 氢黄酮。

关键词：苯甲叉基丙二腈；黄酮；间苯二酚；7-羟基二氢黄酮中图分类号：O623.76文献标识码：A文章编号：1672-5298(2007)01-0080-03Synthesis using Phenylmethylenepropanedinitriles as intermediate and characterization of flavonoids compoundY ANG Tao, ZHOU Cong-shan, XIE Fang(Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Y ueyang 414000, C hina)Abstract: Two imino-compounds were obtained by the catalysis of ZnCl 2 and HCl using benzylidenemalononitrile and resorcinol as intermediate, which were directly hydrolyzed and decarboxylated without apart. The product was abstracted. All the intermediate and final product were analyzed and characterized by liquid chromatography, ultraviolet Spectrophotometer, infrared Spectrophotometer, we make sure that the final product is 7-hydroxy-2,3-dihydro-2-flaconoid.Key words: benzylidenemalononitrile ； falconoid ；resorcinol ；7-hydroxy-2,3-dihydro-2-flaconoid黄酮类化合物是一类广泛存在于自然界的天然有机化合物。

Synthesis and Characterization ofMagnesium -S aponite by H ydrotherm al W ayΞYAO Ming 1,2,　WAN G Kai 2xiong 1,　L IU Zi 2yang 2,　SHI Wen 2yan 1,　SUN Hong 2jie 2(1.Department of Environmental Engineering ,Zhejiang University ,Hangzhou 310029,China ;2.Department of Chemistry ,Zhejiang University ,Hangzhou 310027,China )Abstract :According to an optimized hydrothermal synthesis method ,trioctahedral smectite (mag 2nesium 2saponite )with good long range order was synthesized within 2h at 473K.The reflection peaks of XRD pattern confirmed the trioctahedral layer structure of the product.TEM results were in good agreement with that of saponite synthesized hydrothermally at higher reaction tempera 2tures.According to the determinations of the products synthesized under different reaction temper 2atures (423K ,473K ,523K ,573K ),473K was found to be a temperature threshold within short reaction time in the synthesis of sapontie having high long range order.As to the adsorption of or 2ganic cationic dye (MB ),the capability of saponites with different layer charges exhibited similar capability.However ,the mechanism of this kind of adsorption in the remediation of ionic type pol 2lutants involved flocculation and ion pared with natural montmorillonite ,the syn 2thetic saponite showed higher adsorption capability and affinity to ionic dye.K eyw ords :hydrothermal synthesis ;saponite ;montmorillonite ;XRD ;TEM ;dyeadsorption ;aque 2ous pollution remediation C LC number :O611.4Document code :AP aper number :100521511(2004)0520457205镁皂石的水热合成与表征研究姚　铭1,2,王凯雄1,刘子阳2,施文彦1,孙红杰2(1.浙江大学环境工程系,浙江杭州　310029;2.浙江大学化学系,浙江杭州　310027)摘要:采用优化的水热合成法,在473K 反应2h 合成了具有优良长程有序性的2∶1型三八面体蒙皂石(皂石)。

第 29 卷第 1 期分析测试技术与仪器Volume 29 Number 1 2023年3月ANALYSIS AND TESTING TECHNOLOGY AND INSTRUMENTS Mar. 2023浙江省大型科研仪器开放共享平台—质谱专栏(83 ~ 92)质谱在金属有机框架材料结构与应用表征上的研究进展陈银娟1 ，丁传凡2 ，卢星宇1（1. 西湖大学分子科学公共实验平台，浙江省功能分子精准合成重点实验室，浙江杭州　310024；2. 宁波大学材料科学与化学工程学院，浙江省先进质谱技术与分子检测重点实验室，质谱技术与应用研究院，浙江宁波　315211）摘要：金属有机框架材料（metal organic frameworks, MOFs）是指由金属离子或金属团簇与有机配体形成的一类多孔材料，具有比表面积大、气孔率高和热稳定性能优良等特点，在能源、环境、生物医药等领域应用广泛. 质谱可有效测定各种金属元素的成分和含量，精准分析化合物的组成和结构，其灵敏度高、分析速度快，是表征MOFs 的有效技术之一. 在质谱技术中，样品的离子化是进行质谱分析检测的重要前提，因此从常见离子源的原理与特点出发，对采用质谱技术表征MOFs的常用离子源种类、样品要求及产生的离子类型进行总结，并进一步对质谱在MOFs定性、反应监测及应用分析等方面的研究进展进行综述.关键词：质谱；金属有机框架材料；电喷雾电离；大气压化学电离；基质辅助激光脱附电离中图分类号：O657.63 文献标志码：A 文章编号：1006-3757（2023）01-0083-10DOI：10.16495/j.1006-3757.2023.01.013Progress of Mass Spectrometry to Metal Organic FrameworksCharacterization on Structure and ApplicationsCHEN Yinjuan1， DING Chuanfan2， LU Xingyu1（1. Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, Instrumentation and Service Center for Molecular Sciences, Westlake University, Hangzhou 310024, China；2. Institute of Mass Spectrometry Technology and Application, Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry Technology and Molecular Detection, School of Materials Science and Chemical Engineering,Ningbo University, Ningbo 315211, Zhejiang China）Abstract：Metal-organic frameworks (MOFs) are a class of porous materials formed with metal ions or oligonuclear metallic complexes and organic ligands. MOFs have a wide range of applications in energy, environment and biomedicine areas due to their high specific surface area, high porosity, excellent thermal stability, etc. Mass spectrometry (MS) can efficiently identify specific metal species and precisely characterize compound composition, and its high sensitivity and fast analysis speed make it one of the effective methods for characterizing MOFs. In mass spectrometry, ionization of MOFs is an important prerequisite for mass spectrometric analysis and detection. Starting from the principles and characteristics of common ion sources, ion source, sample requirement and types of ions generated for characterizing MOFs by MS are summarized. Furthermore, the associated qualitative analysis, reaction monitoring and applications research of MOFs by MS are reviewed.收稿日期：2023−01−31；　修订日期：2023−03−03.作者简介：陈银娟（1986−），女，博士，研究方向：色谱/质谱方法学研究，E-mail：.Key words：MS；MOFs；electrospray ionization；atmospheric pressure chemical ionization；matrix-assisted laser desorption/ionization金属有机框架材料（metal-oragnic frameworks, MOFs）是一类由金属离子或金属簇与有机配体形成的具有一维、二维或三维的配合物材料. MOFs 具有比表面积大、气孔率高和热稳定性能优良等特点，常用于催化、化学传感器、无机和有机成分的吸附，如有毒成分或离子吸附等，备受化学、环境和生物医药等领域科研人员的青睐[1-7]. 因MOFs的重要理论和应用价值，科学家们根据它的空间结构及化学组成的特点，发展了一系列用于表征其性质的方法，如X-射线衍射（X-ray diffraction, XRD）、核磁共振波谱（nuclear magnetic resonance spectroscopy, NMR）、X-射线光电子能谱（X-ray photoelectron spectroscopy, XPS）、X-射线吸收谱（X-ray absorption spectroscopy, XAS）、扫描电子显微镜（scanning elec-tron microscopy, SEM）、傅里叶变换红外光谱（four-ier transform infrared spectroscopy, FTIR）、透射电子显微镜（transmission electron microscopy, TEM）及质谱（mass spectrometry, MS）等用于此类化合物的结构定性与应用表征[8-14]. 近年来，由于质谱技术的飞速发展，它可以快速准确地分析气相、液相、固相样品中各种物质的种类（定性分析）及其含量（定量分析），质谱与色谱联用还能进行复杂混合物的高灵敏分析，尤其是高分辨质谱分析可有效进行元素分析，精准推断化合物组成，在MOFs表征上显示出特有的优势.由于质谱的检测对象是离子，离子源是质谱的关键部件之一，它是将分子或原子电离成离子，然后供后续质量分析器分析. 离子源不仅为质谱仪提供可分析的样品离子，而且其种类与质谱的应用密切相关. 目前常用的商业化离子源包括：电喷雾电离（electrospray ionization, ESI）[15-16]、大气压化学电离（atmospheric pressure chemical ionization, APCI）[17]、电子轰击电离（electron-impact ionization, EI）[18-19]、基质辅助激光脱附电离（matrix-assisted laser desorp-tion/ionization, MALDI）[20-21]及电感耦合等离子电离（inductively coupled plasma, ICP）[22]等.基于MOFs的研究热点和质谱的技术优势，本文从常见离子源的原理和特点出发，总结了质谱用于MOFs 分析时样品的要求及离子化特点，并基于此进一步介绍了质谱在MOFs分析及应用表征方面的研究进展.1　离子源概述自1886年气体放电离子源（gas discharge ionization）作为质谱仪的首个离子源出现至今，各种电离技术层出不穷[23-24]. 2004年，电喷雾脱附电离（desorption electrospray ionization, DESI）的发明更是推动直接质谱分析技术的发展和应用[25]. 张兴磊等[26]从离子化能量作用方式概述了直接质谱技术的发展，并对近年来出现的新型离子化技术和装置进行了系统总结. 离子源的种类与样品性质和质谱应用相关，表1列举了常见离子源电离的特点及应用领域.1.1　ESIESI是目前应用最广泛的离子源之一. 1984年，表 1 常见离子源电离特点及应用Table 1　Characteristics and applications of several common ion sources离子源分类离子类型应用领域文献火花离子源（spark source, SS）放电原子离子固体样品，痕量分析[27]辉光放电（glow discharge, GD）等离子体诱导原子离子痕量分析[28]诱导耦合等离子体（inductively coupled plasma,ICP）等离子体诱导原子离子同位素分析，痕量分析[22]电子轰击（electron-impact ionization, EI）电子诱导不稳定的分子离子小分子，GC-MS数据库比对[18]化学电离（chemical ionization, CI）电子诱导不稳定的分子离子GC-MS[29]大气压化学电离（atmospheric pressure chemical ionization, APCI）电子诱导稳定的分子离子小分子，非极性或弱极性，LC-MS[17]大气压光电离（atmospheric pressure photoionization, APPI）光稳定的分子离子LC-MS，极性化合物[30]84分析测试技术与仪器第 29 卷美国化学家John Fenn和日本科学家Yamashita将ESI用作质谱离子源产生样品离子，后来进一步改进用作液相色谱-质谱（LC-MS）仪的接口. ESI电离的基本过程如图1 [36-37]（a）所示：样品溶于极性可挥发性溶剂中，并以一定流速经过石英毛细管. 在毛细管尖端加高电压场，尖端会产生带电小液滴. 带电小液滴经氮气流扫吹及加热等辅助去溶剂化作用，产生化合物离子[15-16]. “残余电荷机理”（charge residue model）[38]及“离子蒸发机理”（ion evapora-tion model）[39]常用于解释ESI电离的过程，Keberle 等[40-42]认为ESI是一种在大气环境下发生的特殊的电化学过程.ESI的出现是质谱发展史上的一次重大飞跃.该离子源的特点包括：ESI在大气压条件下电离，是LC-MS的完美接口. 软电离，可以用于分析非共价复合物（non-covalent complexes）. 产生多电荷离子，应用到生物大分子领域. 也可以用于适合分析极性化合物[40]. 基于以上特点，ESI电离MOFs如产生加合分子离子峰（比如[M+H]+，[M+Na]+），样品应有一定极性，通常有机配体需具有质子化结合位点[11, 43].1.2　APCIAPCI是在大气压条件下电离气体样品的离子源，适合分析非极性和弱极性化合物，弥补了ESI 电离此类化合物的不足，是LC-MS和气相色谱-质谱（GC-MS）的常见接口. APCI离子源结构如图1（b）所示：在电晕针上加电流，电晕放电产生稳定的反应离子（例如N2+），流动相载带的样品溶液，在加热和高流速气流作用下发生气化，气体样品分子与反应离子发生离子-分子反应产生样品离子[44-45]. APCI电离的样品需加热气化，因此需要待测样品沸点较低，加热易气化且应具有较好的热稳定性. APCI一般分析的是分子量在1 000以内的小分子.1.3　MALDIMALDI是另一种常用的商业离子源，尤其适用于聚合物、蛋白质、核酸等大分子样品的质谱分析. MALDI电离可分为三步：先将样品和基质混合，滴加到金属样品板上结晶. 基质一般是能显著吸收紫外光或红外光的小分子，如2, 5-二羟基苯甲酸（DHB），α-氰基-4-羟基肉桂酸（CHCA）等[46]. 脉冲激光束照射样品板后，基质分子吸收激光能量发生电离，样品和基质分子从样品板上脱附出来. 脱附的气体成分含有基质离子、基质分子、样品分子等. 基质离子与脱附出来的样品分子相互作用，诱导样品电离[如图1（c）所示].MALDI对盐和缓冲液等具有较好的耐受性，常用于分析血清、组织等生物样品[47]，MALDI成像技术也得到广泛地应用和发展[48-49]. MALDI通常电离产生单电荷离子，也是一种软电离方式，多用于表征超分子、聚合物及生物大分子等样品的分子量.1.4　EIEI是GC-MS的常用离子源，同APCI类似适合于电离稳定性好、易气化的化合物. 如图1（d）所示：样品气化后从轴向引入离子源腔体内，径向上的加热灯丝产生高能电子束，与样品分子发生碰撞，诱导分子电离[18]. 为提高电子-分子的碰撞概率，电子束两端会加入磁场. 在电子轰击过程中，分子化学键易断裂产生碎片离子，所以EI源是典型的硬电离. 碎片离子能提供化合物的结构信息，且碎裂程度可以通过降低电子束的能量进行调节. 电子束的能量通常为70 eV，可产生丰富的碎片离子[50]. EI源得到的质谱图与质谱仪种类无关，重现性好，后续续表 1离子源分类离子类型应用领域文献场电离（field ionization, FI）强电场不稳定的分子离子分子化合物[31]电喷雾电离（electrospray ionization, ESI）喷雾稳定的分子离子软电离，极性化合物[15]电喷雾脱附电离（desorption electrosprayionization, DESI）喷雾稳定的分子离子直接电离[25]实时直接分析（direct analysis in real time, DART）放电稳定的分子离子直接电离[32]二次离子电离（secondary ionization mass spectrometry, SIMS）微粒诱导脱附稳定的分子离子半导体分析，表面分析，质谱成像分析[33]快原子轰击（fast atom bombardment, FAB）微粒诱导脱附稳定的分子离子软电离，大分子[34]基质辅助激光脱附电离（matrix-assisted laser desorption/ionization, MALDI）光子诱导脱附稳定的分子离子软电离，大分子[35]第 1 期陈银娟，等：质谱在金属有机框架材料结构与应用表征上的研究进展85依据化合物谱库实现样品定性分析.1.5　ICPICP产生的是原子离子，用于对化合物组成的元素进行定性定量分析. 如图2所示，ICP的基本过程如下：蠕动泵载带样品溶液经过雾化器（nebulizer）形成气溶胶并到达雾化室（spray chamber），后经载气（carrier gas）携带进入ICP炬管. ICP炬管通常是由三层同心圆的石英管组成，炬管顶端盘绕着与射频电源相连的感应线圈（RF load coil）. 载气、辅助气（auxiliary gas）和等离子气（plasma gas）通常均为氩气，分别从炬管的内层、中层和外层流入. 高压电火花产生的电子与外层氩气碰撞，诱导其电离产生等离子体. 等离子体在振荡磁场作用下与氩原子碰撞释放欧姆热，致使等离子火焰温度可高达10 000 K. 样品溶液在高温作用下，发生去溶剂化、原子化并电离成原子离子，用质谱检测产生的离子，即为电感耦合等离子体质谱（inductively coupled plasma mass spectrometry, ICP-MS）[51-52]. ICP也存在原子跃迁激发再回到基态的过程，该过程以光子形式进行能量释放，用光谱仪检测光信号，即为电感耦合等离子体原子发射光谱法（inductively coupled plasma optical emission spectroscopy, ICP-OES）. 与ICP-OES 相比，ICP-MS具有灵敏度高、多元素检测和高通量的特点，常用于MOFs材料中元素的精准定量.1.6　MOFs样品离子化质谱检测的是离子，因此用质谱分析MOFs，样品须先进行离子化. Vikse等[53]将ESI-MS表征均相催化剂的电离方式分为三类：inherently-charged system，adventitiously-charged system以及intention-ally-charged system. 第一类，化合物本身带电，可用ESI-MS直接分析. 第二类，化合物是中性分子，在ESI电离过程中丢失负离子（如I−, Cl−）或者结合氢质子/碱金属离子发生离子化. 第三类，通过在化合物上引入酸/碱基团诱导化合物发生电离，同时保持化合物的立体效应和电子效应. 尽管离子化方式很多，但由于各类化合物状态、性质等差异性，还没有通用的离子源可以有效电离所有样品. 因此，在用质谱表征MOFs时，应根据化合物的类型、性质及常见商业离子源的特征合理选择离子化方式. 此外，由于MOFs配体种类及金属中心多种价态的复杂性，在分析质谱结果时，除查找常见的加H+或者加Na+质谱峰外，还应考虑其他的离子类型. 表2列举了用ESI、APCI、MALDI及EI电离MOFs时的样品要求及可能产生的离子类型.2　MOFs材料的质谱表征质谱表征的是离子的质荷比（m/z），高分辨质谱和串级质谱分析（tandem mass spectrometric analysis）(a) (c)(b)(d)magnetmagnettrap electronbeamsampleinletvaporizerrepellerfilamentto analyzerionsgas flownebulizer gasLCeffluentheatervaporsolvent,samplechemicalionizationsolvent ionssample ionsMScorona discharge needlemake-up gastylor coneliquid flowlaser pulse50 μm crystal surfacehigh voltagenozzle图1　（a）ESI [36]、（b）APCI [37]、（c）MALDI [36]和（d）EI [36]电离示意图Fig. 1　Schematics of (a) ESI [36], (b) APCI [37], (c) MALDI [36] and (d) EI[36]86分析测试技术与仪器第 29 卷不仅可以确定样品化学组成，而且可以提供样品结构信息. ESI 和APCI 作为LC-MS 的常见接口，可有效监测溶液中MOFs 催化反应等过程. 近年来，在线质谱分析技术的发展，能实时检测反应中间体或产物，对设计高效的MOFs 基催化剂、研究化学反应机理等起到了巨大的推动作用.2.1　精准分子量定性分子量是化合物的基本属性，根据高分辨质谱精准质荷比和同位素峰型，能对MOFs 进行定性分析. 氨基硫脲衍生物相关的金属配合物具有抗菌、抗肿瘤等药理性质，Ülküseven 等[8]合成了以Ni 、Ru 为金属中心，氨基硫脲衍生物为配体的配合物，并用APCI-MS 、NMR 和XRD 等对合成产物进行了表征. Touj 等[9, 56]利用ESI-MS 等表征合成的铜基N -杂环卡宾催化剂，并用于催化合成1, 2, 3-三氮唑. Liu 等[43]采用ESI-MS 等方法表征合成出的一系列含疏水配体的Ru-bda （bda = 2, 2 ' -bipyridine-6, 6 ' -dicarboxylate ）类催化剂，以研究催化剂外层的疏水作用对水的催化氧化的影响. 使用ESI-MS 监测同类催化剂在加入硝酸铈铵（Ce IV）后，观测到催化剂金属中心从Ru II氧化到Ru III的中间体质谱峰，证明引入外层疏水基团是一种调节质子-耦合电子转移反应（proton-coupled electron transfer ）的有效策略[12].该课题组还用ESI-MS 成功捕捉到Ru-bda 在水氧化表 2 常见离子源电离MOFs 样品要求及产生的正离子类型Table 2　Requirements of MOFs analyzed with several commercial ion sources and the common produced positive ions 离子源MOFs 样品正离子类型ESI化合物本身带电或者有极性分子或者极性配体.H 2O ，ACN (ACN=CH 3CN)，CH 3OH 等ESI 常见溶剂.M +, M 2+ [53]（本身带电），[M]+ [12, 54]（丢失电子，氧化），[M+H]+ [12, 43, 55]，[M+A]+ (A=Na +, K +……)[43]，[M-X]+ [A=Cl −, I −, Br −, OTf −（trifluoromethanesulfonate)……] [9, 56-58]，[M+S+H]+ (S=solvent molecule) [12]，[M-L+H]+(L=Ligand)（丢失中性配体）……APCI 非极性或者弱极性. H 2O ，ACN ，CH 3OH 等常见溶剂. 沸点低，热稳定好.MALDI 样品可含盐，难溶于H 2O ，ACN ，CH 3OH 等常见溶剂. 尤其适合大分子；有合适基质.EI 沸点低，热稳定好.(a)(c)temperature (K) ±10%(b)ion detectorion opticsinterfaceskimmer cone sampler coneICP torchnebulizerspray chamberperistaltic pumpRF power supplymechanical pumpturbomolecularpumpturbomolecularpumpquartz torchRF load coilRF voltage induces rapid oscillation of Ar ions andelectronssample aerosl is carried throughthe centre of the plasmaauxiliary or coolant gas carrier gasplasma gassamplequadrupole mass filter6 0006 2006 5006 8008 00010 000图2　(a) ICP-MS 仪器结构、(b) ICP 电离和 (c) 温度分布示意图[51]Fig. 2　Schematic diagrams of (a) ICP-MS, (b) ICP ionization and (c) temperature distribution[51]第 1 期陈银娟，等：质谱在金属有机框架材料结构与应用表征上的研究进展87催化过程中Ru III的准七配位中间体（如图3所示）[11].2.2　中间体监测及反应机理分析化学反应中间体监测是分析反应机理的有效途径，溶液中的反应中间体因含量低、寿命短、副反应多以及体系复杂等原因，中间体监测更具挑战.质谱分析灵敏度高，尤其是ESI 和APCI 可以作为质谱与液相色谱联用的接口，能分析混合物，有效捕获中间体信息. Rh 2(MEPY)4 (MEPY=methyl pyroglutamate) 是一种用于立体选择性转化的高效催化剂，其合成过程中会产生十多种不同的Rh 配合物，体系十分复杂. Welch 等[59]利用HPLC-ESI-MS 在线检测Rh 2(MEPY)4催化剂合成的不同反应时间中间产物Rh 2(OAc)n (MEPY)m （OAc=CH 3OO)的动态变化（如图4所示），结果表明除目标催化剂(a)(b)699.080 3701.079 5702.078 9703.078 2704.078 9705.077 9705.077 6706.078 0707.078 9708.081 4699.079 8701.075 3702.077 4703.076 5704.077 1706.080 7707.078 8708.081 5m /z699700701702703704705706707708709710m /z699700701702703704705706707708709710704.070 1703.071 1705.072 9706.071 0707.073 7708.076 2698.072 5700.071 7701.071 0702.070 4m /zm /z696698700702704706708710704.071 0703.071 4705.073 8706.071 4707.074 5708.077 6698.072 5700.072 3701.071 4702.071 4696698700702704706708710图3　（a）C 30H 26N 4O 10Ru II催化剂加入Ce IV盐前的质谱图(上层[C 30H 26N 4O 10Ru II+H]+理论谱，下层实验谱)，（b ）加入Ce IV盐后的质谱图（上层[C 30H 26N 4O 10Ru III ]+理论谱，下层实验谱）[11]Fig. 3　(a) Mass spectra of C 30H 26N 4O 10Ru IIcatalyst without Ce IV(upper: theoretical MS of [C 30H 26N 4O 10Ru II+H]+, lower:experimental MS of catalyst) and (b) with Ce IV(upper: theoretical MS of [C 30H 26N 4O 10Ru III ]+, lower: experimental MS ofcatalyst with Ce IV )[11]Rh 2 (AC)4Rh 2 (OAc)4Rh 2 (MEPY)4before heatingheat applied 24681012t /mint /mint /mint /mint /min24681012246810122468101224681012Rx. turns purple t =1 hr t =2 hr t =3 hr t =4 hr M−O=428 amu Rh 2 (OAc)3 (MEPY)1M+H=526 amuRh 2 (OAc)2 (MEPY)2M+H=609 amuRh 2 (OAc)1 (MEPY)3M+H=692 amuRh 2 (MEPY)4M+H=775 amut =5 hrMonitoring formation of Rh 2 (MEPY)4 using LC-MS with flow injection analysis40 00020 00080 00060 00040 00020 000125 000100 00075 00050 00025 000200 000150 000100 00050 0001 500 0001 000 000500 000图4　LC-MS 检测Rh 2(MEPY)4形成中各物种变化[59]Fig. 4　Monitoring formation of Rh 2(MEPY)4 using LC-MS with flow injection analysis[59]88分析测试技术与仪器第 29 卷外，还产生二取代和三取代异构体产物. Han 等[10]利用ESI-MS 研究了铜基MOFs 的生长机理，检测到结合H 2O 、甲醇、N , N -二甲基甲酰胺（DMF ）溶剂分子的MOFs 质谱峰，推测溶剂分子参与MOFs 形成过程并影响产生的MOFs 连接体（linker ）的含量.Salmanion 等[60]采用ESI-MS 研究析氧反应中Ni-Fe 基MOFs 催化剂的变化，在KOH 溶液中，检测到单个连接体，脱羧连接体等质谱峰，并结合NMR 结果推测在KOH 条件下连接体不稳定，导致催化剂易发生降解.2.3　质谱表征MOFs 应用基于质谱灵敏度高、检测速度快的优势，质谱常用于MOFs 精准分子量定性. 近年来，新型的质谱检测技术、原位在线分析越来越多地用于MOFs 材料及其应用表征. Welch 等[59]研究Rh 2(MEPY)4催化剂合成的不同反应时间中间产物变化，并进一步利用HPLC-ICP-MS 对中间体进行了动力学分析.Zhang 等[61]研究分子催化水氧化的反应机理，利用原位电化学质谱，首次报道了[(L 2−)Co IIIOH]和[(L 2−)Co IIIOOH]两种配体-中心-氧化中间体（ligand-centered-oxidation intermediate ），并进一步设计18O 标记实验，试用串级质谱对反应中间体进行确认，为单点催化水氧化的亲核进攻机理提供了有力证据[如图5（a ）（b ）所示]. Ren 等[62]利用质子转移反应-飞行时间质谱（PRT-TOF-MS ）在线检测到电催化还原二氧化碳过程中C1-C4产物及中间体，发现甲醛和乙醛并不是反应生成甲醇和乙醇/乙烯的主要中间体，丙醛还原是正丙醇生成的主要途径[如图5（c ）（d ）所示].MOFs 除用作催化剂外，还用于化合物吸附和(a)(c)PB WOC Intermediates(b)(d)100E =1.2 VE =1.5 V500Micro-EC cell nanospary emitterCarbon UMEPiezoelectric pistolO H OH O−(2e +H )−(e +H )−(e +H )−H (L ) Co (L ) Co =O (L ) Co =(L ) Co =O′(L ) Co O H(L ) Co OO HWNAThis work2 mmMS inletOOO ON N NN Co GC-PTR-TOF-MS Operando PTR-TOF-MSAnode AEM GDEFlow cell Flow cell FlowmeterFlowmeterPTR-TOF-MSYellow and maroon paths do not open at the same timeGas flowGCN gasCO ga_CO gasR e l a t i v e a b u n d a n c e 100500R e l a t i v e a b u n d a n c e440445450455460465470440445450455m /zm /z460465470445 [L 2−) CO III −O]−445 [L 2−) CO III−O]−[(L 2−) CO III −O+H 2O]−463[(L 2−) CO III −O+H 2O]−463[(L 2−) CO III −OO]−4618×10−0.5−2.0E (V) versus Hg/Hg/HgO I n t e n s i t y /a .u .7×106×105×104×103×102×101×100I n t e n s i t y /a .u .7×1012×1010×108×106×104×102×100255006×105×104×103×102×101×100CH CH CHOCu-1 GDE, 3.5 mol/L KOHCH CH CH OH and C H CH CHOC H OH and C H CH CHOC H OH and C H CH CH CHOCH CH CH OH and C H 0400800t /s t /s1 200 1 60000200400600800 1 000 1 200t /s0200400600800 1 000 1 200t /s2004006008001 0001 200−100−200−300−400−500J /(m A c m )I n t e n s i t y /a .u .J/(mA cm )25500J/(mA cm )图5　原位 EC-MS 和PRT-TOF-MS 在线分析MOFs 催化反应的装置及检测结果（a ）原位电化学质谱装置示意图及提出的水氧化机理[61]，（b ）Co 氧化物及超氧化物中间体质谱图[61]，（c ）PTR-TOF-MS 与气相离线使用（黄色）和在线检测（褐色）仪器示意图[62]，（d ）PTR-TOF-MS 在线检测C2，C3产物结果[62]Fig. 5　Schematic and analysis results of in situ EC-MS setup [61]and PRI-TOF MS instrument[62](a) schematic illustration of in situ EC-MS setup and proposed mechanism of water oxidation, (b) mass spectra of cobalt-oxo and cobalt-peroxo intermediates, (c) operation schematic of PTR-TOF-MS when coupled to a gas chromatograph (yellow line) and when used for operando measurements (maroon line), (d) operando measurement of C2 and C3 products第 1 期陈银娟，等：质谱在金属有机框架材料结构与应用表征上的研究进展89固相微萃取等样品前处理过程，供后续质谱进行样品分析，在环境等领域广泛应用[63-65]. Suwannakot等[66]将耐水性好的MOFs 材料，如ZIF-8、UiO-66、MIL88-A 等设计成探针，用于环境水样品中全氟辛酸（perfluorooctanoic acid, PFOA ）的吸附和快速预浓缩，并用纳升ESI-MS 对PFOA 进行检测，实现PFOA 的快速检测（<5 min ）和高灵敏度定量（ng/L ）.Jia 等[67]在MOFs 外层进行疏水性微孔有机网络修饰，用于吸附环境水样、PM2.5和食物样品中的多环芳烃（PAHs ），并进一步用GC-MS/MS 分析了PAHs 的种类和含量. 在生物领域，孕酮在哺乳类动物怀孕和生长中起重要作用，常规GC-MS 和LC-MS 检测孕酮需要复杂的样品前处理过程，Li 等[68]利用氨基修饰的MOFs 材料对生物样品中的孕酮进行固相微萃取处理，并用DART-MS 进行快速定量.3　总结与展望作为一种高灵敏度、高分辨率的快速分析手段，质谱已广泛用于MOFs 材料精准分子量定性、中间体监测、反应机理分析及MOFs 材料多领域应用上. 在MOFs 材料电离方面，由于样品稳定性、溶解性、分子量及溶液基质等限制，仍有少量体系因不能电离无法用质谱分析. 在反应机理研究方面，离线分析已很难满足需求，联用设备、实时分析已成为新型利器，质谱用于MOFs 体系的深入研究任重道远.参考文献：Jiao L, Wang Y, Jiang H L, et al. Metal-organic frame-works as platforms for catalytic applications [J ]. Ad-vanced Materials (Deerfield Beach, Fla)，2018，30（37）：e1703663.［ 1 ］Yang S S, Shi M Y, Tao Z R, et al. Recent applica-tions of metal-organic frameworks in matrix-assisted laser desorption/ionization mass spectrometry [J ].Analytical and Bioanalytical Chemistry ，2019，411（19）：4509-4522.［ 2 ］Zhang Y J, Mao F X, Wang L J, et al. Recent ad-vances in photocatalysis over metal-organic frame-works-based materials [J ]. Solar RRL ，2020，4 （5）：1900438.［ 3 ］He H B, Li R, Yang Z H, et al. Preparation of MOFsand MOFs derived materials and their catalytic applic-ation in air pollution: a review [J ]. Catalysis Today ，2021，375 ：10-29.［ 4 ］Mu X Y, Wang W K, Sun C C, et al. Recent progresson conductive metal-organic framework films [J ]. Ad-vanced Materials Interfaces ，2021，8 （9）：2002151.［ 5 ］Raptopoulou C P. Metal-organic frameworks: synthet-ic methods and potential applications [J ]. Materials (Basel, Switzerland)，2021，14 （2）：310.［ 6 ］Jaffar Z, Yunus N M, Shaharun M S, et al. Incorpor-ated metal-organic framework hybrid materials for gas separation, catalysis and wastewater treatment [J ]. Pro-cesses ，2022，10 （11）：2368.［ 7 ］Ülküseven B, Bal-Demirci T, Akkurt M, et al. Chelatestructures of 5-(H/Br)-2-hydroxybenzaldehyde-4-allyl-thiosemicarbazones (H 2L): synthesis and structural characterizationsof[Ni(L)(PPh 3)]and[Ru(HL)2(PPh 3)2][J ]. Polyhedron ，2008，27 （18）：3646-3652.［ 8 ］Touj N, Özdemir I, Yaşar S, et al. An efficient (NHC)Copper (I)-catalyst for azide-alkyne cycloaddition re-actions for the synthesis of 1, 2, 3-trisubstituted triazoles: Click chemistry [J ]. Inorganica Chimica Acta ，2017，467 ：21-32.［ 9 ］Han J L, Chen S M, Zhou X C, et al. Uncovering growth species of multivariate MOFs in liquid phase by mass spectrometry [J ]. Chinese Chemical Letters ，2022，33 （8）：3993-3998.［ 10 ］Liu T Q, Li G, Shen N N, et al. Isolation and identific-ation of pseudo seven-coordinate Ru(III) intermediate completing the catalytic cycle of Ru-bda type of water oxidation catalysts [J ]. CCS Chemistry ，2022，4 （7）：2481-2490.［ 11 ］Liu T Q, Li G, Shen N N, et al. Promoting proton transfer and stabilizing intermediates in catalytic wa-ter oxidation via hydrophobic outer sphere interac-tions [J ]. Chemistry (Weinheim an Der Bergstrasse,Germany)，2022，28 （24）：e202104562.［ 12 ］Bedia J, Muelas-Ramos V, Peñas-Garzón M, et al. A review on the synthesis and characterization of metal organic frameworks for photocatalytic water purifica-tion [J ]. Catalysts ，2019，9 （1）：52.［ 13 ］Zhou Q, Chen J J, Jin B, et al. Modification of ZIF-8on bacterial cellulose for an efficient selective capture of U(VI)[J ]. Cellulose ，2021，28 （9）：5241-5256.［ 14 ］Fenn J B, Mann M, Meng C K, et al. Electrospray ion-ization for mass spectrometry of large biomolecules [J ]. Science ，1989，246 （4926）：64-71.［ 15 ］Fenn J B, Mann M, Meng C K, et al. Electrospray ion-ization-principles and practice [J ]. Mass Spectrometry Reviews ，1990，9 （1）：37-70.［ 16 ］Horning E C, Horning M G, Carroll D I, et al. New pi-cogram detection system based on a mass spectromet-er with an external ionization source at atmospheric［ 17 ］90分析测试技术与仪器第 29 卷pressure [J ]. Analytical Chemistry ，1973，45 （6）：936-943.Bleakney W. A new method of positive ray analysis and its application to the measurement of ionization potentials in mercury vapor [J ]. Physical Review ，1929，34 （1）：157-160.［ 18 ］Nier A O. A mass spectrometer for routine isotope abundance measurements [J ]. Review of Scientific In-struments ，1940，11 （7）：212-216.［ 19 ］Karas M, Hillenkamp F. Laser desorption ionization of proteins with molecular masses exceeding 10, 000daltons [J ]. Analytical Chemistry ，1988，60 （20）：2299-2301.［ 20 ］Bahr U, Deppe A, Karas M, et al. Mass spectrometry of synthetic polymers by UV-matrix-assisted laser de-sorption/ionization [J ]. Analytical Chemistry ，1992，64（22）：2866-2869.［ 21 ］Rosen A L, Hieftje G M. Inductively coupled plasma mass spectrometry and electrospray mass spectro-metry for speciation analysis: applications and instru-mentation [J ]. Spectrochimica Acta Part B:Atomic Spectroscopy ，2004，59 （2）：135-146.［ 22 ］Klampfl C W, Himmelsbach M. Direct ionization methods in mass spectrometry: An overview [J ]. Ana-lytica Chimica Acta ，2015，890 ：44-59.［ 23 ］Awad H, Khamis M M, El-Aneed A. Mass spectro-metry, review of the basics: ionization [J ]. Applied Spectroscopy Reviews ，2015，50 （2）：158-175.［ 24 ］Takáts Z, Wiseman J M, Gologan B, et al. Mass spec-trometry sampling under ambient conditions with de-sorption electrospray ionization [J ]. Science ，2004，306 （5695）：471-473.［ 25 ］张兴磊, 张华, 王新晨, 等. 直接离子化装置研究新进展[J ]. 分析化学，2018，46（11）：1703-1713.[ZHANG Xinglei, ZHANG Hua, WANG Xinchen, et al. Advances in ambient ionization for mass spectro-metry [J ]. Chinese Journal of Analytical Chemistry ，2018，46 （11）：1703-1713.]［ 26 ］Verlinden J, Gijbels R, Adams F. Applications of spark-source mass spectrometry in the analysis of semiconductor materials A review [J ]. Journal of Ana-lytical Atomic Spectrometry ，1986，1 （6）：411-419.［ 27 ］Hoffmann V, Kasik M, Robinson P K, et al. Glow dis-charge mass spectrometry [J ]. Analytical and Bioana-lytical Chemistry ，2005，381 （1）：173-188.［ 28 ］Lemr K, Borovcova L. Chemical Ionization [J ].Chemicke Listy ，2020，114 （3）：163-168.［ 29 ］Raffaelli A, Saba A. Atmospheric pressure photoioniz-ation mass spectrometry [J ]. Mass Spectrometry Re-views ，2003，22 （5）：318-331.［ 30 ］Lattimer R P. Pyrolysis field ionization mass spectro-metry of polyolefins [J ]. Journal of Analytical and Ap-［ 31 ］plied Pyrolysis ，1995，31 ：203-225.Steiner R R, Larson R L. Validation of the direct ana-lysis in real time source for use in forensic drug screening [J ]. Journal of Forensic Sciences ，2009，54 （3）：617-622.［ 32 ］Benninghoven A. Chemical analysis of inorganic and organic surfaces and thin films by static time-of-flight secondary ion mass spectrometry (TOF-SIMS)[J ].Angewandte Chemie International Edition in English ，1994，33 （10）：1023-1043.［ 33 ］Sunner J. Ionization in liquid secondary ion mass spec-trometry (LSIMS)[J ]. Organic Mass Spectrometry ，1993，28 （8）：805-823.［ 34 ］Bakhtiar R, Nelson R W. Electrospray ionization and matrix-assisted laser desorption ionization mass spec-trometry [J ]. Biochemical Pharmacology ，2000，59（8）：891-905.［ 35 ］Ekman R. Mass spectrometry: instrumentation, inter-pretation, and applications [M ]. Hoboken, NJ: John Wiley & Sons, 2009.［ 36 ］Bruins A P. Atmospheric-pressure-ionization mass spectrometry:II Applications in pharmacy, biochem-istry and general chemistry [J ]. TrAC Trends in Ana-lytical Chemistry ，1994，13 （2）：81-90.［ 37 ］Dole M, Mack L L, Hines R L, et al. Molecular beams of macroions [J ]. The Journal of Chemical Physics ，1968，49 （5）：2240-2249.［ 38 ］Iribarne J V, Thomson B A. On the evaporation of small ions from charged droplets [J ]. The Journal of Chemical Physics, 1976, 64(6): 2287-2294.［ 39 ］Blades A T, Ikonomou M G, Kebarle P. Mechanism of electrospray mass spectrometry Electrospray as an electrolysis cell [J ]. Analytical Chemistry ，1991，63（19）：2109-2114.［ 40 ］Kebarle P, Verkerk U H. Electrospray: from ions in solution to ions in the gas phase, what we know now [J ]. Mass Spectrometry Reviews, 2009, 28(6): 898-917.［ 41 ］Pramanik B N, Ganguly A K, Gross M L. 电喷雾质谱应用技术[M ]. 蒋宏键, 俞克佳, 译. 北京: 化学工业出版社, 2005: 11-33.［ 42 ］Liu T Q, Li G, Shen N N, et al. Hydrophobic interac-tions of Ru-bda-type catalysts for promoting water ox-idation activity [J ]. Energy & Fuels ，2021，35 （23）：19096-19103.［ 43 ］Sakairi M, Kato Y. Multi-atmospheric pressure ionisa-tion interface for liquid chromatography-mass spectro-metry [J ]. Journal of Chromatography A ，1998，794 （1-2）：391-406.［ 44 ］Ayala-Cabrera J F, Montero L, Meckelmann S W, et al. Review on atmospheric pressure ionization sources for gas chromatography-mass spectrometry Part I:［ 45 ］第 1 期陈银娟，等：质谱在金属有机框架材料结构与应用表征上的研究进展91Current ion source developments and improvements in ionization strategies [J ]. Analytica Chimica Acta ，2023，1238 ：340353.代莉莉. 基质辅助激光解析电离飞行时间质谱分析合成聚合物样品制备的研究进展[J ]. 分析测试技术与仪器，2022，28（4）：375-383. [DAI Lili. Pro-gress on sample preparation of synthetic polymers ana-lysis by matrix assisted laser desorption ionization time-of-flight mass spectrometry [J ]. Analysis and Testing Technology and Instruments ，2022，28 （4）：375-383.]［ 46 ］Villanueva J, Philip J, Entenberg D, et al. Serum pep-tide profiling by magnetic particle-assisted, automated sample processing and MALDI-TOF mass spectro-metry [J ]. Analytical Chemistry ，2004，76 （6）：1560-1570.［ 47 ］McDonnell L A, Heeren R M A. Imaging mass spec-trometry [J ]. Mass Spectrometry Reviews ，2007，26（4）：606-643.［ 48 ］Cornett D S, Reyzer M L, Chaurand P, et al. MALDI imaging mass spectrometry: molecular snapshots of biochemical systems [J ]. Nature Methods ，2007，4（10）：828-833.［ 49 ］Lemr K, Borovcova L. Electron ionization [J ].Chemicke Listy ，2020，114 （2）：101-105.［ 50 ］Picó Y. Food Toxicants Analysis [M ]. Elsevier Sci-ence Ltd, 2007.［ 51 ］Abou-Shakra F R. Bioanalytical Separations Hand-book of Analytical Separations [M ]. Elsevier. 2003:351-371.［ 52 ］Vikse K L, Ahmadi Z, Scott McIndoe J. The applica-tion of electrospray ionization mass spectrometry to homogeneous catalysis [J ]. Coordination Chemistry Reviews ，2014，279 ：96-114.［ 53 ］Ricci P, Krämer K, Cambeiro X C, et al. Arene-metal π-complexation as a traceless reactivity enhancer for C-H arylation [J ]. Journal of the American Chemical Society ，2013，135 （36）：13258-13261.［ 54 ］Nemykin V N, Galloni P, Floris B, et al. Metal-free and transition-metal tetraferrocenylporphyrins part 1:synthesis, characterization, electronic structure, and conformational flexibility of neutral compounds [J ].Dalton Transactions (Cambridge, England:2003)，2008（32）：4233-4246.［ 55 ］Touj N, Chakchouk-Mtibaa A, Mansour L, et al. Syn-thesis, spectroscopic properties and biological activity of new Cu(I) N-Heterocyclic carbene complexes [J ].Journal of Molecular Structure ，2019，1181 ：209-219.［ 56 ］Wu L, Tang M, Jiang L, et al. Synthesis of contra-hel-ical trefoil knots with mechanically tuneable spin-cros-sover properties [J ]. Nature Synthesis ，2023，2 （1）：17-［ 57 ］25.Valle H U, Riley K M, Russell D E, et al. Synthesis,characterization, and structure of a [Cu(phen)2 (OTf)]OTf complex: an efficient nitrogen transfer pre-cata-lyst [J ]. ChemistrySelect ，2018，3 （18）：5143-5146.［ 58 ］Welch C, Tu Q, Wang Ti B, et al. Observations of rho-dium-containing reaction intermediates using HPLC with ICP-MS and ESI-MS detection [J ]. Advanced Synthesis & Catalysis ，2006，348 （7-8）：821-825.［ 59 ］Salmanion M, Nandy S, Chae K H, et al. Further in-sight into the conversion of a Ni-Fe metal-organic framework during water-oxidation reaction [J ]. Inor-ganic Chemistry ，2022，61 （12）：5112-5123.［ 60 ］Zhang X H, Chen Q F, Deng J T, et al. Identifying metal-oxo/peroxo intermediates in catalytic water ox-idation by in situ electrochemical mass spectrometry [J ]. Journal of the American Chemical Society ，2022，144 （39）：17748-17752.［ 61 ］Ren H J, Kovalev M, Weng Z Y, et al. Operando pro-ton-transfer-reaction time-of-flight mass spectrometry of carbon dioxide reduction electrocatalysis [J ]. Nature Catalysis ，2022，5 （12）：1169-1179.［ 62 ］Tang J, Ma X H, Yang J, et al. Recent advances in metal-organic frameworks for pesticide detection and adsorption [J ]. Dalton Transactions (Cambridge, Eng-land:2003)，2020，49 （41）：14361-14372.［ 63 ］Llompart M, Celeiro M, García-Jares C, et al. Environ-mental applications of solid-phase microextraction [J ].TrAC Trends in Analytical Chemistry ，2019，112 ：1-12.［ 64 ］Musarurwa H, Tavengwa N T. Smart metal-organic framework (MOF) composites and their applications in environmental remediation [J ]. Materials Today Com-munications ，2022，33 ：104823.［ 65 ］Suwannakot P, Lisi F, Ahmed E, et al. Metal-organic framework-enhanced solid-phase microextraction mass spectrometry for the direct and rapid detection of per-fluorooctanoic acid in environmental water samples [J ]. Analytical Chemistry ，2020，92 （10）：6900-6908.［ 66 ］Jia Y Q, Su H, Wang Z H, et al. Metal-organic frame-work@microporous organic network as adsorbent for solid-phase microextraction [J ]. Analytical Chemistry ，2016，88 （19）：9364-9367.［ 67 ］Li L N, Chen Y L, Yang Y G, et al. Rapid and sensit-ive analysis of progesterone by solid-phase extraction with amino-functionalized metal-organic frameworks coupled to direct analysis in real-time mass spectro-metry [J ]. Analytical and Bioanalytical Chemistry ，2020，412 （12）：2939-2947.［ 68 ］92分析测试技术与仪器第 29 卷。

Containing Pyridine RingRuifei Su,Hongyu Wei,Xin Zhang,Sufang Ma,Jing Yan,Yuan Cui,and Zhao Zhang* College of Chemistry and Chemical Engineering,Shanxi University,Taiyuan030006,Shanxi,China*E-mail:z.zhang@Additional Supporting Information may be found in the online version of this article.Received October29,2011DOI10.1002/jhet.1639Published online2December2013in Wiley Online Library().A series of novel monodisperse,well-defined molecules with a pyridine core and carbazole arms weresynthesized by simple procedures with Iodo-reaction and Ullmann reaction.Their structures were confirmed byIR,1H NMR,13C NMR,and elementary analysis.Moreover,thefluorescence spectra showed that thesecompounds exhibited strongfluorescence with the maximum wavelengths ranging from373to385nm.J.Heterocyclic Chem.,51,669(2014).INTRODUCTIONRecently,monodisperse,well-defined,p-conjugated molecules have attracted much attention in materials science[1]because of their potential applications in organic light-emitting diodes,solar cells,field-effect transistors,and so on[2–4].The conjugated systems,firstly, may become possible alternatives to linear-conjugated oligomers in optoelectronic applications.[5]Secondly,the communication between the conjugated arms and core may result in some unique functionality[6].Traditionally,pyridine is a prototypical molecule and is widely used as a chromophore in varieties of materials science applications owing to its desirable photophysical properties,thermal stability,and chemical stability[7]. The research on the pyridine moieties in materials applica-tion mainly concentrates on electrophosphorescent metal complexes because of their enhanced absolute photolumi-nescence quantum yields[8].Compared with benzene, carbazole andfluorine,which are important building blocks and intermediates in materials chemistry[9,14,15], pyridine is an electron-deficient aromatic heterocycle,with a localized lone pair of electrons in a sp2orbital on the nitrogen atom[10].Consequently,compounds containing pyridine moiety display electron-transporting abilities and can undergo modification of their optical properties[11]. It has also been shown that a conjugated molecule containing pyridine in the main chain exhibits potential applications in optoelectronics and photonics[12].One of the strategies for optimizing their properties and increasing their stability involves the insertion offive-membered heteroaromatics into the p-conjugated backbone[13]. Additionally,carbazole is a common heterocyclic compound with interesting photochemistry and electro-chemistry;it can be functionalized at3-position,6-position, or9-position readily and linked to other molecular moieties covalently.Thus,the design and synthesis of carbazole-based molecules are also attractive[14].Carbazole deriva-tives are widely used as building blocks for potential organic semiconductors and organic light-emitting diodes[15]. Despite the huge amount of work already invested in these various applications,it is clear that further progress in thesefields requires an intensification of the research effort focused on the design and synthesis of new compounds with electrochemical,optical,and electronic properties specifically tailored for each type of application.In this article,a series of star-shaped,well-defined, p-conjugated molecules were designed and synthesizedwith pyridine as the central blocks and carbazole as the outer blocks.The formation of C-N bond would be bene ficial to the molecular electronic transition among carbazole units [14a].The UV –vis absorption spectra and luminescent spectra were determined;moreover,the in fluences of absorption and fluorescence performance in different solvent were studied.It was found that these carbazole derivatives showed strong fluorescence emission.RESULTS AND DISCUSSIONThe synthetic routes of the five carbazole derivatives are shown in Scheme 1.The 2,6-bis(carbazolyl)pyridine (1a )was synthesized from carbazole as starting material through a modi fied Ullmann pounds 2a ,3a ,4a ,and 5a were synthesized,and the molar ratios of 1a /KI/KIO 3were 1:1.1:1.1,1:2.1:2.1,1:3.1:3.1,and 1:4.1:4.1,respectively.After iodination of 1a ,the intermediates with different numbers of iodine substituents were directly reacted with carbazole.Puri fication by column chromatography afforded pure 2,6-bis(carbazolyl)pyridine derivatives with different numbers of carbazole units.All carbazole-based compounds were obtained as white powders.The compounds were characterized with IR,1H NMR,13C NMR,and elemental analysis.The objective compounds have good solubilityin common solvents,such as THF,dichloromethane,chloro-form,toluene,and ethyl acetate.The UV –vis absorption and photoluminescence spectra of all carbazole-based compounds in CH 2Cl 2solution were measured and shown in Table 1.The UV –vis absorption spectra of the objective compounds were shown in Figure 1.All the compounds exhibited intense transitions in the UV region from 241to 342nm.For instance,a broad absorption band was observed at about 341nm for each compound,which indicated the p !p *electron transfer of the entire conjugated backbone,and other broad bands in the range of 240–300nm were derived from the carbazoleScheme 1.Reagents and conditions:(i)carbazole,K 2CO 3,KOH,Cu,DMF,152 C;(ii)KI,KIO 3,CH 3COOH.Table 1Absorption and fluorescent emission data in CH 2Cl 2for 1a ,2b ,3b ,4b ,and 5b .Compound l abs max (nm)l em max (nm)a1a 241,292,3403732b 242,293,3413763b 242,293,3413804b 243,293,3413825b244,293,342385aExcited at the wavelength of maximum absorption.transitions.It was also observed thatfive compounds had quite similar UV–vis absorption characteristics because of the large torsion angle between the carbazoles[16].The UV–vis absorption of the compound1a in different organic solvents was shown in Figure2.Most electronic transitions in these compounds are the transfer of p!p* bonds.The energy necessary for electron transfer is decreasing with increasing the solvent polarity,and the significant red shift(from236nm in cyclohexane to 249nm in THF)of the absorption band was observed as the solvent polarity increased.The photoluminescence spectra of the target compounds were shown in Figure3.All com-pounds were found to give strongfluorescent peaks,and it was also observed that the wavelengths of emission spectrum increased as the number of carbazole moieties increased.It was clear that the conjugated degree of the objective compounds would be enlarged with the increase of carbazole moieties[17].Take compound1a for instance,as shown in Figure4,thefluorescence spectrum of compound1a followed general solvent effects.Therefore,the significant red shift of the emission band was observed from338nm in cyclohexane to373nm in dichloromethane with in-creasing the dielectric constant of the paring the spectra of1,4-bis(carbazolyl)benzene,3,6-bis(carbazolyl) carbazole,and3,6-bis(carbazolyl)fluorene with the spectra of2,6-bis(carbazolyl)pyridine(1a),it indicated that repla-cing the benzene,fluorene,or carbazole group with pyridine group led to a significant red shift in both absorption and emission spectra[16a,18].Therefore,it was clear that a compound that contains a pyridine ring could improve its optical properties.In conclusion,we had developed a series of novel com-pounds with pyridine as the central unit and the carbazole as substituents at the3-position and/or6-position of the carbazole group.The key to the synthesis ofintermediate Figure1.UV–vis absorption spectra of1a,2b,3b,4b,and5b in CH2Cl2with the concentration of1Â10À5M.[Colorfigure can be viewed in theonline issue,which is available at.]Figure2.UV–vis absorption spectra of1a in different solvents with theconcentration of1Â10À5M.[Colorfigure can be viewed in the onlineissue,which is available at.]Figure4.Photoluminescence spectra of1a in different solvents with theconcentrations of1Â10À6M.[Colorfigure can be viewed in the onlineissue,which is available at.]Figure3.Photoluminescence spectra of1a,2b,3b,4b,and5b in CH2Cl2with the concentration of1Â10À6M.[Colorfigure can be viewed in theonline issue,which is available at .]iodines was the different quantity of potassium iodide and potassium iodate.At atmospheric pressure,the Ullmanncoupling reaction took place using Cu,KOH,and K2CO3as catalysts without the protection of N2in DMF.It was observed that thefive compounds showed strongfluores-cence emission.Therefore,these carbazole derivatives hadthe potential to be applied in developing optoelectronic devices.Further studies including the potential applicationsof these carbazole derivatives using other methods are inprogress in our laboratory.EXPERIMENTALGeneral experimental procedures.All chemicals were purchased from Sinopharm Chemical Reagent Beijing Co.,Ltd (Beijing,China)and used without further purification.1H NMR and13C NMR spectra were recorded on a Brucker DRX300MHz spectrometer(Bruker Co.,Germany)at room temperature.IR spectra were recorded on a Shimadzu8400-S(wave numbers in cmÀ1)(Shimadzu Co.,Japan).UV–vis andfluorescence spectra were recorded on an Agilent Tichnologies HP8543 spectrophotometer(Agilent Technologies Co.,California,USA) and a Perkin-Elmer LS55Bluminescence spectrometer(Perkin Elmer lnc.,Massachusetts,USA),respectively.The elemental analyses were performed using a VARIO EL III elemental analysis system(Elementar Co.,Germany).General procedure for the Ullmann reaction[14b,19].A mixture of halogenated compound,the corresponding carbazole and an excess amount of copper,K2CO3,KOH was heated in DMF at152 C.After cooling down to room temperature,the mixture was quenched with50mL NH3•H2O.The precipitate was filtered and washed with NH3•H2O and water.The pure products were isolated by silica gel column chromatography.General procedure for the Iodo-Reaction[20].Compound1a, potassium iodide,andfinely powdered potassium iodate were heated in glacial acetic acid.After cooling to room temperature, the saturated solution of NaHSO3was added to clear I2and KIO3. Then,the mixture was poured into water,and the precipitate was filtered and washed with water.2,6-Bis(carbazolyl)pyridine(1a).The general procedure of Ullmann reaction was followed;a mixture of carbazole(0.53g, 3.2mmol),2,6-dibromopyridine(0.36g,1.5mmol),Cu(0.5g, 7.8mmol),K2CO3(0.44g,3.2mmol),KOH(0.18g,3.2mmol) was heated for72h.The product was purified with column chromatography(petroleum ether/ethyl acetate=10:1,v/v)as a white solid.Yield:84.8%.mp:200–202 C.IR(KBr,cmÀ1): 3105.18,3029.96,2927.74,2003.90,1778.25,1631.67,1564.16, 1546.80,1406.01,1384.79,1218.93,1164.92,1134.07,1122.49, 1093.65,1070.42,1049.20,979.77,786.90,740.61,648.04, 622.96.1H NMR(300MHz,CDCl3,TMS):d7.31–7.44(m,8H), 7.65(d,J=7.8Hz,2H),8.03(d,J=8.1Hz,4H),8.12 (t,J=7.5Hz,5H).13C NMR(75MHz,CDCl3,TMS):d113.16, 116.13,121.36,122.45,125.73,127.56,140.65,141.59,152.73. Anal.Calcd for C29H19N3:C,85.06;H,4.68;N,10.26.Found:C, 84.92;H,4.69;N,10.22.9-(6-(9H-carbazol-9-yl)pyridin-2-yl)-9H-3,90-bicarbazole (2b).The general procedure of Iodo-reaction was followed;a mixture of compound1a(0.82g,2.0mmol),potassium iodide (0.37g,2.2mmol)and potassium iodate(0.47g,2.2mmol)was heated in glacial acetic acid at80 C for8h.Without furtherpurification,the compound2a was the main product in thisiodinated mixture.Then,the general procedure of Ullmannreaction was followed;a mixture of2a(0.54g,1mmol),carbazole(0.2g,1.2mmol),Cu(0.5g,7.8mmol),K2CO3(0.17g,1.2mmol),KOH(0.067g,1.2mmol)was heated in DMF for46h.The product was purified with column chromatography(hexane/chloroform=3:4,v/v)as a white solid.Yield:30.1%.mp:156–158 C.IR(KBr,cmÀ1):3049.25,2923.88,1623.95,1596.95,1571.88,1492.80,1450.37,1377.08,1313.43,1274.86,1230.50,1164.92,1149.50,1118.74,800.40,748.33,723.26,655.75,422.38.1H NMR(300MHz,DMSO-d6,TMS):d7.24–7.52(m,1H),7.60(d,J=8.7Hz,2H),7.89–7.97(m,8H), 8.14(d,J=8.7Hz,2H),8.25(d,J=7.6Hz,7H),8.32–8.55(m,6H).13C NMR(75MHz,CDCl3,TMS):d110.90,112.83,114.17,117.76,120.98,121.61,122.51,123.79,124.73,125.05,126.75,127.33,127.74,128.38,131.61,139.31,140.21,140.88,142.32,143.49,151.65,151.94.Anal.Calcd for C41H26N4:C,85.69;H,4.56;N,9.75,Found:C,85.39;H,4.58;N,9.75.2,6-Di(9H-3,90-bicarbazol-9-yl)pyridine(3b).The synthetic procedure for3a was similar to that of2a,using compound1a (0.82g, 2.0mmol),potassium iodide(0.70g, 4.2mmol),and potassium iodate(0.90g,4.2mmol).Adopting the condition of Ullmann reaction,3a(0.66g,1mmol),carbazole(0.37g, 2.2mmol),Cu(0.5g,7.8mmol),K2CO3(0.30g,2.2mmol),and KOH(0.12g,2.2mmol)were heated pound3b was purified with column chromatography(hexane/chloroform=3:4,v/ v)as a white solid.Yield:37.0%.mp:194–196 C.IR(KBr,cmÀ1): 3047.32,2921.96,2850.59,1623.95,1593.09,1571.88,1448.44, 1313.43,1274.86,1230.50,1188.07,1164.92,1151.42,918.05, 746.40,723.26,653.82,422.38.1H NMR(300MHz,DMSO-d6, TMS):d7.27–7.32(m,5H),7.41(t,J=12.1Hz,9H),7.55 (t,J=9.0Hz,2H),7.68(d,J=9.0Hz,2H),8.02–8.04(m,4H), 8.20–8.26(m,5H),8.38–8.59(m,6H).13C NMR(75MHz,CDCl3, TMS):d110.81,1112.93,114.08,117.98,120.88,121.51,122.27, 122.69,123.69,124.65,126.31,126.69,127.20,128.32,131.57, 139.23,140.81,142.22.Anal.Calcd for C53H33N5:C,86.04;H, 4.50;N,9.46.Found:C,86.11;H,4.48;N,9.44.9-(6-(9H-3,90-Bicarbazol-9-yl)pyridin-2-yl)-6-(9H-carbazol-9-yl)-9H-3,90-bicarbazole(4b).The synthetic procedure for4a was similar to that of2a,using compound1a(0.82g,2.0mmol), potassium iodide(1.02g,6.2mmol),and potassium iodate(1.32g, 6.2mmol).Adopting the condition of Ullmann reaction,4a (0.79g,1mmol),carbazole(0.53g, 3.2mmol),Cu(0.5g, 7.8mmol),K2CO3(0.44g, 3.2mmol),and KOH(0.18g, 3.2mmol)were heated pound4b was purified with column chromatography(petroleum ether/ethyl acetate=15:1, v/v)as a white solid.Yield:40.9%.mp:223–225 C.IR(KBr, cmÀ1):3049.25,2923.88,2852.52,1623.95,1593.09,1496.66, 1450.37,1382.87,1334.65,1278.72,1230.50,1188.07, 1157.21,746.40,723.26.1H NMR(300MHz,DMSO-d6,TMS): d7.26–7.33(m,7H),7.41(d,J=3.6Hz,14H),7.75–7.78(m,3H), 8.07–8.18(m,3H),8.25(t,J=7.2Hz,9H),8.59–8.61(m,2H), 8.75(d,J=2.1Hz,2H).13C NMR(75MHz,DMSO-d6,TMS): d110.89,112.96,114.38,118.78,121.07,121.73,122.51,123.71, 125.90,127.45,131.81,139.26,139.89,140.85,142.08,144.14. Anal.Calcd for C65H40N6:C,86.26;H,4.45;N,9.29.Found:C, 86.19;H,4.46;N,9.28.2,6-Bis(6-(9H-carbazol-9-yl)-9H-3,90-bicarbazol-9-yl)pyridine (5b).The general procedure of Iodo-reaction was followed; compound1a(0.82g, 2.0mmol),potassium iodide(1.36g, 8.2mmol),and potassium iodate(1.75g,8.2mmol)were heatedin glacial acetic acid at117 C for10h.Adopting the condition of Ullmann reaction,5a(0.91g,1mmol),carbazole(0.70g, 4.2mmol),Cu(0.5g,7.8mmol),K2CO3(0.58g,4.2mmol),and KOH(0.24g,4.2mmol)were heated pound5b was purified with column chromatography(petroleum ether/ethyl acetate=15:1,v/v)as a white solid.Yield:52%.mp:>300 C.IR (KBr,cmÀ1):3049.25,2923.88,2848.67,1625.88,1593.95, 1496.66,1450.37,1334.65,1313.43,1280.65,1232.43,1188.07, 1157.21,919.98,879.48,811.98,748.33,723.26,640.23, 4937.74.1H NMR(300MHz,DMSO-d6,TMS):d7.23–7.25 (m,8H),7.32–7.41(m,15H),7.73(d,J=6.2Hz,4H),8.15–8.19 (m,12H),8.32–8.35(m,4H),8.65–8.67(m,4H).13C NMR (75MHz,CDCl3,TMS):d110.653,114.370,116.957,120.598, 120.879,121.400,124.261,126.405,127.017,127.614,132.779, 140.108,142.561,152.444.Anal.Calcd for C77H47N7:C,86.41; H,4.43;N,9.16.Found:C,86.38;H,4.45;N,9.14. Acknowledgments.This work was supported by the Research of the Project by Shanxi Scholarship Council of China(No.200817) and The Science and Technology Project for the Higher Educational Institutes of Shanxi Province of China(No.20080001).REFERENCES AND NOTES[1](a)Tour,J.M.Chem Rev1996,96,537;(b)Kim,D.;Osuka,A.Acc Chem Res2004,37,735.(c)Cao,Y.;Wang,H.-J.Mater Lett 2011,65,340.[2](a)Van Hutten,P. F.;Wildeman,J.;Meetsma, A.; Hadziioannou,G.J Am Chem Soc1999,121,5910;(b)Lee,S.H.; Nakamura,T.;Tsutsui, Lett2001,3,2005;(c)Li,C.-H.;Bo, Z.-S.Polymer2010,51,4273.[3](a)Noma,N.;TsuZuki,T.;Shirota,Y.Adv Mater1995,7, 647;(b)Tang,W.-H.;Hai,J.-F.;Dai,Y.;Huang,Z.-J.;Lu,B.-Q.;Yuan,F.;Tang,J.;Zhang,F.-J.Sol Energy Mater Sol Cells2010,94,1963.[4]Schon,J.H.;Dodabalapur,A.;Kloc,C.;Batlogg,B.Science 2000,290,963.[5](a)Cherioux,F.;Guyard,L.Adv Funct Mater2001,11,305;(b)Sun,Y.-M.;Xiao,K.;Liu,Y.-Q.;Wang,J.-L.;Pei,J.;Yu,G.;Zhu,D.-B.Adv Funct Mater2005,15,818.[6](a)Jiu,T.-G.;Li,Y.-J.;Gan,H.-Y.;Li,Y.-L.;Liu,H.-B.; Wang,S.;Zhou,W.-D.;Wang,C.-R.;Li,X.-F.;Liu,X.-F.;Zhu,D.-B. Tetrahedron2007,63,232;(b)Montes,V.A.;Perez-Bolivar,C.;Estrada, L.A.;Shinar,J.;Anzenbacher,P.J.J Am Chem Soc2007,129,12598.[7](a)Wang,K.-L.;Liou,W.-T.;Liaw, D.-J.;Chen,W.-T. Dyes Pigm2008,78,93;(b)Liaw,D.-J.;Wang,K.-L.;Chang,F.-C. Macromolecules2007,40,3568.[8]Zhen,H.-Y.;Jiang,C.-Y.;Yang,W.;Jiang,J.-X.;Huang,F.; Cao,Y.Chem Eur J2005,11,5007.[9](a)Omer,K.M.;Ku,S.-Y.;Wong,K.-T.;Bard,A.J.J Am Chem Soc2009,131,10733;(b)Zhang,X.;Ji,X.;Jiang,S.-S.;Liu, L.-L.;Weeks,B.L.;Zhang,Z.Green Chem2011,13,1891;(c)Kim,J.; Jin,Y.;Song,S.;Kim,S.H.;Park,S.H.;Lee,K.;Suh,H.Macromolecules 2008,41,8324;(d)El-Khouly,M.E.,Chen,Y.;Zhuang,X.;Fukuzumi,S. J Am Chem Soc2009,131,6370;(e)Zhang,X.;Han,J.-B.;Li,P.-F.;Ji,X.; Zhang,Z.Synth Commun2009,39,3804.[10]Wang,C.-S.;Kilitziraki,M.;Hugh,M.J.A.;Bryce,M.R.; Horsburgh,L.E.;Sheridan,A.K.;Monkman,A.P.;Samuel,I.D.W. Adv Mater2000,12,217.[11](a)Kolev,T.;Koleva,B.B.;Spiteller,M.;Mayer-Figge,H.; Sheldrick,W.S.Dyes Pigm2008,79,7;(b)Jeon,S.O.;Yook,K.S.; Lee,J.Y.Thin Solid Films2010,519,890.[12]Liawa, D.-J.;Wang,K.-L.;Pujari,S.P.;Huang,Y.-C.; Tao, B.-C.;Chen,M.-H.;Lee,K.-R.;Lai,J.-Y.Dyes Pigm2009, 82,109.[13](a)Dalton,L.R.;Sullivan,P.A.;Bale,D.H.Chem Rev2010, 110,25;(b)Luo,J.;Zhou,X.-H.;Jen,A.K.-Y.J Mater Chem2009,19, 7410;(c)He,G.-S.;Tan,L.-S.;Zheng,Q.;Prasad,P.N.Chem Rev2008, 108,1245;(d)Nazeeruddin,M.K.;Baranoff, E.;Grätzel,M.Sol Energy2011,85,1172;(e)Hagfeld,A.T.;Boschloo,G.;Sun,L.; Kloo,L.;Pettersson,H.Chem Rev2010,110,6595;(f)Graetzel,M. Acc Chem Res2009,42,1788;(g)Ooyama,Y.;Harima,Y.Eur J Org Chem2009,2903.[14](a)Xu,T.-H.;Lu,R.;Jin,M.;Qiu,X.;Xue,P.-C.;Bao,C.-Y.; Zhao,Y.-Y.Tetrahedron Lett2005,46,6883;(b)Hyun,A.-R.;Lee,J.-H.; Kang,I.-N.;Park,J.-W.Thin Solid Films2006,509,127;(c)Son,K.S.; Yahiro,M.;Imai,T.;Yoshizaki,H.;Adachi,C.Chem Mater2008, 20,4439.[15](a)Kirkus,M.;Simokaitiene,J.;Grazulevicius,J.V.; Jankauskas,V.Synth Met2010,160,750;(b)Sek,D.;Grabiec,E.; Janeczek,H.;Jarzabek,B.;Kaczmarczyk,B.;Domanski,M.;Iwan,A. Opt Mater2010,32,1514.[16](a)Zhang,Q.;Chen,J.-S.;Cheng,Y.-X.;Wang,L.-X.;Ma,D.-G.;Jing,X.-B.;Wang,F.-S.J Mater Chem2004,14,895;(b)Xu, T.-H.;Lu,R.;Liu,X.-L.;Chen,P.;Qiu,X.-P.;Zhao,Y.-Y.J Org Chem 2008,73,1809.[17]Grubbs,R.H.;Kratz,D.Chem Ber1993,126,149.[18](a)Xing,Y.-J.;Lin,H.-Y.;Wang,F.;Lu,P.Sens Actuators B 2006,114,28;(b)Koene,B.E.;Loy,D.E.;Thompson,M.E.Chem Mater1998,10,2235;(c)Usluer,O.;Demic,S.;Egbe,D.A.M.; Birckner,E.;Tozlu,C.;Pivrikas,A.;Ramil,A.M.;Sariciftci,N.S.Adv Funct Mater2010,10,1.[19](a)Zhao,Z.-H.;Jin,H.;Zhang,Y.-X.;Shen,Z.-H.;Zou,D.-C.;Fan,X.-H.Macromolecules2011,44,1405;(b)Zhang,Q.;Chen, J.-S.;Cheng,Y.-X.;Wang,L.-X.;Ma,D.-G.;Jing,X.-B.;Wang,F.-S. J Mater Chem2004,14,895.[20](a)Pellon,R.F.;Carrasco,R.;Marquez,T.;Mamposo,T. Tetrahedron Lett1997,38,5107;(b)Kimoto,A.;Cho,J.-S.;Higuchi, M.;Yamamoto,K.Macromolecules2004,37,5531.。

第38卷第3期2019年9月中南民族大学学报(自然科学版)Journal of South-Central University for Nationalities(Natural Science Edition)Vol.38No.3Sep.2019一种a,卩不饱和竣酸亚胺酯的合成、表征与晶体结构吴滨，范誌，王吉庆，杨金明*(中南民族大学药学院，武汉430074)摘要报道了一种烯酮亚胺反应活性中间体的重排产物一a,卩不饱和竣酸亚胺酯化合物的合成，并通过核磁共振氢谱和X射线单晶衍射对其结构进行了表征.单晶X-衍射分析表明:该化合物三斜晶系,P-1空间群，晶胞参数a=7.9832(2)A,6=8.3409(2)A,c=14.5288(4)A,a=81.1650(10)°,0=74.4740(10)°,■/=63.9960(10)°,卩= 837.03(4)F.实验结果为烯酮亚胺的重排反应这一化学理论提供了有力的证据.关键词烯酮亚胺;重排反应;晶体结构中图分类号0621.3文献标识码A文章编号1672-4321(2019)03-0357-05DOI10.12130/znmdzk.20190307引用格式吴滨，范詰，王吉庆，等.一种a,0不饱和竣酸亚胺酯的合成、表征与晶体结构［J］.中南民族大学学报(自然科学版),2019,38(3)：357-361.WU Bin,FAN Zhe,WANG Jiqing,et al.Synthetic characterization and crystal structure of a ketenimine rearrangement products［J］.Journal of South-Central University for Nationalities(Natural Science Edition),2019,38(3)：357-361.Synthetic characterization and crystal structure of aketenimine rearrangement productsWU Bin,FAN Zhe,WANG Jiqing,YANG Jinming(School of Pharmaceutical Sciences,South-Central University for Nationalities,Wuhan430074,China)Abstract The synthesis of an a,P-unsaturated carboximidate via a rearrangement reaction of ketenimine was reported.The compound was characterized by1H NMR and single crystal X-ray diffraction.X-ray diffraction analysis of single crystal shows that the compound belongs to the triclinic crystal system and is crystallized in space group P-1,cell parameters:a=7.9832(2)A,6=8.3409(2)A,c=14.5288(4)A,a=81.1650(10)°,/3=74.4740(10)0,y=63.9960(10)°,7=837.03(4)A3.It provides strong evidence for the chemical theory of rearrangement chemistry of ketenimine.Keywords1,2,3-triazoles；ketenimines；rearrangement chemistry；crystal structureCuAAC(Copper-Catalyzed Azide-Alkyne Cycload dition)反应,是指在Cu⑴催化剂存在的条件下,叠氮化物与末端烘桂通过分步反应发生1,3-环加成反应生成1,4-二取代-1,2,3-三氮哩的反应⑴.该反应以其温和的反应条件、优异的收率和普适性引起了广泛的关注⑵.1,4-二取代-1,2,3-=氮哩因其独特的化学结构也成了金属有机化学家们的一个热点研究领域•通常，在过渡金属铐(II)的催化作用下, 1,4-二取代-1,2,3-三氮哩极易失去一分子氮生成a-亚胺基铐卡宾,从而有效地替代危险的重氮试剂.这种独特的反应模式使其成为一种非常稳定、安全的铐卡宾前体卩⑷.三氮哩产生a-亚胺基链卡宾后参与的反应非常丰富，多个课题组相继报道了该活性中间体与烯燈"句、块燈刀、醛和亚胺剧、a,0-不饱和醛⑼、联烯少］、异氤酸酯和异硫氤酸酯⑴］、以及1, 3-二烯①］的环加成反应，合成多种类型的杂环化合物•施敏小组报道了链(II)催化官能团化的1,2,3-三氮哩类底物合成氮桥苯并二氧环庚烷衍生物［闵，收稿日期2019-06-12*通信作者杨金明，研究方向:有机合成,E-mail：jmyang@作者简介吴滨(1973-)，男，教授，博士，研究方向:有机合成,E-mail：2015084@基金项目国家自然科学基金资助项目(21772236)；中央高校基本科研业务费专项资金资助项目(CZT18012)358中南民族大学学报（自然科学版）第38卷1,2-二氢异座咻和1-苗酮类化合物M ,3-亚甲基-2,3-二氢苯并咲喃和3-亚甲基-2,3-二氢阿嗥类化合物［⑸.几乎同时，利用相同的底物，仅仅改变反应条 件，在体系中加入醇或者水作为亲核试剂,杨震课题 组少］报道了二氢异苯并咲喃和苗酮类化合物的合 成•最近,李传莹小组M 报道了铐（II ）催化1,2,3-三氮哩与乙烯基瞇化合物串联合成了系列哌腱衍生物.从简单化合物合成具有结构多样性的复杂分子一直是有机合成领域的一个挑战问题，围绕click 化 学发展多组分串联反应为此问题提供了一个强有力的策略•近年发现,在一些烘烧化合物中,铜催化产生环加成中间过渡态后会脱去一分子氮生成烯酮亚胺的结构,烯酮亚胺中间体会进一步接受亲核试剂进攻,发生重排反应,得到a ,0-不饱和亚胺化合物.Punniyamurthy 小组购报道了一价铜催化烘醛，苯酚以及磺酰叠氮在温和条件下一步合成芳基甲基醵类香豆素衍生物，并提出了可能的机理.在一价铜的催化下,烘桂与磺酰叠氮发生［3 + 2］环加成生成 中间体A, A 失去一份子氮并再生一价铜催化剂后产生烯酮亚胺中间体B ［19］，氧上的孤对电子进攻中间体B,可能通过四元环两性离子过渡态C 进行拟 态周环的［1,3］-迁移重排⑵如，从而得到中间体D,再与苯氧基负离子发生1,4共辄加成反应和瓮醛缩合反应最终得到目标化合物（图1） •O『N 、ySC )2R + ArOHCu(l), base TBAIArOH baseTBAI图1 Pimniyamurthy 小组提出的烯酮亚胺重排可能机制Fig.l Possible mechanism of ketimide rearrangement proposed by Punniyamurthy groupD为了进一步验证并完善该反应机理,设计通过 水杨酸甲酯la 为原料合成底物2a,再通过CuAAC 反应合成目标化合物3a.结果除了以21%的分离收 率得到目标化合物3a 之外,还意外得到了 41%的主产物3b.核磁谱图及高分辨质谱对化合物3b 的结构进行了初步表征解析,并进一步通过X-射线单晶衍射确定了化合物3b 的结构（图2和3）.图2化合物2a 、3a 以及3b 的合成Fig.2 Synthesis of 2a,3a and 3bOMe3b, 41%yield第3期吴滨，等:一种a,卩不饱和竣酸亚胺酯的合成、表征与晶体结构3591实验部分1.1仪器与试剂'H NMR在Bruker AM-600上测定，氛代试剂为Cambrige生产,TMS作为内标物，化学位移单位为ppm.HRMS在Agilent6200Q-TOF上测定.X-射线单晶衍射通过BRUKER D8QUEST测定.水杨酸甲酯、烘丙基漠以及对甲苯磺酰叠氮等试剂从Alfa Aesar、韶远、安耐吉、阿拉丁、TCI、柏卡等公司购买.除甲苯进行了回流重蒸除水(Call?)，其他试剂使用前未经任何处理.1.2化合物2a的合成称取水杨酸甲酯(30mmol,3.9mL)和碳酸钾(60mmol,8.30g)于50mL圆底烧瓶中，加入20 mL N,N-二甲基甲酰胺(DMF)溶解，室温下搅拌，将烘丙基漠(36mmol,3.1mL)缓慢滴加进烧瓶中，搅拌过夜•加入200mL水溶液淬灭反应，加入乙酸乙酯萃取3次，然后合并有机相,用饱和食盐水水洗有机相,再用无水硫酸钠干燥有机相,减压浓缩,通过柱层析进行粗分离纯化(石油矽乙酸乙酯=10/1)得浅黄色油状液体2a6.1g.2a为已知化合物NMR数据与文献报道炉］的一致.1.3化合物3a,3b的合成与3b的表征在N?氛围下，将2a(5mmol,957mg)与CuTC (0.1mmol,19mg)加到50mL圆底烧瓶中,加入干燥的甲苯(15mL),随后边搅拌边缓慢滴加对甲苯磺酰叠氮(5mmol,1.1mL),室温下搅拌过夜.反应结束后，将溶液通过硅藻土过滤，乙酸乙酯冲洗，减压旋干浓缩，柱层析分离(石油醯/乙酸乙酯=5/ 1),得浅黄色固体442mg3a,产率23%,白色固体741mg3b,产率41%.化合物3a」H NMR(600MH z,CDC13)88.33 (s,lH),8.01(d,J=&4Hz,2H),7.85(dd,_7= 7.7,1.8Hz,lH),7.47(ddd,J=8.4,7.4,1.8Hz, lH),7.41-7.36(m,2H),7.08-7.02(m,2H),5.29 (s,2H),3.91(s,3H),2.45(s,3H).13C NMR(151 MHz,CDC13)8166.34,157.56,147.56,144.44,133.87,132.97,132.08,130.58,128.87,122.90, 121.55,120.71,114.16,63.23,52.22,21.98.化合物3b.iH NMR(600MH z,CDC13)87.97 (ddj=7.8,1.7Hz,lH),7.56(d,J=8.3Hz,2H), 7.53(td,J=7.9,1.7Hz,lH),7.35(q,lH),7.30 (tdJ=7.7,1.0Hz,lH),7.17(d J=&1Hz,2H), 7.10(ddj=&1,0.9Hz,lH),6.68(dd,J=17.0, 1.0Hz,lH),6.16(ddj=10.9,1.0Hz,lH),3.69 (s,3H),2.36(s,3H).13C NMR(151MH z,CDC13) 8166.18,164.79,151.07,143.35,138.42,134.02, 132.64,131.95,129.32,126.70,126.49,125.38, 123.46,123.20,52.39,21.63.HRMS calcd for[C18 H17NO5S]requires359.0827,found360.0892[M++ H]；382.0712[M++Na].单晶培养:取50mg3b溶解于少量二氯甲烷中，加入正己烷和正戊烷的混合溶剂后于室温下静置1 d,得到无色块状晶体.1.4晶体结构测定配合物的单晶结构数据在BRUKER D8 QUEST,BrukerShekTL软件包解析和优化该结构,多扫描方法(SADABS)对吸收效应进行数据校正,晶体结构用直接法求解,所有非氢原子使用全矩阵最小二乘法对F2进行各项异性修正,用理论加氢法对氢原子进行加和至理论位置.2结果与讨论2.1晶体结构鉴定和描述化合物3b(C18H17NO5S)的晶体数据和有关数据收集及结构精修数据列于表1,相关键长和键角数据列于表2.晶体编号:JM1-29-1.化合物3b的晶体结构如图3所示,是一种无色块状晶体，属三斜晶系,P-1空间群，相对分子量M=359.38,近似尺寸为0.160mm X0.337mmX0.410mm.X-ray晶体分析表明，晶胞参数a=7.9832(2)A,6=8.3409(2)k,c= 14.5288(4)A,a=81.1650(10)°,0=74.4740(10)°, y=63.9960(10)°,V=837.03(4)A3.360中南民族大学学报（自然科学版）第38卷表1化合物3b的晶体数据和结构精修数据Tab.l Crystal data and structure refinement for compound3b晶体参数晶体数据Chemical fbnnula C18H17NO5SFormula weight359.38g/molTemperature150(2)KWavelength 1.54178ACrystal size0.160x0.337x0.410mmCrystal habit light colourless BLOCKCrystal system triclinicSpace group P-1Unit cell dimensions a=7.9832(2)A a=81.1650(10)°Volume 几&3409(2)A j8=74.4740(10)°c=14.5288(4)A y=63.9960(10)°837.03(4)A3Z2Density(calculated) 1.426g/cm3Absorption coefficient 1.981mm-1F(000)376Theta range for data collection 3.16to79.24°Index ranges—10W h W10,-9W k W10,-18W I W18 Data/restraints/parameters3580/0/228Final R indices3543data；I>2cr(I)R1=0.0318,wR2=0.0859Weighting scheme Largest diff.peak and hole all data R1=0.0321,wR2=0.0862 w=l/[ct2(F qz)+(0.0455P)2+0.3479P] Where P=(F02+2F c2)/30.355and-0.471eA~3R.M.S.deviation from mean0.046eA~3表2是烯酮亚胺重排区域的相关键长键角.因为晶体结构C1-C2-C3-C4-C5-C12-C11,包括O4-S1-03区域是对甲苯磺酰基,C7-C16-C15-C14-C13-C8和05-C9-02-C10这部分对应水杨酸甲酯区域.根据晶体结构.C17-C18的碳碳双键与C6-N1的碳氮双键是处于反式共辄构型，因而能得到热力学稳定的3b.这为Punniyamurthy[6]小组提出的伪周环四元环状过渡态机理猜想提供了有力的证据，同时他们提出的机理中化合物D的画法是顺式共辄的构型，经过本实验的单晶验证,可以修正为反式共辄画法，这样更为严谨（图3）.表2配合物1的有关键角和键长数据Tab.2Selected bond lengths and angles for compound1图3化合物3b的晶体结构图Fig.3Molecular structure of compound3b 3结语键型键长/A键角类型键角/e O(l)-C(6) 1.3448(14)C(6)-O(l)-C(7)117.85(9) 0(l)-C(7) 1.4077(14)C(6)-N(1)-S1)126.83(9) N(l)-C(6) 1.2832(16)O(l)-C(6)-C(17)112.15(10) N(l)-S(l) 1.6366(10)N(l)-C(6)-O(l)117.78(10) C(6)-C(17) 1.4701(16)N(l)-C(6)-C(17)130.06(11) C(17)-C(18) 1.3144(19)C(6)-C(17)-C(18)122.10(12)使用CuAAC反应条件与设计的底物反应，意外合成出了化合物3b,通过中NMR、HRMS以及X-射线单晶衍射证实了化合物3b的确切结构.首次报道了烯酮亚胺发生迁移重排反应后的产物的单晶结构,为烯酮亚胺的重排化学提供了有力的证据,并为烯酮亚胺作为有机反应活性中间体发展更多有机合第3期吴滨，等:一种a,卩不饱和竣酸亚胺酯的合成、表征与晶体结构361成方法学提供了理论依据，基于烯酮亚胺为中间体的新型有机合成方法学的开发正在进一步探索中.参考文献[1]ROSTOVTSEV V V,GREEN L G,FOKIN V V,et al.Astepwise huisgen cycloaddition process:copper(I)catalyzedregioselective"ligation”of azides and tenrnnal alkynes[J].Angew Chem Int Ed,2002,41(14):2596-2599.[2]DAVIES H M L,ALFORD J S.Reactions of metallocarbenesderived from TV-sulfbnyl-1,2,3-triazoles[J].Chem Soc Rev,2014,43：5151-5162.[3]CHATTOPADHYAY B,GEVORGYAN V.Transition metalcatalyzed denitrogenative transannulation:Convertingtriazoles into other heterocyclic systems[J].Angew Chem IntEd,2012,51：862-872.[4]GULEVICH A V,GEVORGYAN V.Versatile reactivity ofrhodium-iminocarbenes derived from TV-sulfonyl triazoles[J].Angew Chem Int Ed,2013,52：1371-1373.[5]HOR1NEFF T,CHUPRAKOV S,CHERNYAK N,et al.Rhodium-catalyzed transannulation of1,2,3-triazoles withnitriles[J]J Am Chem Soc,2008,130：14972-14974.[6]CHUPRAKOV S,KW0K S W,ZHANG L,et al.Rhodium-catalyzed enantioselective cyclopropanation of olefins with N-suLfonyl1,2,3-triazoles[J].J Am Chem Soc,2009,131:18034-18035.[7]CHATTOPADHYAY B,GEVORGYAN V.Rh-catalyzedtransannulation of7V-tosyl-l,2,3-triazoles with terminalalkynes[J].Org Lett,2011,13：3746-3749.[8]ZIBINSKY M,FOKIN V V.Sulfonyl-1,2,3-triazoles：Convenient synthones for heterocyclic compounds[J].AngewChem Int Ed,2013,52：1507-1510.[9]MIURA T,TANAKA T,HIRAGA K,et al.Stereoselectivesynthesis of2,3-dihydropyrroles from terminal alkynes,azides,and a,p-unsaturated aldehydes via7V-sulfonyl-1,2,3-triazoles[J].J Am Chem Soc,2013,135：13652-13655. [10]SCHULTZ E E,SARPONG R.Application of in situ-generated Rh-bound trimethylenemethane variants to thesynthesis of3,4-fused pyrroles[J].J Am Chem Soc,2013,135：4696-4699.[11]CHUPRAKOV S,KW0K S W,FOKIN V V.Transannulationof1-sulfonyl-1,2,3-tria^oles with heterocumulenes[J].JAm Chem Soc,2013,135：4652-4655.[12]SHANG H,WANG Y,TIAN Y,et al.The divergent synthesisof nitrogen heterocycles by rhodium(H)-catalyzedcycloadditions of1-sulfonyl1,2,3-triazoles with1,3-dienes[J].Angew Chem Int Ed,2014,53：5662-5666.[13]ZHANG Y S,TANG X Y,SHI M.Unprecedented synthesisof aza-bridged benzodioxepine derivatives through a tandemRh(II)-catalyzed1,3-rearrangement/[3+2]cycloadditionof carbonyltriazoles[J].Chemical Communications,2014,50(100)：15971-15974.[14]SUN R,JIANG Y,TANG XY,et al.Rhodium(II)-catalyzedand thermally induced intramolecular migration of N-sulfonyl-1,2,3-triazoles:New approaches to1,2-dihydroisoquinolines and1-indanones[J].Chemistry-AEuropean Journal,2015,22(16):5727-5733.[15]TANG X Y,ZHANG Y S,HE L,et al.Intramolecularannulation of aromatic rings with TV-sulfonyl1,2,3-triazoles：divergent synthesis of3-methylene-2,3-dihydrobenzofuransand3-methylene-2,3-dihydroindoles[J].ChemicalCommunications,2015,51(101):133-136.[16]SHEN H,FU J,GONG J,et al.Tunable and chemoselectivesyntheses of dihydroisobenzofurans and indanones viarhodium-catalyzed tandem reactions of2-triazole­benzaldehydes and2-triazole-alkylaryl ketones[J].OrgLett,2014,16(21):5588-5591.[17]YU S,AN Y,WANG W,et al.Synthesis of piperidinederivatives by rhodium-catalyzed tandem reaction of N-sulfonyl-1,2,3-triazole and vinyl ether[J].AdvancedSynthesis&Catalysis,2018,360(ll):2125-2130.[18]MURUGAVEL G,PUNNIYAMURTHY T.Novel copper-catalyzed multicomponent cascade synthesis ofiminocoumarin aryl methyl ethers[J].Org lett,2013,15(15)：3828-3831.[19]LU P,WANG Y.The thriving chemistry of ketenimines[J].Chem Soc Rev,2012,41(17):5687-5705.[20]NGUYEN M T,LANDUYT L,NGUYEN H M T.1,3・Sigmatropic shifts in carbonylketenes,carbonyl isocyanatesand analogous confounds[J].Eur J Org Chem,1999：401-407.[21]FINNERTY J J,WENTRUP C.Facile ketene-ketene andketene-ketenimine rearrangements:A study of the1,3-migration of a-substituents interconverting a-imidoylketenesand a-oxoketenimines,a pseudopericyclic reaction[J].J orgchem,2004,69(6):1909-1918.[22]LYKAKIS I N,EFE C,GRYPARIS C,et al.Ph3PAuNTf2asa superior catalyst for the selective synthesis of2H-chromenes:Application to the concise synthesis ofbenzopyran natural products[J].Eur J Org Chem,2011：2334-2338.（责任编辑姚春娜）。

Synthesis and characterization ofmetal complexesIntroductionMetal complexes have been actively studied due to their potential applications in various fields such as catalysts, materials, and medicine. The synthesis and characterization of metal complexes are fundamental steps towards understanding their properties and behaviors. In this article, we will discuss some of the methods and techniques used for synthesizing and characterizing metal complexes, as well as their applications.Synthesis of metal complexesThe synthesis of metal complexes can be achieved through various methods such as salt metathesis, ligand exchange, and coordination polymerization. Salt metathesis involves replacing one metal ion in a salt with another metal ion. Ligand exchange involves replacing one ligand in a metal complex with another ligand. Coordination polymerization involves the combination of metal ions and organic ligands to form a three-dimensional network structure.One example of a metal complex synthesis method is ligand exchange. In this method, a metal complex with a specific ligand is reacted with a new ligand to form a different metal complex. For example, the reaction between copper(II) sulfate and sodium acetate results in the formation of copper(II) acetate.CuSO4 + 2NaOAc → Cu(OAc)2 + Na2SO4Another example is coordination polymerization. In this method, metal ions and organic ligands are combined in a solution to form a solid network structure. For example, the reaction between zinc(II) nitrate and 2,6-naphthalenedicarboxylic acid results in the formation of a porous coordination polymer called MOF-5.Zn(NO3)2 + H2bdc → Zn4O(H2bdc)3 + 2HNO3Characterization of metal complexesCharacterization of metal complexes is important in understanding their physical and chemical properties. Techniques such as X-ray crystallography, infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy can be used to identify the structure and composition of metal complexes.X-ray crystallography involves the analysis of crystals using X-rays to determine the positions of atoms in a molecule. It provides information on the three-dimensional structure of a metal complex. Infrared spectroscopy involves the measurement of the energy absorbed by a molecule due to vibrations of its chemical bonds. It provides information on the functional groups present in a metal complex. NMR spectroscopy involves the measurement of the absorption of energy by nuclei in an external magnetic field. It provides information on the electronic environment surrounding metal ions in a complex.Applications of metal complexesMetal complexes have a wide range of applications in various fields. They can act as catalysts in chemical reactions, for example, the use of palladium complexes as catalysts in Suzuki coupling reactions. They can also be used as materials in the form of coordination polymers for gas storage or catalysis. In medicine, metal complexes can be used as contrast agents in imaging techniques or as anticancer drugs.ConclusionIn summary, the synthesis and characterization of metal complexes are important for understanding their properties and behavior. Various methods and techniques can be used for synthesizing and characterizing metal complexes. Applications for metal complexes are diverse and extend to fields such as catalysis, materials, and medicine. With continued research and development, metal complexes are expected to play an increasingly important role in these fields.。

Synthesis and Characterization of Novel Thermoplastic Polyester Containing Blocks of Poly[(R)-3-hydroxyoctanoate]andPoly[(R)-3-hydroxybutyrate]Austin P.Andrade,Bernard Witholt,Dongliang Chang,and Zhi Li*Institute of Biotechnology,ETH-Zu¨rich,Ho¨nggerberg,CH-8093Zu¨rich,SwitzerlandReceived August8,2003;Revised Manuscript Received October17,2003ABSTRACT:Novel block copolyester containing biocompatible and biodegradable biopolyester blocks was prepared by polycondensation of telechelic hydroxylated poly[(R)-3-hydroxyoctanoate](PHO-diol)and telechelic hydroxylated poly[(R)-3-hydroxybutyrate](PHB-diol)with terephthaloyl chloride(TeCl).Reaction of PHO-diol(M p of2100),PHB-diol(M p of3200),and TeCl at a ratio of1.3:1:2.1gave the block co-polyester PHOHBTe in86%yield with a molecular weight M p of7200(GPC).The chemical structure of the copolyester was confirmed by1H-,13C-,and COSY-NMR and IR spectra.On average,2PHO-diol,1PHB-diol,and2TeCl were incorporated in each molecule of the block copolyester PHOHBTe.For comparison, polyester PHOTe with a M p of7100(GPC)was prepared in81%yield by reaction of PHO-diol and terephthaloyl chloride at a molar ratio of1:1.2.NMR analysis suggested that PHOTe contains3PHO and3Te units on average.While PHOTe containing no PHB block is soft-sticky,PHOHBTe containing both soft PHO and hard PHB blocks showed good thermoplastic properties with T m of129and140°C and a T g of-41°C.Thus,for the first time,block copolyester containing PHO and PHB blocks has been prepared and demonstrated to be thermoplastic.IntroductionThe microbial poly[(R)-3-hydroxyalkanoates](PHAs) are potentially very useful materials due to their biodegradability and biocompatibility.Their thermal properties are,however,rather poor:poly[(R)-3-hy-droxybutyrate](PHB)is crystalline-brittle with a melt-ing temperature(T m)of175°C and a glass transition temperature(T g)of0-4°C;1-4mcl-PHAs(which contain medium chain length alkanoate monomers)are weakly crystalline and soft-sticky with T m between39and61°C and T g between-25and-44°C.5-10A way to improve the thermoplastic properties of PHAs is to make a copolyester.Biosyntheses of random copolyes-ters such as poly[(R)-3-hydroxybutyrate-co-(R)-3-hy-droxyvalerate],P(3HB-co-3HV),2,11-13and poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyalkanoate],P(3HB-co-3HA),14-17are known.Among them,P(94%3HB-co-6%3HA)consisting of94%monomers of(R)-3-hydroxy-butyrate(3HB)and6%monomers of(R)-3-hydroxy-alkanoates(3HA)containing6-12carbon atoms showed interesting thermoplastic properties with a T g of-8°C and T m of133and146°C.16We are interested in chemical preparation of block copolyesters from PHAs for desired thermal and me-chanical properties.Recently,we transformed mcl-PHAs into enantiomerically pure telechelic hydroxylated mcl-PHAs(mcl-PHA-diols)with low molecular weight,low T m,and low T g.18The easily available telechelic hy-droxylated poly[(R)-3-hydroxyoctanoate](PHO-diol)was demonstrated to be an excellent soft segment for co-polymerization.19On the other hand,telechelic hydrox-ylated poly[(R)-3-hydroxybutyrate](PHB-diol)20was shown to be a useful hard segment.21,19Thus,it might be possible to prepare block copolyesters with good thermoplastic properties by incorporating the soft PHO-diol and the hard PHB-diol into the polymer.Moreover,the polymer properties might be designed and then achieved by changing the ratio of the soft and hard segments.Here,we report the first synthesis of block co-polyesters containing PHO and PHB blocks by po-lymerization of the soft segment PHO-diol and the hard segment PHB-diol with terephthaloyl chloride,the analysis of the polymer structures,and the character-ization of the physical properties.Experimental SectionMaterials.Telechelic hydroxylated poly[(R)-3-hydroxyoc-tanoate]containing C8and C6monomers in a ratio of90:10 [PHO-diol,M n)2400(VPO),M p)2100(GPC)]18and telechelic hydroxylated poly[(R)-3-hydroxybutyrate][PHB-diol, M n)2600(VPO),M p)3200(GPC)]20were prepared according to the published procedures and predried by azeotropic distil-lation with1,2-dichloroethane.All reagents and solvents were purchased from Fluka with p.a.quality:terephthaloyl chloride was dried under high vacuum at room temperature for2days before use;pyridine,toluene,and chloroform were dried with activated molecular sieve A4(pore size4Å).Synthesis of Block Copolyester PHOHBTe.Toluene(40 mL)and pyridine(20mL)were added to a mixture of telechelic hydroxylated poly[(R)-3-hydroxyoctanoate](PHO-diol)(1.205 g,0.502mmol,M n)2400,M p)2100),telechelic hydroxylated poly[(R)-3-hydroxybutyrate](PHB-diol)(1.01g,0.388mmol, M n)2600,M p)3200),and terephthaloyl chloride(0.164g, 0.808mmol)in a250mL flask under a nitrogen atmosphere. The stirred mixture was heated progressively to80°C to dissolve the reactants and then to105°C for polycondensation. The reaction was stopped after12h by cooling,and the solvent was evaporated.The product was treated four times with chloroform/water1:4(v/v),and the organic phase was separ-ated and then washed vigorously three times with aqueous HCl(0.1M)to remove pyridine and the possible unreacted terephthaloyl chloride.The collected organic phase was dried over Na2SO4and filtered,and the solvent was evaporated. Drying under high vacuum at80°C gave2.01g(86%)of the block copolyester PHOHBT with an M p of7200(measured by GPC).*Corresponding author:Tel+4116333811;Fax+4116331051;e-mail zhi@biotech.biol.ethz.ch.9830Macromolecules2003,36,9830-983510.1021/ma035164p CCC:$25.00©2003American Chemical SocietyPublished on Web11/26/2003Synthesis of Interchange Polyester PHOTe.Similar to the procedure described for PHOHBTe,reaction of PHO-diol (1.023g,0.426mmol,M n )2400,M p )2100)and terephthaloyl chloride (0.102g,0.502mmol)in a mixture of toluene (40mL),chloroform (5.0mL),and pyridine (5.0mL)at 105°C for 30h afforded 0.90g (81%)of PHOTe with an M p of 7100(measured by GPC).Characterization Techniques.1H and 13C NMR spectra were measured on a Bruker DRX-300(300MHz)at 293K in CDCl 3.COSY (1H,13C)and COSY (1H,1H)were measured on a Bruker DRX-400(400MHz)at 300K in CDCl 3.Chemical shifts are given in ppm relative to tetramethylsilane.IR spectra (film)were recorded on a Bruker Vector 22spectrom-eter at room temperature.The molecular weight distribution was determined by gel permeation chromatography (GPC)in THF at room temperature with a Knauer chromatograph equipped with a differential refractive index detector with two PLGel mixed 5µm columns (7.5mm ×600mm)at 85bar and at 45°C.M p was estimated from the retention volume based on polystyrene standards.T m and T g were obtained by dif-ferential scanning calorimetry (DSC)with a Mettler-DSC 30instrument equipped with Me-70329cooler and a Tc15/TA controller.The samples in a 40µL aluminum carrier were heated in the first scan from -100to 200°C with a heating rate of 10°C/min,cooled from 200to -100°C at a cooling rate of -10°C/min,and then heated for the second scan.Results and DiscussionPoly[(R )-3-hydroxyoctanoate](PHO)is the most promi-nent representative of mcl-PHAs,and it can be produced in large amounts.Transesterification of PHO with ethylene glycol afforded enantiopure telechelic PHO-diol with a M n of 2400(VPO),a M p of 2100(GPC),and a T g of -56°C in excellent yield.18This readily available compound was selected as the soft segment for the preparation of block copolyesters.On the other hand,telechelic diol prepared from poly[(R )-3-hydroxybu-tyrate](PHB-diol)20with a T m of 149°C,a M n of 2600(VPO),and a M p of 3200(GPC)was chosen as the hard segment.Terephthaloyl chloride (TeCl)was used as junction unit.In principle,the ratio of the soft segment,hard segment,and the junction unit can be controlled to prepare the block co-polyesters with desired proper-ties.To demonstrate the concept,PHO-diol,PHB-diol,and TeCl were used in a molar ratio of 1.3:1:2.1to prepare the co-polyester PHOHBTe (Scheme 1).For a comparison,interchange polyester PHOTe containing no PHB block was also synthesized from PHO-diol and TeCl in a molar ratio of 1:1.2.New polyesters were formed by the reaction between the COCl groups of TeCl and the OH groups of the telechelic diols.Since water can stop the polymerization by reacting with TeCl to give the corresponding acid,the reaction was carried out under anhydrous conditions and under a nitrogen atmosphere.PHO-diol and PHB-diol were at first dried by azeotropic distillation with 1,2-dichloroethane and then reacted with TeCl in a mixture of toluene and pyridine at 105°C for 12h.The solvent was removed by evaporation,the residue was treated with water to destroy the possible unreacted TeCl,and the product was extracted into CHCl 3.Sub-sequent treatment of organic phase with 0.1M HCl removed the trace amount of pyridine.Drying under high vacuum at 80°C afforded the block copolyester PHOHBTe in 86%yield.A molecular weight M p of 7200was established by gel permeation chromatography (GPC),shown in Figure 1.Similarly,PHOTe containing only the soft PHO block was prepared in 81%yield by reaction of PHO-diol with TeCl in a molar ratio of 1:1.2at 105°C for 30h.The resulting material has a M p of 7100(GPC),which is similar to that of PHOHBTe (Figure 1).In the IR spectra of PHOBOTe,the two absorption bands of the OH groups of the starting materials PHO-diol and PHB-diol at 3530-3350cm -1decreased sig-nificantly,indicating the successful polymerization.The ester functions were confirmed by the strong absorption at 1735cm -1.Scheme1Macromolecules,Vol.36,No.26,2003Novel Thermoplastic Polyesters 9831The structure of PHOHBTe was confirmed by NMR analyses.The 1H-and COSY (1H,13C)-NMR spectra are given in Figures 2and 3,respectively.On the basis of the COSY (1H,1H)-and COSY (1H,13C)-NMR spectra and comparison with the 1H-NMR spectrum of PHO-diol,the chemical shifts of all protons of PHOHBTe were assigned as shown in Figure 2.The assignment of the13Cchemical shifts is also possible,and the result is summarized in Table 1.Although the PHO block contains C8and C6monomer in a ratio of 90:10,there was no significant difference between the C8and C6monomers in the 1H-NMR spectrum,and the C6mono-mers gave only several additional weak signals in the 13C-NMR spectrum.For simplicity,only theassignmentFigure 1.GPC chromatograms of the block copolyester PHOHBTe,the interchange polyester PHOTe,the hard segment PHB-diol,and the soft segmentPHO-diol.Figure 2.1H-NMR spectrum (300MHz)of the block copolyester PHOHBTe at 293K in CDCl 3.*-OCH 2CH 2O -of bis substituted ethylene glycol in PHO-diol block.9832Andrade et al.Macromolecules,Vol.36,No.26,2003for the C8monomer of the PHO block was given in this work.PHO-diol with M n of 2400contains 16.8HO monomer units (m )on average,while PHB-diol with M n of 2600has the average number of HB monomer units (n )of 29.5.In the 1H-NMR spectrum of PHOHBTe,the intensity of methyl group proton a of the PHO block is 15.05;thus,the intensity of proton i ,o ,and g of the same block should be 15.05×2/3)10.03.While the totalintegration of proton i ,o ,g and t is 19.80,the intensity of proton t from the PHB block should be 19.80-10.03)9.77.The ratio of the PHO and PHB block in PHOHBTe can be therefore deduced as about 2:1(10.03/16.8:9.77/29.5).The aromatic proton u and v of the Te part had an integration of 1.07,which suggested that the ratio of Te junction unit and PHO block is about 1:1(1.07/4:15.05/3/16.8).Although M n of PHOHBTe was not determined,the M p value of 7200for PHOHB suggests that on average it contains 2PHO (M p of 2100)blocks,1PHB (M p of 3200)block,and 2Te junction units.The major terminating groups are the primary and secondary alcohols,which is confirmed by the signals of proton f ,g and p ,q .Similarly,the structure of PHOTe was also confirmed by 1H,13C,COSY (1H,1H),and COSY (1H,13C)-NMR spectra.The chemical shift assignments for the 1H-NMR spectrum are given in Figure parison of the intensities of proton a of PHO and proton u and vofFigure 3.COSY (1H,13C)-NMR spectrum (400MHz)of the block copolyester PHOHBTe at 300K in CDCl 3(shown only 10-130ppm from 13C-NMR).Figure 4.1H-NMR spectrum (300MHz)of the interchange polyester PHOTe at 293K in CDCl 3.(*)-OCH 2CH 2O -of bis-substituted ethylene glycol in PHO-diol block.Table 1.Assignment of Chemical Shifts of PHOHBTe inthe 13C NMR Spectrum position δ(13C)position δ(13C)a 14.0l 71.9b 22.5o 41.8c 24.7p 66.3d 31.5q 60.8e 33.8r 19.8f 68.2s 67.6g 43.3t 40.8h 70.9u,v 129.5,129.7,130.0i 39.1w 133.5,133.8,134.6j 63.1x165.4,165.8,172.0,172.4k62.3C d O (HB,HO)169.2,169.4Macromolecules,Vol.36,No.26,2003Novel Thermoplastic Polyesters 9833the Te part revealed a 1:1ratio of PHO and Te.On the basis of M p of 7100for PHOTe,it can be concluded that on average 3PHO (M p of 2100)blocks and 3Te junction units are incorporated in the interchange polyester PHOTe.The physical properties of the new polymers were characterized by DSC and are listed in Table 2.The interchange polyester PHOTe with only the soft PHO as polyester backbone linked with an aromatic junction unit did not result in a hard polymer:the new polymer is soft-sticky with no T m and a T g of -36°C.On the other hand,the co-polyester PHOHBTe containing PHB and PHO-blocks as hard and soft segments,respectively,showed good thermoplastic properties with a T g of -41°C and T m of 128and 140°C (Figure 5).This T g is probably for the PHO segment,and the T g value of PHB segment was not observed.A second heating for DSC measurement revealed a T c of 60°C.Although the molecular weight is not very high,PHOHBTe represents the first example of block copolyester containing the soft PHO and hard PHB paring with the random copolyester P(3HB-co -3HA)consisting of 94mol %HB and 6mol %HA,16PHOHBTe has similar T m but much lower T g .The molecular weight of the block polymer-could be in principle further increased,for instance,by performing the reaction under argon atmospheres and/or by using other junction units.The existence of the PHB block in such copolyesters is proven to be essential for increasing the melting and mechanic properties.The physical properties of new block copolyester could be designed and achieved by changing the ratio of PHO and PHB blocks.ConclusionsFor the first time,co-polyesters containing biodegrad-able and biocompatible PHO and PHB blocks have been synthesized by use of PHO-diol and PHB-diol as soft and hard segments,respectively.The model polymer PHOHBTe shows good thermoplastic properties,and the physical properties of the block copolyester can be further optimized by incorporation of the PHO and PHB blocks in an appropriate ratio.Acknowledgment.We thank Mr.M.Colussi (ETH-Zu ¨rich)for the determination of GPC and DSC and Mr.P.Zumbrunnen (ETH-Zu ¨rich)for the measure-ment of COSY NMR spectra.The financial support by the Swiss National Science Foundation through the Swiss Priority Programme in Biotechnology is greatly appreciated.Supporting Information Available:13C-,COSY (1H,1H)-,and COSY (1H,13C)-NMR and IR spectra of the block copolyester PHOHBTe;13C-,COSY (1H,1H)-,and COSY (1H,13C)-NMR spectra of the interchange polyester PHOTe.This material is available free of charge via the Internet at .References and Notes(1)Doi,Y.Microbial Polyesters ;VCH Publishers:New York,1990.(2)Hocking,P.J.;Marchessault,R.H.In Chemistry andTechnology of Biodegradable Polymers ;Griffin,G.J.L.,Ed.;Blackie:Glasgow,1994;Chapter 4,p 48.(3)Holmes,P.A.Phys.Technol.1985,16,32.(4)Doi,Y.Macromol.Symp.1995,98,585.Table 2.Physical Properties of PHOHBTe,PHOTe,PHO,PHB,P(3HB-co -3HA),and Polypropylene (PP)properties PHOHBTe PHOTe PHO a PHB b P(3HB-co -3HA)cPP d M w (GPC)660005390001391500700000M n (GPC)2360015400060500060000M p (GPC)72007100M w /M n (GPC) 1.6 2.1 2.8 3.5 2.35-12T g (°C,DSC)-41-36-304-8-10T m (°C,DSC)129,14061180133,146176a Data from ref 19.b Data from ref 22.c Biosynthetic copolyester consisting of 94mol %3HB and 6mol %3HA;data from ref 16.dData from ref1.Figure 5.DSC spectrum of the block copolyester PHOHBTe.9834Andrade et al.Macromolecules,Vol.36,No.26,2003(5)Morin,F.G.;Marchessault,R.H.Macromolecules1992,25,576-581.(6)Marchessault,R.H.;Monasterios, C.J.;Morin, F.G.;Sundararajan,P.R.Int.J.Biol.Macromol.1990,12,158-165.(7)Witholt,B.;Kessler,B.Curr.Opin.Biotechnol.1999,10,279-285.(8)Preusting,H.;Nijenhuis, A.;Witholt, B.Macromolecules1990,23,4220-4224.(9)Gross,R.A.;DeMello,C.;Lenz,R.W.;Brandl,H.;Fuller,R.C.Macromolecules1989,22,1106-1115.(10)Kato,M.;Fukui,T.;Doi Y.Bull.Chem.Soc.Jpn.1996,69,515-520.(11)Doi,Y.;Tamaki,A.;Kunioka,M.;Nakamura,Y.;Soga,K.Appl.Microbiol.Biotechnol.1988,28,330-334.(12)Kamiya,N.;Yamamoto,Y.;Inoue,Y.;Chujo,R.;Doi,Y.Macromolecules1989,22,1676-1682.(13)Mitomo,H.;Morishita,N.;Doi,Y.Macromolecules1993,26,5809-5811.(14)Shimamura,E.;Kasuya,K.;Kobayashi,G.;Shiotani,T.;Shima,Y.;Doi,Y.Macromolecules1994,27,878-880. (15)Doi,Y.;Kitamura,S.;Abe,H.Macromolecules1995,28,4822-4828.(16)Matsusaki,H.;Abe,H.;Doi,Y.Biomacromolecules2000,1,17-22.(17)Watanabe,T.;He,Y.;Fukuchi,T.;Inoue,Y.Macromol.Biosci.2001,1,75-83.(18)Andrade, A.P.;Witholt, B.;Hany,R.;Egli,T.;Li,Z.Macromolecules2002,35,684-689.(19)Andrade,A.P.;Neuenschwander,P.;Hany,R.;Egli,T.;Witholt,B.;Li,Z.Macromolecules2002,35,4946-4950. (20)Hirt,T.D.;Neuenschwander,P.;Suter,U.W.Macromol.Chem.Phys.1996,197,1609-1614.(21)Hirt,T.D.;Neuenschwander,P.;Suter,U.W.Macromol.Chem.Phys.1996,197,4253-4268.(22)Abe,H.;Doi,Y.;Kumagai,Y.Macromolecules1994,27,6012-6017.MA035164PMacromolecules,Vol.36,No.26,2003Novel Thermoplastic Polyesters9835。

Synthesis and characterization of near-infrared fluorescent and magnetic iron zero-valent nanoparticlesNagore Pérez a ,Leire Ruiz-Rubio a ,*,JoséLuis Vilas a ,b ,Matilde Rodríguez a ,Virginia Martinez-Martinez a ,Luis M.León a ,baDepartamento de Química Física,Facultad de Ciencia y Tecnología,Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU),Apdo 644,Bilbao 48080,Spain bBasque Center for Materials,Applications and Nanoestructures (BCMATERIALS)Parque Tecnológico de Bizkaia,Ed 500,Derio 48160,SpainA R T I C L E I N F OArticle history:Received 4May 2015Received in revised form 4September 2015Accepted 6September 2015Available online 9September 2015Keywords:Iron zero valent nanoparticles Fluorescent MagneticPolyethylenglycolA B S T R A C TPolyethylene glycol coated iron nanoparticles were synthesized by a microemulsion method,modi fied and functionalized.The polymer coating has a crucial role,preventing the iron oxidation and allowing the functionalization of the particles.The nanoparticles were characterized and their magnetic properties studied.A photochemical study of the iron nanoparticles conjugated with a near-infrared fluorescent dye,Alexa Fluor 660,con firmed that the fluorescent dye is attached to the nanoparticles and retains its fluorescent properties.The bioimages in red and near-infrared (NIR)region are favourable due to its minimum photodamage and deep tissue penetration.The nanoparticles obtained in this study present a good magnetic and fluorescent properties being of particular importance for potential applications in bioscience.ã2015Elsevier B.V.All rights reserved.1.IntroductionA broad range of nanosized inorganic particles,including magnetic nanoparticles and quantum dots,have been extensively investigated because of their unique optical,electrical and magnetic properties [1–5].Moreover,magnetic iron oxide colloids have been successfully used as magnetic resonance imaging (MRI)contrast agents and for cancer hyperthermia therapy [6–9].The shape,size and size distribution of the magnetic materials are the key factors in determining their chemical and physical properties.Thus,the development of size and shape-controlled magnetic materials is crucial for their application [3,9].So far,the most widely used and studied magnetic material is iron oxide,in the form of magnetite (Fe 3O 4)and maghemite (g -Fe 2O 3).Elemental iron has a signi ficantly higher magnetic moment than its oxides.Moreover,elemental iron is the most useful among the ferromagnetic elements;it has the highest magnetic moment at room temperature (218emu g À1in bulk),and a Curie temperature which is high enough for the majority of practical applications.However,obtaining Fe nanoparticles,relatively free of oxide (usually Fe 3O 4),is still a challenge,to a large extent,not overcome [10–13].Besides the properties of the metallic core,the coating of the nanoparticles could determinate or improve the uses of this kind of materials.For example,functionalized magnetic nanoparticles have been employed for site-speci fic drug delivery [14]or treatment waterwaste [15,16].The variety of potential coating materials is continuously increasing with the development of new polymeric materials.However,polyethylene glycol (PEG)could be considered one of the most suitable polymer coatings for nanoparticles designed to be used in biomedicine.PEG is a water-soluble polymer with a low toxicity and antibiofouling properties that make it an appropriate candidate for several bioscience related applications [17,18].PEG chains attached to a nanoparticle surface exhibit a rapid chain motion,this could contribute to the good physiological properties of the PEGylated nanoparticles [19]for imagining and therapy application.Also,successful studies haven been devoted to PEG-PLA coated nano-particles for drug delivery [20,21].PEG grafted onto the surface of nanoparticles provides steric stabilization that competes with the destabilizing effects of Van der Waals and magnetic attraction energies.Thus,there is a growing demand for improved methods for the synthesis and characterization of polyethylene glycol (PEG)derivatives [22–25].Especially,polyethylene glycols (PEGs)of long polymeric chains have found signi ficant applications in the structure stabilization [26–28].Finally,the polymeric coatings of the nanoparticles could be conjugated with antibodies or fluorescent dyes adding different*Corresponding author.E-mail address:leire.ruiz@ehu.eus (L.Ruiz-Rubio)./10.1016/j.jphotochem.2015.09.0041010-6030/ã2015Elsevier B.V.All rights reserved.Journal of Photochemistry and Photobiology A:Chemistry 315(2016)1–7Contents lists available at ScienceDirectJournal of Photochemistry and Photobiology A:Chemistryj o u rn a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /j p h o t o c h emproperties to the system[29–31].That is,fluorescent-magnetic nanoparticles could be designed as an all-in-one diagnostic and therapeutic tool,able to visualize and simultaneously treat various diseases.Fluorescence imaging is one of the most powerful techniques for monitoring biomolecules in living pared with fluorescent imaging in the visible region,biological imaging in red and near-infrared(NIR)region is favourable due to its minimum photodamage,deep tissue penetration,and minimum background autofluorescence caused by biomolecules in living systems. Therefore,chromophores with emission in red or near-infrared region have been paid increasing attention in recent years[32,33].However,there is a specific difficulty in the preparation of fluorescent magnetic nanoparticles due to the risk of quenching of thefluorophore on the particle surface by the magnetic core.This problem could be solved by coating the magnetic core with a stable isolating shell prior to the introduction of thefluorescent molecule or by attaching an appropriate spacer to thefluorophore.Most fluorescent magnetic nanoparticles thus have a core-shell struc-ture.Several studies have been devoted to develop iron oxide nanoparticles conjugated withfluorescent dyes,in order to obtain dual-responsive nanoparticles,with magnetic andfluorescent response[31].Often,the methods are time consuming due to the many synthetic steps or the fact that gold or silica precoating is required to protect the iron oxide nanoparticles previous to their functionalization[34–36].Also,there is a significant lack on studies about iron nanoparticles functionalized withfluorophores [37].The aim of this work is to synthesize iron nanoparticles coated with a PEG-derivative and functionalized with afluorescent dye.The iron core of the nanoparticles will provide higher magnetization saturation than iron oxides,the PEG not only protects the metallic core but also adds interesting properties to biologically related applications.The selectedfluorescent dye, imaging in red and near-infrared,is highly adequate for an application in medicine owing to its low photodamage.So,the obtained nanoparticles could be highly promising materials for combined MR/Optical imaging applications.2.Materials and methods2.1.ChemicalsAll chemicals were reagent grade and used without purification. Ferrous chloride tetrahydrate(FeCl2Á4H2O),sodium borohydride (NaBH4)and cyclohexan solvent were purchased from Sigma–Aldrich.Methanol and chloroform were purchased from Panreac and Lab-Scan,respectively.Polyethylene glycol(PEG)of1000g molÀ1molecular weight and methoxy polyethylene glycol(mPEG) of2000g molÀ1molecular weight were obtained from Sigma–Aldrich.Deionized Millipore Milli-Q water was used in all experiments.Alexa Fluor1660Protein Labeling Kit was purchased from Invitrogen.2.2.Synthesis of iron nanoparticlesThe preparation of PEG-stabilized nanoscale zero-valent iron nanoparticles was carried out via a controlled microemulsion method.The microemulsion synthetic methodology makes use of a biphasic heterogeneous solution of water-in-oil in which iron precursors are stirred.Water droplets are used as nucleation sites for the formation of nanoparticles,often in the presence of surfactant molecules dispersed in the oil,essentially forming micelles.The reactions were carried out at room temperature using a single micellar system(sample FePEG-04)and two micellar systems(sample FePEG-02).The procedure followed in thefirstcase is described here.A surfactant solution prepared by dissolving31.5g of polyeth-ylene glycol in105mL of cyclohexane was maintained understirring and degassed for10min under N2atmosphere.Next,6mLof0.33M FeCl2Á4H2O were added to the surfactant solution,stirred and degassed for10min.Metal particles were formed inside thereverse micelles via reduction of the metal salt using an excess ofNaBH4(6mL, 1.76M).After a few minutes,the reaction wasquenched by adding50mL of chloroform and50mL of methanol.The black precipitate was recovered with a permanent magnet,washed several times with methanol and dried under vacuum.The same procedure was carried out in the synthesis performedby two micellar systems with the only difference that the reducingagent(NaBH4),was added in aqueous solution instead of in solidform.This solution,when added toflask reaction,will result thesecond micellar system.Definitely,the method involves mixingtwo microemulsions:one containing the metal salt and the otherthe reducing agent;due to collision and coalescence of the dropletsthe reactants are brought into contact and react to form thenanoparticles.Polyethylene glycol methyl ether(mPEG)shows greaterversatility in functionalization,which increases the potentialapplications of nanoparticles.Specifically,this will be thederivative chosen to functionalize nanoparticles.The syntheseswith this surfactant were carried out at room temperature using asingle-micellar system,0.40g of iron salt,0.20g of the reducingagent,105cm3of cyclohexane and6.0g of water.The concentrationof surfactant in this system was0.095M.2.3.Functionalization of nanoparticles and labelling withfluorescentdyeThe incorporation of thefluorescent molecule to the nano-particles consists of several steps.Firstly,functionalized nano-particles are synthesized and then thefluorophore is anchored.After that the labelled nanoparticles must be purified to take outthe excess dye by size-exclusion chromatography.2.3.1.Modification of mPEGPolyethylene glycol methyl ether(mPEG)of molecular weight2000g molÀ1wasfirstly treated to obtain the aldehyde-derivativeby oxidation of the hydroxyl end groups by dimethylsulfoxide(DMSO)and acetic anhydride at room temperature.Then them-PEG-amine was obtained by the method described by Harriset al.[38],via reduction of the aldehyde groups using sodiumcyanoborohydride in methanol at room temperature.2.3.2.Synthesis of nanoparticles with mPEG-NH2and PEGThe synthesis of nanoparticles was performed by the methodpreviously described for one micellar system.Owing to the smallamount of materialfluorescent necessary,the appropriate amountof mPEG-NH2was used,and the rest was PEG surfactant,as alreadyshown,to provide adequate protection to the nanoparticles.The surfactant consisted of a mixture of7.5g of PEG and217mgof mPEG-NH2,amounts required to have a total surfactantconcentration of0.30M.belling of nanoparticlesThe interaction of metal nanoparticles withfluorophores nearits surface affects the intensity of their emission being critical thedistance between thefluorophore and the surface of thenanoparticle so that thefluorescence is quenched when thedistance is too short.For this study Alexa Fluor660was used.Thisis a succinimidyl ester of Alexa Fluor which exhibits bright fluorescence and high photostability characteristics allowing us to2N.Pérez et al./Journal of Photochemistry and Photobiology A:Chemistry315(2016)1–7capture images that were previously unattainable with conven-tional fluorophores.Moreover it provides an ef ficient and convenient way to selectively link to primary amines.On the other hand,its absorption and fluorescence bands are far from those of the nanoparticles,so that the spectral overlapping is negligible.The PEGylated nanoparticles were fluorescently labelled by reaction with Alexa Fluor 660carboxylic acid succinimidyl ester which formed a chemical bond with the NH 2group of mPEG-NH 2.For that,the procedure established by Invitrogen [39]was followed.Brie fly,a solution of sodium bicarbonate was added to the nanoparticles suspension in order to reach a pH between 7,5and 8,5since succinimidyl esters react ef ficiently at this pH range.The reactive dye was added to the solution and the reaction mixture was stirred for 1h at room temperature.Separation of the labelled nanoparticles from dye which has remained unreacted was carried out using a puri fication column containing the Bio-Rad BioGel P30resin.2.4.Characterization of nanoparticlesThe crystallite phase of the coated nanoparticles was identi fied by recording X-ray diffraction patterns (XRD)using a Bragg –Brentano u /2u Philips diffractometer.Size and shape of nanoparticles were studied by transmission electron microscopy (TEM).Measurements were carried out using a Philips CM 200equipment operating at an accelerating voltage of 200KV.For this,a drop of dilute methanol solution of the nanoparticles was placed onto a copper grid coated with carbon film with a Formvar membrane and allowed to air dry before being inserted into the microscope.Magnetic properties were studied with a vibrating sample magnetometer (VSM).57Fe Mössbauer spectroscopy measurements were carried out at room temperature (RT)in transmission geometry using a conventional spectrometer with a 57Co-Rh source.Reported isomer shift (d )and internal magnetic hyper fine field (BHF)values are relative to metallic Fe at room temperature.The UV –vis absorption spectra were recorded on a Varian double beam spectrophotometer (Cary 4E)in transmittance mode,in the region of 200–900nm.The fluorescence spectra were performed on a SPEX fluorimeter (Fluorolog 3-22).The emission spectra were recorded in the 250–800nm range,by exciting at different wavelengths,depend-ing on the sample.Fluorescence single-particle measurements were performed in a time-resolved fluorescence confocal microscope (model MicroTime 200,PicoQuant).Fluorescence lifetime images (FLIM)are processed with ShymPhotime software (Picoquant)by sorting all photons of one pixel into a histogram and fitted to an exponential decay function to extract lifetime information;the procedure was repeated for every pixel in the image.A 640nm pulsed laser diode,with 70ps pulses was used as excitation source.Spectra were recorded by directing the emission beam to an exit port,where a spectrograph (model Shamrock 300mm)coupled to a CCD camera (Newton EMCCD 1600Â200,Andor)were mounted.3.Results and discussion3.1.Spectroscopic and crystallographic characterizationPolyethylene glycol and polyethylene glycol methyl ether coated iron nanoparticles were characterized by XRD measure-ments as shown in Fig.1.The spectrum of PEG coated samples obtained by one or two micellar systems (Fig.1a)shows three characteristic broad peaks at 2u =44.81 ,65.07 and 82.49 ,which correspond to the (110),(200),and (211)families of planes of the bcc lattice reported for the a -Fe phase.The dimension of the crystallites,D hkl ,was estimated by Scherrer equation in 27.8nm.The nanoparticles obtained with mPEG as surfactant present a diffractogram with a peak of high intensity at 2u =45 ,corre-sponding to the bcc lattice (Fig.1b).This kind of diffractogram is characteristic of samples with low crystallinity and very polydis-perse sizes.From TEM images and histograms (Fig.2),it can be concluded that each Fe/PEG unit consists in a spherical Fe core with an average size of 3.8nm and its own polymeric coating of about 6nm.According to XRD results,the FemPEG-01sample was very polydisperse and it was very dif ficult to obtain a mean diameter.In general,the size of the nanoparticles was between 10and 20nm.The values obtained are similar to those obtained when using nonylphenypentaethoxylated (NP5)[40]as surfactant whose value was around 10nm (Fe core 7.5nm and polymeric shell 2.8nm).PEG provides a thicker coating shell than NP5,probably due to the different molecular weight of both surfactants.3.2.Magnetic propertiesMagnetization vs applied field hysteresis loops were measured using VSM to assess the magnetic properties of the synthesized nanoparticles.The saturation magnetization values were normal-ized to the mass of nanoparticles to yield the speci fic magnetiza-tion,M s (emu g À1).Fig.1.X-ray diffractograms of the synthesized iron nanoparticles:(a)Polyethylenglycol coated samples and (b)polyethylene glycol methyl ether coated sample.N.Pérez et al./Journal of Photochemistry and Photobiology A:Chemistry 315(2016)1–73Fig.3shows the magnetic hysteresis loops of the samples at room temperature.The saturation magnetization of FePEG nano-particles is shown in Table 1.The saturation magnetization arises from both the iron core (218emu g À1),and the iron oxide shell (for Fe 3O 480–92emu g À1),based on the relative weight percentage of iron,iron oxide and non-magnetic coatings on the particle surface.For particles having a similar shell thickness,the weight ratio of the iron core to the iron oxide shell is greater for large particles than for small particles.All the samples have coercitivity less than 15mT and a remanence less than 25A m 2kg À1.This suggested that the particles could aggregate after the removal of the external field due to the remaining magnetization.57Fe Mössbauer spectroscopy measurements were carried out for the FePEG-04sample due to it has the best magneticpropertiesFig.2.Micrographs of (a)FePEG-02,(b)FePEG-04and (c)FemPEG-01samples.Fig.3.Magnetization curves.Table 1Saturation magnetization (Ms),coercitive field (Hc)and remanent magnetization.MuestraMs (A m 2kg À1)Hc (mT)Mr (A m 2kg À1)FePEG-0211615.319.9FePEG-0413513.221.3FemPEG-0110816.819.2Fig.4.RT Mössbauer spectrum for FePEG-04sample.4N.Pérez et al./Journal of Photochemistry and Photobiology A:Chemistry 315(2016)1–7of the studied samples(Fig.4).The RT Mössbauer spectrum qualitatively consist in a sextet(62%of the total area),attributed to bcc Fe(BHF=32.89T and d=À0.106mm sÀ1)coupled to a doublet corresponding to Fe2+or Fe3+.The appearance of both signals would indicate the occurrence of an oxidation process leading to the formation of magnetite(Fe3O4).Any other ordered phase is not observed since more sextets were not found.The iron oxides present in these samples are not magnetically ordered due to the absence of further sextets.This was confirmed by the XPS(Apendix A,Fig.S5)where the peaks at710.30,718.98(small peak)and 723.32eV represent the binding energies of Fe(2p3/2)shake-up satellite2p3/2and2p1/2,respectively.In addition,a small shoulder at705,87eV suggest the peak of2p3/2of zero-valent iron[41].All the studied systems present a high reproducibility as could be confirm in the supporting information(Supporting information (Appendix A))in which the obtained X-ray difratograms and magnetization curves are shown.3.3.Fluorescent measurementsIn this section the photophysical study of the nanoparticlesconjugated with thefluorescent dye is described.Fig.5shows the height-normalized absorption spectrum of the Alexa Fluor1 660and the labelled sample.As can be seen,the absorption spectra are almost identical and show the principal absorption band centred at668nm,indicating the presence of the dye in the nanoparticles.Furthermore,a weak band in the UV region of the spectrum,around250nm,could include iron oxides such as hematite,magnetite or maghemite[42].Fig.6shows the height-normalizedfluorescence spectra of the fraction with the highest content of nanoparticles with dye in suspension at two excitation wavelengths,250and620nm.On the one hand,when the excitation of the sample takes place directly to the absorption band of the dye(620nm,see Fig.5)the emission band is obtained at696nm,emission band typical of Alexa Fluor 6601dye,indicating its presence in the particles.In order to compare thefluorescence efficiency of Alexa660dye in solution and anchored at the nanoparticles,the ratio between the fluorescence intensity and the absorbance of the sample at the excitation wavelength is analysed(Fig.S6).In this way and assuming a quantum yield of around0.37for Alexa660in aqueous solution[36],an estimated quantum yield of around0.13is obtained for the dye at the nanoparticles in suspension On the other hand,when the excitation wavelength wasfixed at250nm (absorption attributed mainly to the iron oxides present in the nanoparticles)the obtained band at390nm can be attributed to the typical emission of nanoparticles of iron oxide present in the sample.In addition,the dye emission band is also present.Although the absorption andfluorescence spectroscopictechniques indicate the presence offluorescence dye in thesuspension of nanoparticles,to confirm the anchorage to thenanoparticles surface confocalfluorescence time resolved micros-copy measurements were carried out.This technique allows thestudy of thefluorescent properties of the dye anchored onto singlenanoparticles[43].In this way it can be obtained informationabout lifetimes of a single particle(Fig.7),and also,through a CCDcamera,a spectrum of thefluorescence in single particle can beobtained(Fig.8).So,by positioning the excitation laser(640nm)in the centre ofeach nanoparticle,thefluorescence spectrum of the anchored dyenanoparticle is obtained(Fig.8).In addition,thefigure includes thespectrum of dye in solution measured at the same conditions.Themaximum offluorescence are696nm for dye and687nm for thedye anchored to nanoparticles.The displacement of the maximumtowards lower wavelength,is a typical effect of dyes adsorbed insurfaces,as the case of the iron nanoparticles.Fig.9shows thefluorescence decay curves obtained by confocalmicroscopy for the dye in solution and labelled dye in eachnanoparticle and respective histograms.The half lifetime of free dye presents monoexponencialbehaviour,with a value offluorescence life time t=1.8ns,while the conjugated nanoparticles presents a biexponencial behaviourwith:life time t1%0.1–0.5ns y t2=1.5–1.7ns(Fig.9).These values have been obtained after the analysis of,at least,10individualparticles.The short half lifetime,around0.1–0.6ns can be attributed tothe light scattered by the nanoparticle itself and the obtained longhalf life time(t2=1.5–1.7)is attributed to anchored dye to nanoparticle surface.AbsorbanceWavelength (nm)Fig.5.Height-notmalized absorption spectra of Alexa Fluor660dye and ironlabeled nanoparticles in aqueous buffer suspension.FluorescenceIntensity(a.u.)Wavelength (nm)Fig.6.Height-normalizedfluorescence spectra of iron nanoparticles in aqueousbuffer suspension at excitation wavelengths of250and620nm.Fig.7.Fluorescence microscopy image of single particles.N.Pérez et al./Journal of Photochemistry and Photobiology A:Chemistry315(2016)1–75The slight decrease of the long lifetime of anchored dye regarding the diluted suspension of the nanoparticle can be attributed to the dye quenching due to the presence of iron oxide.Confocal fluorescence microscopy con firmed that the dye is labelled onto nanoparticles and maintains its fluorescent proper-ties.Therefore,the trajectory of these nanoparticles may be monitored by fluorescence microscopy under red excitation in vitro or in vivo experiments.4.ConclusionsIn this study,iron nanoparticles coated with PEG and mPEG were prepared and characterized.The nanoparticles present high magnetic susceptibility and sizes between 10and 15nm.It is noteworthy that the synthesized nanoparticles are mainly zero-valent iron.The FemPEG nanoparticles were successfully functionalized and conjugated with a fluorescent dye.Thus,amine-reactive N -hydroxysuccinimidyl ester of Alexa Fluor 660dye was conju-gated to the nanoparticle surface.This dye produces bright far red fluorescence emission with a peak at 690nm under red excitation light (in the clinic window).Studies of confocal fluorescence microscopy con firmed that the fluorescent dye is attached to the nanoparticles and retains itsfluorescent properties which could make possible to monitor the course of in vitro or in vivo samples using fluorescent microscopy red under excitation.The magnetic properties of synthesized nanoparticles added to its fluorescent response result in a suitable material for be detected by both magnetic and fluorescent techniques for combined MR/Optical imaging applications.AcknowledgementsAuthors thank the Basque Country Government for financial support (ACTIMAT project,ETORTEK programme IE10-272)(Ayu-das para apoyar las actividades de los grupos de investigación del sistema universitario vasco,IT718-13and IT339-10).Technical and human support provided by SGIKER (UPV/EHU,MICINN,GV/EJ,ERDF and ESF)is gratefully acknowledged.V.M.M.acknowledges the Ramon y Cajal contract with the Ministerio de Economía y Competitividad,(RYC-2011-09505).Appendix A.Supplementary dataSupplementary data associated with this article can be found,in the online version,at /10.1016/j.jphotochem.2015.09.004.References[1]I.L.Medintz,H.T.Uyeda,E.R.Goldman,H.Mattoussi,Quantum dotbioconjugates for imaging,labelling and sensing,Nat.Mater.4(2005)435–446./10.1038/nmat1390.[2]X.Michalet,F.F.Pinaud,L.A.Bentolila,J.M.Tsay,S.Doose,J.J.Li,et al.,Quantumdots for live cells,in vivo imaging,and diagnostics,Science 307(80)(2005)538–544,doi:/10.1126/science.1104274.[3]K.L.Kelly,E.Coronado,L.L.Zhao,G.C.Schatz,The optical propierties of metalnanoparticles:the in fluence of size,shape,and dielectric environment,J.Phys.Chem.B 107(2003)668–677,doi:/10.1021/jp026731y .[4]K.Woo,J.Hong,S.Choi,H.-W.Lee,J.Ahn,C.S.Kim,et al.,Easy synthesis andmagnetic properties of iron oxide nanoparticles,Chem.Mater.16(2004)2814–2818,doi:/10.1021/cm049552x .[5]W.S.Seo,H.H.Jo,K.Lee,B.Kim,S.J.Oh,J.T.Park,Size-dependent magneticproperties of colloidal Mn3O4and MnO nanoparticles,Angew.Chem.Int.Ed.43(2004)1115–1117,doi:/10.1002/anie.200352400.[6]M.Colombo,S.Carregal-Romero,M.F.Casula,L.Gutierrez,M.P.Morales,I.B.Bohm,et al.,Biological applications of magnetic nanoparticles,Chem.Soc.Rev.41(2012)4306–4334,doi:/10.1039/c2cs15337h .[7]S.Cheong,P.Ferguson,K.W.Feindel,I.F.Hermans,P.T.Callaghan,C.Meyer,et al.,Simple Synthesis and functionalization of iron nanoparticles formagnetic resonance imaging,Angew.Chem.Int.Ed.50(2011)4206–4209,doi:/10.1002/anie.201100562.[8]Q.Pankhurst,N.Thanh,S.Jones,J.Dobson,Progress in applications of magneticnanoparticles in biomedicine,J.Phys.D.Appl.Phys.42(2009),doi:/10.1088/0022-3727/42/22/224001.[9]A.B.Salunkhe,V.M.Khot,S.H.Pawar,Magnetic hyperthermia with magneticnanoparticles:a status review,Curr.Top.Med.Chem.14(2014)572–594,doi:/10.2174/1568026614666140118203550.[10]S.Peng,C.Wang,J.Xie,S.Sun,Synthesis and stabilization of monodisperse Fenanoparticles,J.Am.Chem.Soc.128(2006)10676–10677,doi:/10.1021/ja063969h .[11]Z.Wang,X.Li,M.Gao,X.Zeng,One-step preparation of amorphous ironnanoparticles by laser ablation,Powder Technol.215–216(2012)147–150,doi:/10.1016/j.powtec.2011.09.039.[12]D.Farrell,S.Majetich,J.Wilcoxon,Preparation and characterization ofmonodisperse Fe nanoparticles,J.Phys.Chem.B.107(2003)11022–11030,doi:/10.1021/jp0351831.[13]C.S.Tiwary,S.Kashyap,K.Biswas,K.Chattopadhyay,Synthesis of pure ironmagnetic nanoparticles in large quantity,J.Phys.D.Appl.Phys.46(2013)385001,doi:/10.1088/0022-3727/46/38/385001.[14]O.Veiseh,J.Gunn,M.Zhang,Design and fabrication of magnetic nanoparticlesfor targeted drug delivery and imaging,Adv.Drug Deliv.Rev.62(2011)284–304,doi:/10.1016/j.addr.2009.11.002Design .[15]J.E.Macdonald,J.a Kelly,J.G.C.Veinot,Iron/iron oxide nanoparticlesequestration of catalytic metal impurities from aqueous media and organic reaction products,Langmuir 23(2007)9543–9545,doi:/10.1021/la7011827.[16]I.San Román,M.L.Alonso,L.Bartolomé,E.G.Galdames,M.O.oiti,et al.,Relevance study of bare and coated zero valent iron nanoparticles for lindane degradation from its by-product monitorization,Chemosphere 93(2013)1324–1332,doi:/10.1016/j.chemosphere.2013.07.050.Fig.8.Fluorescence spectrum of a single particle (red curve)and a diluted dye solution (black curve)registered in time-resolved fluorescence confocal microscope at excitation wavelength of 640nm.(For interpretation of the references to colour in this figure legend,the reader is referred to the web version of thisarticle.)Fig.9.Fluorescence decay curves of Alexa Fluor 660and two different regions.6N.Pérez et al./Journal of Photochemistry and Photobiology A:Chemistry 315(2016)1–7。

井冈山大学学报(自然科学版)21文章编号：1674-8085(2018)04-0021-07SYNTHESIS, CRYSTAL STRUCTURE AND PROPERTIESOF A TRINUCLEAR COPPER(II) COMPLEXCu 3(TBSSB)2(BSA) 2(bipy)2·H 2O*ZHONG Fan ，CAI Jin-hua(School of Chemistry and Chemical Engineering, Institute of Applied Chemistry, Jinggangshan University, Ji ’an, Jiangxi 343009, China)Abstract ：A trinuclear copper(II) complex Cu 3(TBSSB)2(BSA)2(bipy)2·H 2O (1) with mixed ligands of taurine-5-bromo-salicylaldehyde Schiff base (TBSSB), 5-bromo-salicylaldehyde (BSA) and 2,2’-bipyridine(bipy), was synthesized and characterized by elemental analysis, infrared spectrum, single crystal X -ray, photoluminescent, solid-state diffuse reflectance spectrum and molecular orbital analysis. The results of X -ray crystallographic analysis indicate that the complex belongs to triclinic and space group P ī with a = 10.031(2) Å, b = 11.480(2) Å, c = 12.913(3) Å, α = 73.13(3)°, β = 78.58(3)°, γ = 75.24(3)°, V = 1363.6(5) Å3, Z = 1, M r = 1533.30, Dc = 1.867 g/cm 3, F (000) = 759, μ = 4.236 mm -1, S = 0.921, R 1 = 0.0488, wR 2 = 0.0471(I > 2σ(I )), R 1 = 0.1812 and wR 2 = 0.0546. Cu(2) atom adopts a square geometry coordinated by two N and two O atoms from two separated TBSSB ligands, while the other two equal Cu(1) atoms exhibit a square-pyramidal environment formed by two N atoms of bipy, one O of TBSSB and two O of BSA. The intramolecular interactions (O −H ···Br) and intermolecular interactions (C −H ···O) link the molecules into a complicated three-dimensional (3D) supramolecular structure. Photoluminescent investigation reveals that it displays an emission in the blue region. Optical absorption spectra reveals the presence of an energy band gap of 2.19 eV . Key words: copper complex; crystal structure; taurine; photoluminescence; supermoleculeCLC number:O641 Document code:A DOI:10.3969/j.issn.1674-8085.2018.04.005三核铜配合物[Cu 3(TBSSB)2(BSA)2(bipy)2]·H 2O 的合成、晶体结构及性质研究*钟 凡， 蔡金华(井冈山大学化学化工学院，应用化学研究所，江西，吉安 343009)摘 要：以牛磺酸缩5-溴水杨醛席夫碱（TBSSB ）、5-溴水杨醛（BSA ）、2,2’-联吡啶(bipy)为混合配体，合成了三核铜配合物[Cu 3(TBSSB)2(BSA)2(bipy)2]·H 2O(1)，并对该化合物进行了元素分析、红外光谱、X -射线单晶衍射、光致发光光谱、固体漫反射光谱及分子轨道分析等表征。