Designing Functional Aromatic Multisulfonyl Chloride Initiators for Complex Organic Synthesis by Living Radical Polymerization
VIRGIL PERCEC,1BOGDAN BARBOIU,1TUSHAR K.BERA,1MARCEL VAN DER SLUIS,1ROBERT B.GRUBBS,2 JEAN M.J.FRE′CHET2
1Roy&Diana Vagelos Laboratories,Department of Chemistry,University of Pennsylvania,
Philadelphia,Pennsylvania19104-6323
2Department of Chemistry,University of California,Berkeley,California94720-1460
Received8September2000;accepted14September2000
ABSTRACT: The similarities and differences between sulfonyl chloride and alkyl halide
initiators for metal-catalyzed living radical polymerizations are discussed.The differ-
ences in the rates of formation,reactivities,and reactions of primary radicals derived
from sulfonyl halides and alkyl halides demonstrated the design principles for mono-
sulfonyl and multisulfonyl chlorides that provided quantitative initiation and higher
rates of initiation than of propagation.Multifunctional initiators with two,three,four,
six,and eight sulfonyl chloride groups that produced perfect star polymers in95%
conversions were designed and synthesized on the basis of these principles.?2000John
Wiley&Sons,Inc.J Polym Sci A:Polym Chem38:4776–4791,2000
Keywords:living radical polymerization;multisulfonyl chloride initiators;reactivity;
star polymers
INTRODUCTION
Scientists in the continuously growing?eld of polymer synthesis recognized long ago that living polymerizations1provide the most versatile method for the synthesis of well-de?ned polymers with controlled molecular weights and functional chain ends.The physical properties of polymers obtained by various living polymerization mech-anisms(i.e.,anionic,cationic,metathesis,coordi-native,and radical)are different from those of the same polymers prepared by less controlled pro-cesses,such as the homologous chain polymeriza-tion reactions.Moreover,access to polymers with complex architectures through living polymeriza-tions is opening a level of structural control that is competitive only with that generated via or-ganic synthesis.From the synthesis of simple diblock copolymers to complex structures such as macrocyclic,2star,3and hyperbranched poly-mers,4the only limit is imagination.The design of reaction conditions and the optimization of yields for all the individual reaction steps involved in a living polymerization(i.e.,initiation,propaga-tion,and termination)are key parameters in-volved in the synthesis of any complex polymer architecture.
Metal-catalyzed living radical polymerizations (LRPs)are complementary to the stable free-rad-ical polymerization mediated by nitroxide radi-cals.5Both polymerization processes require a suitable adjustment between the structure of the monomer,initiator,and atom or group of atoms that provide the reversible termination to gener-
Correspondence to:V.Percec(E-mail:jpschem@sas.upenn. edu)
Journal of Polymer Science:Part A:Polymer Chemistry,Vol.38,4776–4791(2000)?2000John Wiley&Sons,Inc.
4776
ate a higher rate of initiation than propagation and a high initiator ef?ciency.Therefore,each process is restricted to the polymerization of se-lected classes of activated ole?ns.The comple-mentarity of these two polymerization techniques has been used in the synthesis of hyperbranched polymers.4
Publications on metal-mediated radical poly-merizations initiated with alkyl halides,with un-elucidated extents of control of each individual step,contributed to the present state of knowl-edge in the ?eld of radical polymerization.6The groups of Sawamoto 7and Matyjaszewski,8in-spired by the landmark work of Otsu et al.,6(g)reported in 1995the LRP of vinyl monomers ini-tiated with alkyl halides.In the same year,we demonstrated that arylsulfonyl halides 9–15and subsequently alkylsulfonyl 13–15(a)and per?u-oroalkylsulfonyl 16halides represent a universal class of functional initiators 14for heteroge-neous 9–15,17and homogeneous 10,14(a)metal-cata-lyzed LRPs of styrene (S),methacrylates,and ac-rylates.
The catalytic systems used so far both with sulfonyl halide and alkyl halide initiators are based on various transition-metal salts (Scheme 1).The preferred ones in many laboratories are based on CuX and an organic ligand such as un-substituted or 4,4?-disubstituted 2,2?-bipyridine (bpy).We demonstrated that Cu 2O,in conjunc-tion with bpy,self-regulates in a phase-transfer-catalyst (PTC)process mediated by thermally sta-ble multidentate acyclic neutral ligands,the LRP of S and methacrylates initiated with alkyl or arylsulfonyl chlorides.15This is the catalyst of choice for the synthesis of complex polymer archi-tectures by LRP because it provides mild reaction conditions and a neutral or slightly basic reaction medium,useful for in situ acid-sensitive reac-tions.In contrast to Cu 2O LRP,CuCl LRP pro-duces an acidic reaction medium.Less acidic and more soluble catalysts based on Cu I X displaying increased rates of propagation were reported re-
cently by our laboratory,17and their use for the synthesis of polymers with complex architecture is under investigation.
The monoaddition of sulfonyl and alkyl radi-cals to ole?ns and acetylenes followed by the transfer of a halide atom to the resulting radical is known as Kharasch addition or atom transfer radical addition (ATRA).18Unlike with carbon radicals,the addition of arylsulfonyl radicals to ole?ns is reversible,19(c)and this changes the overall kinetics of the initiation reaction.This equilibrium is determined by the nature of the substituent attached to the ole?n and its ability to stabilize the resulting radical by resonance.20
The mechanism presented in Scheme 2details the main steps involved in the metal-catalyzed LRP initiated with sulfonyl halides.10Initiation can be spontaneous or can be promoted by UV,21various sources of radicals,22or thermolysis,22and it is catalyzed by metals 23,34that reduce the corresponding sulfonyl halide to a sulfonyl radi-cal.Substituted and unsubstituted aryl and alkyl sulfonyl halides undergo bond homolysis,and the resulting electrophilic sulfonyl radicals subse-quently add to substituted and unsubstituted ole-?ns 22–24(a–c)and acetylenes,21without 21–24(a–c)and with 24(d)the extrusion of SO 2to yield the corresponding alkyl and vinyl halides.During propagation,depending on the nature of the sub-stituent(s)present on the ole?n,the resulting al-kyl halides can undergo,under identical reaction conditions,addition to the same ole?n.25More than one monomer addition followed by atom transfer is regarded as a side reaction (i.e.,oli-gomerization)of ATRA.18The higher rate of prop-agation and broader molecular weight distribu-tion in LRP are due to the increased number of monomer additions before each atom transfer step takes place.
The propagation and reversible termination steps of LRP initiated with sulfonyl halides and alkyl halides are identical.26,27However,the ini-tiation step of these two polymerizations
differs
Scheme 1.Selected catalysts used for LRP.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4777
substantially.The metal-catalyzed reduction of the substituted arylsulfonyl halides to the corre-sponding sulfonyl radicals is faster than that of the resulting alkyl halides,so arylsulfonyl halides facilitate a higher rate of initiation than propaga-tion.A faster rate of initiation versus propagation is the primary requirement for the synthesis of polymers with narrow molecular weight distribu-tions via LRP.A quantitative initiation is also the ?rst step toward the elaboration of synthetic pro-cedures required in the synthesis of complex or-ganic molecules via LRP.
For sulfonyl halides,the sulfonyl radicals formed are more stable than the carbon-cen-tered radicals obtained when alkyl halides are used as initiators.14The mechanism depicted in Scheme 3shows the possible reaction products obtained from the sulfonyl radical dimeriza-tion.28Only disproportionation reaction prod-ucts,as described by Scheme 3(eq 4),were observed 28in the absence of monomer.Al-though the sulfonyloxy radical can also initiate the polymerization,the sul?nyl radical does not act as an initiator.28(d)Their adduct sul?nylsul-fonate (eq 3)also cleaves to regenerate sulfonyl radicals.The overall effect of these reactions is that,although the sulfonyl radicals do combine,their combination is reversible,so they become stable through this fast equilibrium.The mech-anism of stabilization involves sul?nyl radicals that do not initiate or dimerize easily (eq 6).Therefore,we believe that they are persistent and accumulate.The concentration of sulfonyl-oxy radicals with which it is in equilibrium decreases,and the parent sulfonyl radical be-comes persistent also.
For aromatic sulfonyl halides,the rate of the quantitative initiation is much faster than the rate of propagation,14regardless of the func-tional groups attached to the aromatic part of the sulfonyl halide initiator.13For sulfonyl chlo-ride initiators,we directly measured both the rate constant of initiation {Scheme 4;k i app was derived 14from the slope of ln([I]0/[I])vs time}and the rate constant of propagation (k p app )and compared them at the polymerization tempera-ture.For S and methyl methacrylate (MMA),k i app is four orders of magnitude higher than k p app (k i app /k p app ?5.2?104and 1.7?104,respectively).This difference decreases to al-most three orders of magnitude (k i app /k p app ?4.4?103)for butyl acrylate and two orders of magnitude (k i app /k p app ?6.5?102)for methyl acrylate.14
In contrast,the structure of an alkyl halide initiator should be tailored for each class of mono-mers to obtain a rate of initiation at least equal to that of propagation.No experimental values of both initiation and propagation rate constants are available for alkyl halide initiators,so it is widely accepted that the two should have similar values.When alkyl halides are used as initiators,the initiation step is governed by the persistent rad-ical effect.29The alkyl radicals formed during
the
Scheme 2.Mechanism of the metal-catalyzed LRP initiated with arylsulfonyl chlo-rides.
4778PERCEC ET AL.
Scheme 3.Mechanism of the sulfonyl radical
dimerization.
Scheme 4.Determination of k i exp in the LRP of MMA by 1H NMR spectroscopy.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4779
initiation step are very reactive and combine ir-reversibly to form stable dimers.3(g)This com-bination reaction decreases the initiator ef?-ciency and creates excess Cu II in the polymer-ization mixture.3(g),27(b)The formed Cu II species decreases the dimerization rate,and the reac-tion attains a pseudoequilibrium Cu I/Cu II and a pseudosteady concentration of radicals for the rest of the propagation process.A too fast initi-ation with an alkyl radical will favor combina-tion reactions,for example,low initiator ef?-ciency,before the amount of Cu II generated lim-its this side reaction.This process is present only in the early stages of propagation for the sulfonyl chloride initiators because during initia-tion reversible combination products(Scheme3, eq3)are formed.For sulfonyl halides,the extent of combination is much decreased versus alkyl halides because during the?rst propagation steps there is already excess Cu II present from the ini-tiation step.A slow initiation would overlap with the propagation,and the overall effect would be a broad molecular weight distribution because not all chains would be started at the same time. Therefore,it is only in the case of sulfonyl halide initiators that the large difference between the rates of initiation and propagation obtained is of interest for the construction of polymers with well-de?ned and complex architectures.More-over,because the sulfonyl radical(a?radical)is not conjugated with the aryl group,the electronic effects derived from different substituents at-tached to the phenyl ring affect the reactivity of the sulfonyl chloride group to a very limited
extent.19Only a weak inductive effect from the substituents attached to the phenyl group was observed for model reactions for the arylsulfo-nyl chloride addition to vinyl monomers,as demonstrated by Hammett plots.19(b)This fea-ture of the sulfonyl radicals translates into an extremely versatile methodology for chain-end functionalization of the polymers synthesized by substituted arylsulfonyl chloride-initiated LRP.13
In this article,we report a detailed investiga-tion of the electronic and structural effects gener-ated by the introduction of functional and/or mul-tiple sulfonyl chloride groups on the initiation ef?ciency,side reactions,and rate of propagation observed in metal-catalyzed LRP systems initi-ated with functional aromatic monosulfonyl and multisulfonyl chlorides.RESULTS AND DISCUSSION
Functional Monosulfonyl Chloride Initiators Substituted arylsulfonyl chloride initiators(Scheme 5)were used in the LRP of S and MMA and showed similar rates of propagation and M w/M n (weight-average molecular weight/number-aver-age molecular weight).Several synthetically use-ful groups with both electron-withdrawing and electron-donating character,O COOH,O PhOH, O NH2,O N(CH3)2,O COCH3,and O N A N O, were successfully introduced onto the polymer chain end.13The two catalysts used,Cu2O and CuCl,in the presence of bpy showed a?rst order of reaction in monomer concentration{the linear-ity of ln([M]0/[M])vs time}.In comparison,the Cu2O catalyst[Fig.1(a)]had an induction period because of its insolubility in the reaction
mix-Scheme5.Examples of functional alkyl and arylsul-fonyl chloride initiators.
4780PERCEC ET AL.
ture 15and also gave a longer reaction time.How-ever,the ?nal molecular weight distribution was much narrower:M w /M n ? 1.12versus 1.20.As proven by the points ?tting the diagonal (ef?-ciency ?100%)in the M n versus the theoretical molecular weight,M th (M th ?FW mon ?[M]0/[I]0)plots in Figure 1(a–c),all initiators gave quanti-tative initiation regardless of the position of the substituent,that is,ortho or para to the sulfonyl chloride,and its electronic nature,that is,elec-
tron-withdrawing or electron-donating.This also demonstrates that steric hindrance makes no con-tribution or only a minor contribution to the re-activity of sulfonyl radicals.Functional Disulfonyl and Trisulfonyl Chloride Initiators
The introduction of a second sulfonyl group in the initiator molecule was studied in detail to provide
a
Figure 1.Metal-catalyzed LRP of MMA initiated with functional monosulfonyl chlo-rides and catalyzed by (a)MBSC/Cu 2O,(b)CASC/CuCl,and (c)DHSC/CuCl at 90°C.Reaction conditions:(a)[MMA]?4.7M,PhOPh,[MMA]/[MBSC]/[Cu 2O]/[bpy]?100/1/2/4molar ratio,and (b,c)[MMA]?6.2M,p -xylene,[MMA]/[I]/[CuCl]/[bpy]?200/1/1/3molar ratio.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4781
rational approach to the design of functional multi-sulfonyl chloride initiators capable of quantitative and fast initiation from more than one sulfonyl group.Preliminary data from our group demon-strated that linear polymers with identical chain
ends could by synthesized by LRP with a diphenyl
ether-derived disulfonyl chloride di-initiator(PDSC;
Scheme6).12New disulfonyl chloride initiators
were used as initiators for the LRP of MMA and
S.The two sulfonyl chloride groups in para-
benzenedisulfonyl chloride(Scheme6;pBDSC)
had different reactivities.Therefore,the polymers
that resulted did not have narrow molecular
weight distributions and controlled molecular
weights.The sulfonyl chloride group was an ex-
tremely strong electron-withdrawing substituent
(vs the SO2CH2O that resulted after addition to the monomer),and it affected the reactivity of the
second sulfonyl chloride group.At?rst sight,this
is an unexpected result because the sulfonyl rad-
icals were not conjugated with the aryl group.We
synthesized the monoadduct of pBDSC30to MMA
(pBDSC-MMA)and used it as an initiator.This
initiator generated poly(methyl methacrylate)
(PMMA)with a controlled molecular weight and a
narrow molecular weight distribution[Fig.
2(a)].
Figure2.LRP of MMA catalyzed by Cu
2
O/bpy in p-xylene and initiated with(a) mBDSC(?;[MMA]/[mBDSC]?200/1)and pBDSC-MMA(F;[MMA]/[pBDSC-MMA]
?100/1)and(b)ABDSC.Reaction conditions:(a,b)[MMA]?6.2M,90°C;(a)[MMA]/
[Cu
2
O]/[bpy]?100/1/2molar ratio;and(b)[MMA]/[ABDSC]/[Cu
2
O]/[bpy]?100/1/2/4 (?)or100/0.5/1/2(F)molar
ratios.
Scheme6.Aryl disulfonyl chloride initiators.
4782PERCEC ET AL.
For the meta -benzenedisulfonyl chlorides from Scheme 6(mBDSC and ABDSC 30),the second sulfonyl chloride was so deactivated that a signif-icant amount of side reactions occurred during polymerization,as evidenced by the curvature of M n versus M th .As shown in Table I,entries 2,4,and 6,the LRPs of PDSC,mBDSC,and ABDSC had,within experimental error,the same rate constant of propagation,k p exp ,as the concentra-tions of O SO 2Cl and the catalyst were identical.Attempts to synthesize,by standard literature procedures,19(a)the adduct of mBDSC to MMA produced a mixture of adduct and polymeric ma-terials.This demonstrated that a large extent of side reactions occurred for this compound during activation by metal salts.
To con?rm these unexpected results,a less con-jugated,space-separated,disulfonyl chloride-functional (acetophenone)initiator (Scheme 6;ATPDSC)was synthesized 30and compared to PDSC as an initiator in the LRP process (Fig.3).We observe in Figure 3(b)versus Figure 3(a)that the induction period present when Cu 2O/bpy is used as a catalyst can be removed by the use of simple PTCs,such as ethylene glycol (EG).How-ever,an increase in M w /M n from 1.07to 1.18is also observed.In Figure 3(c),a narrow molecular weight distribution (M w /M n ?1.07)and 100%initiator ef?ciency proved that reducing the con-jugation in the ATPDSC initiator (the biphenyl group is only partially conjugated because it is twisted)and space-separating the sulfonyl chlo-ride initiating groups opens the route to ef?cient multifunctional initiators for LRP.In addition,the acetophenone group from ATPDSC is useful for further chemical transformations.
The aniline-derived trichlorosulfonyl initiator (ATSC;30Fig.4)provided the ?rst surprise.As shown in Figure 4(a),in the presence of two Cu-based catalysts,this initiator gave well-controlled polymerizations with predetermined molecular weights and narrow molecular weight distributions (M w /M n as low as 1.12).Kinetically,as shown in Table I,entries 3versus 11,under the same condi-tions this initiator had a similar rate constant of propagation with the PDSC initiator (k p exp ?1.2vs 1.3h ?1).The underestimation of the M n by gel permeation chromatography (GPC)versus M th was due to the presence of the three arms in the poly-mer.The cleavage of a polystyrene (PS)obtained by
Table I.Metal-Catalyzed Living Radical Polymerization of Methacrylates a Initiated with Multisulfonyl Chloride Initiators
No.Monomer Initiator Arms Catalyst/Ligand k p exp (h ?1)
M w /M n Conversion
(%)Time (h)[M]/[O SO 2Cl]
1MMA MBSC 1Cu 2O/bpy 0.33e 1.1397111002MMA PDSC b 2Cu 2O/bpy 0.19e 1.1298211003BMA PDSC 2Cu 2O/bpy 1.34e 1.0797 5.61004MMA mBDSC b 2Cu 2O/bpy 0.15 1.0992171005MMA ABDSC c 2Cu 2O/bpy 0.47 1.2590 4.7506MMA ABDSC b
2Cu 2O/bpy 0.17 1.1784111007MMA pBDSC-MMA c 2Cu 2O/bpy 0.17 1.139517508MMA ATPDSC 2Cu 2O/bpy 0.18e 1.0799281009MMA 3PSC
3Cu 2O/bpy 0.18e 1.06982210010MMA 3PMMA133Cu 2O/bpy 0.19 1.0798*******BMA ATSC 3Cu 2O/bpy 1.20e 1.1198 5.510012BMA ATSC 3Cu(0)/bpy 2.90e 1.2798 1.610013BMA STAR4d 4CuCl/bpy 0.37 1.269810.520014MMA STAR44Cu 2O/bpy 0.54 1.1688 4.010015MMA STAR4d 4Cu 2O/bpy 0.29 1.20908.020016MMA C44Cu 2O/bpy 0.37 1.13958.010017MMA C66Cu 2O/bpy 0.59 1.1692 4.310018
MMA C8f
8
Cu 2O/bpy
0.12
1.07
93
22
100
a Conditions:[MMA]?4.7M at 90°C;[BMA]?4.5M at 120°C;[M]/[O SO 2Cl]/[catalyst]/[bpy]?100/1/1/2molar ratio;PhOPh.b
Conditions:the same as those listed in footnote a,except [MMA]?6.2M.c
Conditions:the same as those listed in footnote b,except [M]/[O SO 2Cl]/[catalyst]/[bpy]?50/1/1/2molar ratio.d
Conditions:the same as those listed in footnote a,except [M]/[O SO 2Cl]/[catalyst]/[bpy]?200/1/1/2molar ratio.e
Induction period due to the absence of binding of the Cu 2O by the initiator.f
Conditions:the same as those listed in footnote a,except [M]/[O SO 2Cl]/[catalyst]/[bpy]?100/1/0.5/1molar ratio.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4783
LRP with this initiator under basic reaction condi-tions (Scheme 7)con?rmed the presence of three arms (S usually gives broader molecular weight dis-tributions under these LRP conditions,but PMMA is not stable under strong basic conditions).On the basis of kinetic results,we concluded that this ini-tiator had three sulfonyl groups interacting.How-ever,all of them initiated the polymerization with the same rate.This result could be explained by the fact that an O NH 2group with a strong electron-donating effect was compensating for the electron-withdrawing effect of the sulfonyl chloride groups.Another trisulfonyl chloride initiator (3PSC)with a nonconjugated structure was synthe-sized 30and used successfully for the LRP of MMA [Fig.4(b)].It is noteworthy for 3PSC and its ad-duct to MMA (3PMMA13)that the rate constant of propagation (k p exp ),M n ,and molecular weight distribution dependencies were identical between them and ?t the data for the ATPDSC initiator under identical reaction conditions (Table I,en-tries 8–10).The removal of the induction period usually associated with the use of Cu 2O/bpy as a catalyst was due to the binding effect created
by
Figure 3.LRP of methacrylates catalyzed by Cu 2O/bpy in p -xylene initiated with (a,b)PDSC and (c)ATPDSC.Reaction conditions:(a–c)[BMA]?4.5M,[MMA]?4.7M;(a)[BMA]/[PDSC]/[Cu 2O]/[bpy]?200/1/2/6molar ratio,120°C;(b)[BMA]/[PDSC]/[Cu 2O]/[bpy]?200/1/2/6molar ratio,[PDSC]/[EG]?1/15mol/mol,120°C;and (c)[MMA]/[ATPDSC]/[Cu 2O]/[bpy]?200/1/4/8molar ratio,90°C.
4784PERCEC ET AL.
the large adduct molecule 3PMMA13.This effect was similar to other reported PTCs 17[i.e.,EG in Fig.3(b)],although no broadening of the molecu-lar weight distribution was observed.
In conclusion,to design initiators with multi-ple sulfonyl chloride groups,we need to consider the following strategic options:
1.Decrease the conjugation between the sulfo-nyl chloride groups.
2.Eliminate the conjugation between the sul-fonyl chloride groups.
https://www.doczj.com/doc/cd8068231.html,pensate the strong electron-withdraw-ing effect of the sulfonyl chloride group by strong electron-donating groups (i.e.,O NH 2,O OCH 3).Tetrasulfonyl,Hexasulfonyl,and Octasulfonyl Chloride Initiators
A tetrasulfonyl chloride initiator with a nonconju-gated structure (STAR4;Scheme 8)was synthe-sized 30and used for the CuCl/bpy-catalyzed LRP of n -butyl methacrylate (BMA)[Fig.5(a)]and
the
Figure 4.LRP of methacrylates (a)initiated with ATSC and catalyzed by Cu/bpy (?)or Cu 2O/bpy (F )and (b)initiated with 3PSC (F )or its adduct to MMA,3PMMA13(?),and catalyzed by Cu 2O/bpy.Reaction conditions:(a)[BMA]?4.5M,PhOPh,[BMA]/[ATSC]/[catalyst]/[bpy]?300/1/3/6molar ratio,120°C and (b)[MMA]? 4.7M,p -xylene,[MMA]/[I]/[Cu 2O]/[bpy]?300/1/6/12molar ratio,90°C.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4785
Cu 2O/bpy-catalyzed LRP of MMA and S [Fig.5(b,c)].This initiator had the same PTC effect noted previously for EG and 3PMMA13;that is,it re-moved the induction period associated with the use of Cu 2O/bpy as a catalyst.Polymers with well-con-trolled molecular weights and M w /M n as low as 1.18were obtained.The cleavage of the STAR4initiator core for a PMMA (Scheme 9)and a PS (Scheme 10)demonstrated the tetrafunctionality of the initiator and,therefore,the equal reactivity of all initiating groups.In both cases,M n per cleaved arm was about one-quarter of the M n of the star polymer,and the molecular weight distribution of the cleaved arms was within the range of values obtained with monofunctional initiators.
Initiators with four,six,and eight noninter-acting sulfonyl chloride groups attached on calixarene cores (Scheme 8)were synthesized 30and tested for the LRP of MMA.Kinetic results presented in Figure 6prove their PTC effect on Cu 2O/bpy (previously discussed)and also an excellent capability to avoid chain-breaking re-actions (i.e.,termination by combination)up to conversions as high as 95%.This result was extremely rewarding because it has been reported 3(e,g,h)that the synthesis of star poly-mers by LRP with alkyl halide initiators had a limiting conversion of 38%if no radical termi-nation by combination reactions were to be ob-served.Our result proves unequivocally that because of the absence of side reactions,aryl-sulfonyl chlorides are indeed the initiators of choice for the synthesis of polymers with com-plex architectures by LRP.Figure 7shows size exclusion chromatography (SEC)traces from a kinetic experiment using C8[Fig.6(c)]and demonstrates that with this octasulfonyl chlo-ride initiator,conversions up to 93%with no signi?cant termination by combination can be
obtained.
Scheme 8.Trisulfonyl,tetrasulfonyl,hexasulfonyl,and octasulfonyl chloride initia-tors with equal reactivity of the sulfonyl chloride
groups.
Scheme 7.Synthesis of a three-arm star PS by LRP initiated from ATSC and the cleavage of its three PS arms.
4786PERCEC ET AL.
Figure 5.Metal-catalyzed LRPs initiated with STAR4for (a)BMA,with CuCl/bpy as a catalyst;(b)MMA,with Cu 2O/bpy as a catalyst;and (c)S,with Cu 2O/bpy as a catalyst.Reaction conditions:(a)[BMA]?4.5M,p -xylene,[BMA]/[STAR4]/[CuCl]/[bpy]?800/1/8/16molar ratio,120°C;(b)[MMA]?4.7M,PhOPh,[MMA]/[Cu 2O]/[bpy]?100/1/2molar ratio,90°C,(l)[MMA]/[STAR4]?100/1mol/mol,and (s)[MMA]/[STAR4]?200/1mol/mol;and (c)[S]? 4.4M,PhOPh,[S]/[STAR4]/[Cu 2O]/[bpy]?800/1/4/8molar ratio,120
°C.
Scheme 9.Synthesis of a four-arm star PMMA by LRP initiated from STAR4and the cleavage of its four PMMA arms.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4787
EXPERIMENTAL
Materials
All materials,unless otherwise noted,were pur-chased from Aldrich and used as received.All monomers(?99%purity)were passed through a basic Al2O3chromatographic column(?ash). CuCl(Fisher;96%)was puri?ed by grinding and stirring with H2SO4(1N),followed by?ltration and successive washing with glacial acetic
acid
Figure 6.Cu
2
O/bpy-catalyzed LRP of MMA initiated with chlorosulfonyl calix-[n]arenes:(a)C4,n?4;(b)C6,n?6;and(c)C8,n?8.Reaction conditions:(a–c)
[MMA]?4.7M,90°C;(a,b)PhOPh,[MMA]/[O SO
2
Cl]/[Cu
2
O]/[bpy]?100/1/1/2molar
ratio;and(c)p-xylene,[MMA]/[O SO
2
Cl]/[Cu
2
O]/[bpy]?100/1/0.5/1molar
ratio.
Scheme10.Synthesis of a four-arm star PS by LRP initiated from STAR4and the
cleavage of its four PS arms.
4788PERCEC ET AL.
(four times),ethanol,and diethyl ether.The white CuCl powder was dried at 100°C for 30min and stored in an airtight bottle.Copper(I)oxide (?95%)was used as received from Alfa Characterization Techniques
1
H NMR (200MHz)and 13C NMR (50MHz)spec-tra were recorded on a Varian Gemini 200spec-trometer at 20°C in CDCl 3with tetramethylsi-lane as an internal standard.Melting points were determined with a Thomas–Hoover capillary melting-point apparatus and are uncorrected.High-pressure liquid chromatography (HPLC)and GPC analyses were obtained with a PerkinElmer series 10high-pressure liquid chro-matograph equipped with an LC-100column oven (40°C),a Nelson Analytical 900series integrator data station,a PerkinElmer 785A ultraviolet–vis-ible detector (254nm),and a Varian STAR 9040refractive index detector.The HPLC column was PL gel (5?m,100?),whereas for GPC,there were two columns of AM gel (10?m,500?and 10?m,104?).Tetrahydrofuran (THF;Fisher;HPLC-grade)was used as an eluent at a ?ow rate of 1mL/min.Relative M n ’s and M w ’s were deter-mined from calibration plots constructed with PS standards.
Typical Procedure for Polymerization Kinetics The monomer (MMA,2mL,18.7mmol),solvent (diphenyl ether,2mL),initiator (C4,53.1mg,
0.045mmol),catalyst (Cu 2O,23.6mg,0.16mmol),and ligand (bpy,50mg,0.32mmol)were weighted directly into a 25-mL Schlenk tube.The mixture was degassed by four freeze–pump–thaw cycles,?lled with Ar,and heated to the polymer-ization temperature.The side arm of the tube was purged with N 2for at least 5min before it was opened for the removal of samples at determined times with an air-tight syringe.Samples were diluted with CDCl 3in NMR tubes,and the con-version was measured by 1H NMR spectroscopy.Then,part of the solution was injected into a GPC column eluted with THF,and the molecular weight was measured versus PS standards with a UV detector (254nm)and versus PMMA stan-dards with a refractive index detector.In this case,the phenylsulfonyl chain end derived from the initiator was responsible for the UV absorp-tion.
Arm Cleavage of ATSC-Initiated PS
Three-arm star ATS(PS-Cl)3(30mg,1mmol,3mmol of SO 2,M n ?31,300,M w /M n ?1.42)was mixed in a test tube with potassium tert -butoxide (30mg,270mmol).The reagents were melted to a dark-brownish solid by the brief application (30s)of a hot-air gun.The residue was dissolved in CH 2Cl 2,washed with water,dried (MgSO 4),and evaporated to dryness.GPC analysis showed the product had M n ?11,500and M w /M n ?1.64.Heating the polymer without a base gave a mul-timodal product,M n ?13,400and M w /M n ?
3.01.
Figure 7.SEC traces for the Cu 2O/bpy-catalyzed,C8-initiated LRP of MMA.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS 4789
Arm Cleavage of STAR4-Initiated PMMA
STAR4-PMMA(500mg,5mmol,20mmol SO2, M n?104,250,M w/M n?1.16)was dissolved in25 mL of THF.At room temperature,NaOCH2CH3 (0.1g,2mmol)was added.The entire mixture was stirred for2h at room temperature.GPC analysis showed the product had M n?32,378 and M w/M n?1.11.
Arm Cleavage of STAR4-Initiated PS
STAR4-PS(500mg,5mmol,30mmol SO2,M n ?69,972,M w/M n?1.49)was dissolved in25mL of THF.At room temperature,NaOCH2CH3(0.1 g,2mmol)was added.The entire mixture was stirred for2h at room temperature.GPC analysis showed the product had M n?17,511and M w/M n ?1.46.
Financial support from ARO-MURI and NSF and an unrestricted faculty grant from DuPont are gratefully acknowledged.
REFERENCES AND NOTES
1.(a)Szwarc,M.Nature1956,178,1168;(b)Webster,
O.W.Science1991,251,887;(c)Szwarc,M.J Polym Sci Part A:Polym Chem1998,36,IX;(d) Otsu,T.J Polym Sci Part A:Polym Chem2000,38, 2121;(e)Webster,O.W.J Polym Sci Part A:Polym Chem2000,38,2855;(f)Deming,T.J.J Polym Sci Part A:Polym Chem2000,38,3011;(g)Jerome,R.;
Teyssie′,Ph.;Vuillemin,B.;Zundel,T.;Zune,C.J Polym Sci Part A:Polym Chem1999,37,1;(h) Kennedy,J.P.J Polym Sci Part A:Polym Chem 1999,37,2285;(i)Penczek,S.J Polym Sci Part A: Polym Chem2000,38,1919;(j)Inoue,S.J Polym Sci Part A:Polym Chem2000,38,2861.
2.Synthesis of Polymers;Schlueter,A.-D.,Ed;Wiley-
VCH:Weinheim,1999.
3.(a)Hadjichristidis,N.J Polym Sci Part A:Polym
Chem1999,37,857;(b)Angot,S.;Taton, D.;
Gnanou,Y.Macromolecules2000,33,5418;(c) Zhang,X.;Xia,J.;Matyjaszewski,K.Macromole-cules2000,33,2340;(d)Heise,A.;Nguyen,C.;
Malek,R.;Hedrick,J.L.;Frank,C.W.;Miller, R.D.Macromolecules2000,33,2346;(e)Matyjas-zewski,K.;Miller,P.J.;Pyun,J.;Kickelbick,G.;
Diamanti,S.Macromolecules1999,32,6526;(f) Heise,A.;Hedrick,J.L.;Trollsas,M.;Miller,R.D.;
Frank,C.W.Macromolecules1999,32,231;(g) Matyjaszewski,K.Macromolecules1998,31,4710;
(h)Angot,S.;Murthy,K.S.;Taton,D.;Gnanou,Y.
Macromolecules2000,33,7261.
4.(a)Fre′chet,J.M.J.;Henmi,M.;Gitsov,I.;
Aoshima,S.;Leduc,M.;Grubbs,R.B.Science1995,
269,1080;(b)Hawker,C.J.;Fre′chet,J.M.J.;
Grubbs,R.B.;Dao,J.J Am Chem Soc1995,117, 10763;(c)Grubbs,R.B.;Hawker,C.J.;Dao,J.;
Fre′chet,J.M.J.Angew Chem Int Ed Engl1997, 36,270;(d)Voit,B.J Polym Sci Part A:Polym Chem2000,38,2505;(e)Kim,Y.H.J Polym Sci Part A:Polym Chem2000,36,1685;(f)Sunder,A.;
Heinemann,H.;Frey,H.Chem Eur J2000,6,2499.
5.(a)Solomon,D.H.;Rizzardo,E.;Cacioli,P.U.S.
Patent4,581,429,1985;(b)Georges,M.K.;Vere-gin,R.P.N.;Kazmaier,P.M.;Hamer,G.K.Trends Polym Sci1994,2,66;(c)Hawker,C.J.J Am Chem Soc1994,116,11185;(d)Hawker,C.J.;Barclay,
G.C.;Dao,J.J Am Chem Soc1996,118,11467;(e)
Hawker,C.J.Trends Polym Sci1996,4,183;(f) Puts,R.D.;Sogah,D.Y.Macromolecules1996,29, 3323;(g)Catala,J.M.;Bubel,F.;Hammouch,S.O.
Macromolecules1995,28,8441;(h)Fukuda,T.;
Terauchi,T.Chem Lett1996,293.
6.For a series of kinetic investigations into metal-
catalyzed radical polymerizations initiated with al-kyl halides,see(a)Bamford, C.H.;Eastmond,
G.C.;Hargreaves,K.Nature1965,205,385;(b)
Bamford,C.H.;Hargreaves,K.Nature1966,209, 292;(c)Bamford,C.H.;Hughes,E.O.Proc R Soc London Ser A1972,326,489;(d)Otsu,T.;Yamagu-chi,M.;Takemura,Y.;Kusuki,Y.;Aoki,S.Polym Lett1967,5,697,835;(e)Otsu,T.;Yamaguchi,M.
J Polym Sci A-11969,7,387;(f)Iwatsuki,S.;Kasa-hara,H.;Yamashita,Y.Makromol Chem1967, 104,254.For the?rst claim of a metal-catalyzed LRP initiated with alkyl halides and the prepara-tion of block copolymers,see(g)Otsu,T.;Tazaki, T.;Yoshida,M.Chem Express1990,5,801.
7.(a)Kato,M.;Kamigaito,M.;Sawamoto,M.;Hi-
gashimura,T.Macromolecules1995,28,1721;(b) Matsuyama,M.;Kamigaito,M.;Sawamoto,M.J Polym Sci Part A:Polym Chem1996,34,3585. 8.(a)Wang,J.S.;Matyjaszewski,K.J Am Chem Soc
1995,117,5614;(b)Wang,J.S.;Matyjaszewski,K.
Macromolecules1995,28,7901.
9.Percec,V.;Barboiu,B.Macromolecules1995,28,
7970.
10.Percec,V.;Barboiu,B.;Neumann,A.;Ronda,J.C.;
Zhao,M.Macromolecules1996,29,3665.
11.(a)Barboiu,B.;Percec,V.Abstracts of the36th
IUPAC International Symposium on Macromole-cules,Seoul,Korea,Aug4–9,1996;p671;(b)Per-cec,V.;Barboiu,B.;Hill,D.H.Abstracts of the 36th IUPAC International Symposium on Macro-molecules,Seoul,Korea,Aug4O9,1996;p68;(c) Percec,V.;Barboiu,B.Polym Prepr(Am Chem Soc Div Polym Chem)1997,38,733.
12.Percec,V.;Kim,H.-J.;Barboiu,B.Macromolecules
1997,30,6702.
13.Percec,V.;Kim,H.-J.;Barboiu,B.Macromolecules
1997,30,8526.
14.Percec,V.;Barboiu,B.;Kim,H.-J.J Am Chem Soc
1998,120,305.
4790PERCEC ET AL.
15.(a)Percec,V.;Barboiu,B.;van der Sluis,M.Mac-
romolecules1998,31,4053;(b)van der Sluis,M.;
Barboiu,B.;Pesa,N.;Percec,V.Macromolecules 1998,31,9409.
16.Feiring,A.;Wonchoba,E.R.;Davidson,F.;Percec,
V.;Barboiu,B.J Polym Sci Part A:Polym Chem 2000,38,3313.
17.(a)Percec,V.;Asandei,A.D.;Asgarzadeh,F.;Bera,
T.K.;Barboiu,B.J Polym Sci Part A:Polym Chem 2000,38,3839;(b)Percec,V.;Asandei,A.D.;As-garzadeh,F.;Holerca,M.N.;Barboiu,B.;Grigoras,
C.J Polym Sci Part A:Polym Chem2000,38,4353.
18.(a)Curran,D.P.In Comprehensive Organic Syn-
thesis;Trost,B.M.,Ed.;Pergamon:Oxford,1991;
Vol4,pp715,779;(b)Motherwell,W.B.;Crich,D.
Free Radical Reactions in Organic Synthesis;Aca-demic:London,1992;(c)Minisci,F.Acc Chem Res 1975,8,165.
19.For representative examples of the Cu(I)-catalyzed
addition of sulfonyl chlorides to ole?ns,see(a)Ass-cher,M.;Vofsi, D.J Chem Soc1964,4962;(b) Orochov,A.;Asscher,M.;Vofsi,D.J Chem Soc B 1969,255;(c)Sinnreich,J.;Asscher,M.J Chem Soc Perkin Trans11972,1543;(d)Orochov,A.;Ass-cher,M.;Vofsi,D.J Chem Soc Perkin Trans21973, 1000;(e)da Silva Corre?a,C.M.M.;Waters,A.
J Chem Soc C1968,1874.
20.(a)Walling,C.Free Radicals in Solution;Wiley:
New York,1957;pp223–228;(b)Daiton,F.S.;Ivin, K.J.Nature1953,172,804;(c)Walling, C.;
Huyser,E.S.In Organic Reactions;Cope,A.C., Ed.;Wiley:New York,1963;Vol.13,p91.
21.For the UV-initiated addition of sulfonyl iodides to
acetylenes,see Truce,W.E.;Wolf,G.C.J Org Chem1971,36,1727.
22.For the peroxide-induced addition of sulfonyl chlo-
rides to ole?ns,see Kharash,M.S.;Zavist,A.F.
J Am Chem Soc1951,73,964.
23.For selected examples of the Cu(I)-catalyzed addi-
tion of sulfonyl chlorides and bromides to ole?ns,
see(a)Amiel,Y.Tetrahedron Lett1971,8,661;(b) Amiel,Y.J Org Chem1974,39,3867.
24.For selected examples of the Ru(II)-catalyzed addi-
tion of sulfonyl chlorides to ole?ns,see(a)Kami-gata,N.;Sawada,H.;Kobayashi,M.Chem Lett 1979,159;(b)Kamigata,N.;Sawada,H.;Koba-yashi,M.J Org Chem1983,48,3793;(c)Kamigata, N.;Ozaki,J.;Kobayashi,M.J Org Chem1985,50, 5045.For the Ru(II)-catalyzed addition of per?u-oroalkanesulfonyl chlorides to ole?ns with the ex-trusion of SO
2
,see(d)Kamigata,N.;Fukushima, T.;Terakawa,Y.;Yoshida,M.;Sawada,H.J Chem Soc Perkin Trans11991,627.
25.For reviews discussing the monoaddition of alkyl
halides to ole?ns and their telomerization,see(a) Walling,C.;Huyser,E.S.In Organic Reactions;
Cope,A.C.,Ed.;Wiley:New York,1963;Vol.13,p 91;(b)Freidlina,R.Kh.;Chukovskaya,E.C.Syn-thesis1974,477;(c)Freidlina,R.Kh.;Velichko,
F.K.Synthesis1977,145;(d)Curan,D.P.Synthe-
sis1988,417,489.
26.Grannel,C.;Dubois,Ph.;Jerome,R.;Teyssie′,Ph.
Macromolecules1996,29,8576.
27.(a)Haddleton,D.M.;Jasieczek,C.B.;Hannon,
M.J.;Shooter, A.J.Macromolecules1997,30, 2190;(b)Kajiwara,A.;Matyjaszewski,K.Polym J 1999,31,70.
28.(a)da Silva Corre?a,C.M.M.;Waters,W.A.J Chem
Soc C1968,1874;(b)Kice,J.L.;Pawlowsky,N.E.
J Am Chem Soc1964,86,4898;(c)Bennett,J.E.;
Brunton,G.;Gilbert,B.C.;Whittall,P.E.J Chem Soc Perkin Trans21988,1359;(d)Iino,M.;Mat-suda,M.J Org Chem1983,48,3108.
29.(a)Fischer,H.J Am Chem Soc1986,108,3925;(b)
Daikh,B.;Finke,R.E.J Am Chem Soc1992,114, 2938;(c)Fischer,H.J Polym Sci Part A:Polym Chem1999,37,1885.
30.Percec,V.;Bera,T.K.;De,B.B.;Sanai,Y.;Smith,
J.;Holerca,M.H.;Barboiu,B.;Grubbs,R.B.;Fre′-chet,J.M.J.To be submitted for publication.
AROMATIC MULTISULFONYL CHLORIDE INITIATORS4791
摘要：本文主要使用了百度、谷歌等搜索引擎和Web of science数据库对包信和院士的研究内容及其研究成果进行了分析，通过百度、谷歌、个人主页对包信和院士的基本信息进行了解；通过Web of science数据库对包信和院士的研究方向、引文数据、合作者、基金资助机构、出版物进行了了解。并对其2014年5月的一篇文章进行了深入的分析。 一、基本信息 包信和，理学博士，研究员，博士生导师、中科院院士、物理化学家，中国科学院大连化学物理研究所研究员，现任中科院沈阳分院院长，复旦大学常务副校长，兼任中国科学技术大学化学物理系主任。 他的个人工作经历为： 1989年至1995年获洪堡基金资助，在德国马普学会Fritz-Haber研究所任访问学者，1995年应聘回国。 1995年至2000年在中科院大连化学物理研究所工作。 2000年8月至2007年3月任大连化学物理研究所所长。 2003年3月起任中国科技大学化学物理系系主任。 2009年3月起任沈阳分院院长。 2009年当选为中国科学院院士。 2015年9月经教育部研究决定，任命包信和为复旦大学常务副校长 其次在大连化学物理研究所的个人介绍和包信和院士的课题组主页里搜集了对其研究方向的简介： 包信和研究员主要从事表面化学与催化基础和应用研究。发现次表层氧对金属银催化选择氧化的增强效应，揭示了次表层结构对表面催化的调变规律，制备出具有独特低温活性和选择性的纳米催化剂，解决了重整氢气中微量CO造成燃料电池电极中毒失活的难题。发现了纳米催化体系的协同限域效应，研制成碳管限域的纳米金属铁催化剂和纳米Rh-Mn催化剂，使催
化合成气转化的效率成倍提高。在甲烷活化方面，以分子氧为氧化剂，实现了甲烷在80℃条件下直接高效氧化为甲醇的反应；创制了Mo/MCM-22催化剂，使甲烷直接芳构化制苯的单程收率大幅度提高。 二、研究成果分析 利用Web of Science搜索包老师的文章，总共搜索到497篇文章，对检索报告创建引文报告，如图2.1所示。文章被引总频次达到12804次，平均每篇文章被引25.76次，h-index值为56，表示在包老师所发的文章中，每篇被引用了至少56次的论文总共有56篇左图为每年出版的文献数图标，2000年以来，每年出版的文献数量基本稳定，在30篇左右，研究状态保持稳定。其中2015年发表文章篇数最高，2015年是个高产年。 根据每年的引文数图标可以看出，每年的引文数不断上升，表明其发表的文章是有生命力、有价值的。也表明每年发文的质量不断在上涨。 图2.1创建引文报告 对检索结果进行分析。图2.2是对作者进行分析，得到如下图所示的结果，可以看到合作者的信息，其中与293名作者有过合作。其中合作最多的为韩秀文老师（大连化物所）、马丁老师(北京大学)。
Web of Science 数据库的检索与利用 解放军医学图书馆杜永莉 一、引文检索概述 （一）基本概念 1. 引文（Citation）：文献中被引用、参考的文献(Cited Work),也称施引文献，其作者称为被引著者（Cited Author）。 2. 来源文献（Source）：提供引文的文献本身称为来源文献，其作者称为引用著者（Citing Author）。 3. 引文索引（Citation Index）：通过搜集大量来源文献及其引文，并揭示文献之间引用与被引用关系的检索工具。 4. 引文检索：是以被引用文献为检索起点来查找引用文献的过程。 （二）引文的历史回顾 引文的创始人Dr.Eugene Garfield博士是美国科学信息研究所（ISI）的创始人，现在仍然是科学信息研究所的名义董事长，还是美国信息科学协会的前任主席、The Scientist 董事会的主席、Research America董事会的成员。另外他还是文献计量学的创始人。 Dr.Garfield于1955年在Science上发表了具有化时代意义的学术论文：“Citation Indexes for Science: A New Dimension in Documentation through Association of Ideas.”他在这篇文章中描述科研人员可以利用引文加速研究过程、评估工作影响、跟踪科学趋势；阐明引文是学术研究中学术信息获取的重要工具。1957 他创建了美国科学信息研究所(Institute for Scientific Information， ISI)。
1961 年， ISI 推出了 Science Citation Index ， SCI 。一种5卷印刷型刊物，包括613种期刊140万条引文的索引。1966年，ISI发布磁带形式的数据，1989年推出CD-ROM 光盘版，1992年ISI为汤姆森科技信息集团接管（Thomson Scientific），1997年推出系列引文数据库（Web of Science)，2001年建立具有跨库检索功能的（ISI Web of Knowledge）。 20世纪30年代中期，另外一个著名计量学家布拉德福（S.C.Bradford)在对大量的期刊分布进行研究之后，得出了布拉德福定律(二八定律），揭示出各学科核心期刊的存在，这些核心期刊组成了所有学科的文献基础,重要论文会发表在相对较少的核心期刊上；因此从文献学的角度,没有必要将已经出版的所有期刊全部收录，从数据库的质量上说，则需要有一套科学的流程筛选高质量期刊，为读者提供高质量的学术信息。 Garfield 博士从建立引文数据库开始，经过几十年的时间，建立了一整套期刊筛选的工作流程，每年从全球出版的学术期刊中，筛选出各学科中质量高、信息量大、使用率高的核心期刊。由于这套流程对期刊一些客观指数的长期跟踪，衍生出了另外两个数据库：期刊引证报告（Journal Citation Reports，JCR)和基本科学计量指标（Essential Science Indicators）。 （三）引文的作用 了解某一课题发生、发展、变化过程；查找某一重要理论或概念的由来；跟踪当前研究热点；了解自已以及同行研究工作的进展；查询某一理论是否仍然有效，而且已经得到证明或已被修正；考证基础理论研究如何转化到应用领域；评估和鉴别某一研究工作在世界学术界产生的影响力；发现科学研究新突破点；了解你的成果被引用情况；引文检索为科研人员开辟了一条新颖、实用的检索途径；同时为文献学、科学学、文献计量学等分析研究提供参考数据，如衡量期刊质量、测定文献老化程度、观察学科之间的渗透交叉关系、评价科研人员的学术水平，引文数据库是不可缺少重要工具。 二、Web of Science的检索途径 （一）科学引文索引简介
1、引文的创始者是（A） A、Eugene Garfield B、S.C.Bradford C、Billings,S.A D、Harris,C.J 2、引文的创始单位是（A） A、ISI B、NLM C、CDC D、NIH 3、ISI推出系列引文数据库（Web of Science）的时间是（D ） A、1956年 B、1989年 C、1990年 D、1997年 4、SCI的局限性不包括（B ） A、主要限于基础科学方面 B、不能囊括多数国际多学科高质量科学期刊 C、收录第三世界国家期刊较少 D、论文被引用情况复杂 5、ISI推出了SCI的时间（C） A、1950年 B、1955年 C、1961年 D、1970年 6、关于引文的作用，以下说法错误的是（D ） A、了解某一课题发生、发展、变化过程 B、引文检索为科研人员开辟了一条新颖、实用的检索途径 C、为文献学、科学学、文献计量学等分析研究提供参考数据 D、直接查找全文数据 7、Web of Knowledge包含的数据库有（D） A、Web of Science B、科学会议录索引、化学反应数据库 C、化学索引数据库、Medline数据库 D、以上皆是 8、关于Web of Science的特点，以下说法错误的是（D ） A、跨学科、精选内容，可以进行引文检索
B、增加了分析、跟踪、写作和管理功能 C、从文献相互关系的角度，提供新的检索途径 D、从著者、标题、分类等角度提供检索途径 9、ISI推出CD-ROM光盘版的时间是（A ） A、1970年 B、1961年 C、1982年 D、1991年 10、在SCI中公共卫生所在的数据库是（B ） A、Web of Science Expanded B、Social Sciences Citation Index C、Arts & Humanities Citation Index D、其他
Web of Science系统 在科技发展与竞争力 分析中应用 周宁丽 2012.10
内容提纲 1.WOS及其功能简介 2.科技文献检索以及分析概念与术语 3.WOS文献检索功能及其利用 4.WOS文献分析功能及其应用 5.WOS引文分析功能及其应用
1. WOS 及其功能简介 ?WOS 简介 WOS（Web of Science)数据库是汤森路透科技集团创建的WOK（ISI web of Knowledge）信息平台中的一个系统。 ?WOS 数据资源 3个引文数据库：Science Citation Index Expanded (SCI-EXPANDED) --1900-至今 （涵盖8,200种核心期刊） Social Sciences Citation Index (SSCI) --1996-至今（涵盖2,800种核心期刊） Conference Proceedings Citation Index -Science (CPCI-S) --1990-至今（涵盖60,000个会 议录） 1个化学数据库: Current Chemical Reactions (CCR-EXPANDED) --1986-至今 ?WOS 主要功能 1.收录、引用、主题文献检索 2.文献与引文统计分析 3. 文献管理与跟踪 ?WOS 学科领域 （1）自然科学、工程技术、生物医 学等150 多个学科领域 （2）人文社科50多个学科领域
2. 1 科技文献收引检索概念 ?科技论文收录检索 选用权威的文献检索系统（如：WOS、ISTP、EI、PUMED、 SCOPAS、CSCD、CSSCI），对其数据库系统收录所发表的期刊、会议文献进行检索 ?科技论文引文检索 利用权威的文献检索系统（如：WOS、ISTP、EI、PUMED、 SCOPAS、CSCD、CSSCI），对其数据库系统收录的期刊、会议文献的引用频次进行查询，对其引文进行检索 ?课题（主题）文献检索 利用权威的文献检索系统（如：WOS、ISTP、EI、PUMED、 SCOPAS、CSCD、CSSCI），对某学科、研究主题进行相关文献检索
web of Science数据库几个标识（DOI、UT、IDS Number、ISSN、ISBN）的含义 无论是检索机构还是文章作者，对于web of Science数据库记录格式中出现的DOI、UT、IDS Number、ISBN ISSN等英文标识不尽了解，经咨询ＩＳＩ公司及相应的检索后，把这些标识的意思做简要说明。 （1）DOI（Digital Object Unique Identifier）：对象唯一标识符 传统方式是采用URL对因特网上数字资源进行标识，用户点击URL链接即可访问对应的数字资源。然而URL所代表的只是数字资源的物理位置，并不是数字资源本身，一旦资源的物理位置发生变化，原来的URL将成为―死链‖。因此，仅仅使用URL来代表数字对象和链接已经不能适应分布式动态环境的要求。数字对象唯一标识符（Digital Object Unique Identifier）由此产生，它并非只是一个不重复的字符串，真正有用的唯一标识标符系统应该是一套包括名称空间、唯一标识符、命名机构、命名登记系统和解析系统5 个部分的完整体系。 简要地说，对所标识的数字对象而言，DOI相当于人的身份证，具有唯一性。保证了在网络环境下 对数字化对象的准确提取，有效地避免重复。一个网络对象（各种数字资源）一个编号例如——DOI:10.1134/S1061920808010020 （2）UT（Unique Article Identifier）是文章的唯一识别符——收录号 UT –Unique Article Identifier字段是ISI (现在公司名称Thomson Reuters)分配给一篇文章的唯一识别符。可以唯一地识别一条参考文献。它没有显示在Web of Science文章的全记录页里，当输出记录保存为HTML格式时，可以看到UT字段文章的唯一标识符。一篇文章一个编号 例如——UT ISI:000259889100041 （3）IDS Number——检索号 Thomson Reuters Document Solution? 编号。此号码是识别期刊和期号的唯一编号，用于订阅Document Solution 中的文献的全文。一本期刊每一期发表的文章都是一个IDS号。一个期刊的一期对应一个编号 例如——IDS Number:358AR （4）ISSN 国际标准期刊号(International Standard Serial Number)，是标识定期出版物（如期刊）和电子出版物的唯一编号，共八位。一个期刊一个编号 （5）ISBN 国际标准书号(International Standard Book Number) 是一种机器读取的唯一标识符，可准确无误地标识书籍。 例如——ISBN：7-5023-4424-1
Web of Science (SCIE,SSCI,AHCI,CPCI) 登录https://www.doczj.com/doc/cd8068231.html, 资源简介： Web of Science 是汤森路透科技集团（Thomson Reuters）的产品，Web of Science 包括著名的三大引文索引数据库(SCIE,SSCI,A&HCI)。本馆开通试用的数据库如下： 科学引文索引（Science Citation Index Expanded，简称SCIE），被公认为世界范围最权威的科学技术文献的索引工具，能够提供科学技术领域最重要的研究成果。提供8600多种涵盖176 个学科的世界一流学术科技期刊的文献信息。 社会科学引文索引（Social Sciences Citation Index，简称SSCI），收录3100多种涵盖56个学科的世界一流学术性社会科学期刊的文献信息。 艺术与人文引文索引（Arts & Humanities Citation Index，简称A&HCI），收录艺术与人文学科领域内1,600多种学术期刊，数据可回溯至1975年。同时还从Web of Science 收录的8,000多种科技与社会科学期刊中，筛选出与艺术人文相关的学术文献。 会议论文引文索引（Conference Proceedings Citation Index，简称CPCI），汇聚了全球最重要的学术会议信息，包括专著、丛书、预印本以及来源于期刊的会议论文，提供了综合全面、多学科的会议论文资料。其内容分为两个版本：Conference Proceedings Citation Index - Science (CPCI-S，原ISTP）；Conference Proceedings Citation Index - Social Science & Humanities (CPCI-SSH，原ISSHP）。 Web of Science (SCIE,SSCI,A&HCI,CPCI)数据库的特色 利用Web of Science可以快速检索科研信息，可以全面了解有关某一学科、某一课题的研究信息。在提供文献的书目与文摘信息的同时，Web of Science(SCIE,SSCI,AHCI,CPCI)设置了"引文索引"（Citation Index），提供该文献所引用的所有参考文献信息以及由此而建立的引文索引，揭示了学术文献之间承前启后的内在联系，帮助科研人员发现该文献研究主题的起源、发展以及相关研究。还可通过Email和RSS定制主题及引文跟踪服务，随时把握最新研究动态,跟踪国际学术前沿。 Web of Science收录各学科领域中权威、有影响力的期刊，由于其严格的选刊标准和引文索引机制，使得Web of Science(SCIE,SSCI,AHCI,CPCI)在作为文献检索工具的同时，也成为文献计量学和科学计量学的最重要基本评价工具之一。 免费学习资源： 数据库使用指南下载：https://www.doczj.com/doc/cd8068231.html,/productraining/
点击查看更多应用技巧 应用技巧 1.1怎样了解某研究课题的总体发展趋势？ 检索结果告诉我们找到了152篇“侯建国”院士的文章。（如果有重名的现象，请参考我们随后提供的有关作者甄别工具的应用技巧。） 1．访问Web of Science数据库检索论文 请访问：https://www.doczj.com/doc/cd8068231.html,，进入ISI Web of Knowledge平台；选择Web of Science数据库，(以下图示为WOK4.0版新界面)。 示例：如果我们希望检索“中国科技大学”“侯建国”院士在Science Citation Index (SCI)中收录文章的情况。 2．生成引文报告 在检索结果界面上，通过右侧的生成引文报告功能，您可以快速了解该课题的总体研究趋势，并且找到本课题的国际影响力年代变化情况。
结论：通过Web of Science提供的强大的引文报告功能，您可以点击创建引文报告，自动生成课题引文报告，从而提高您的科研效率。 3 利用分析功能了解课题发展趋势 除了自动创建引文报告之外，您也可以利用分析功能生成论文出版年的图式。并且，利用分析功能您可以任意查看某些出版年的论文情况。
结论：通过Web of Science提供的强大的引文报告功能，您可以点击创建引文报告，自动生成课题引文报告，对总体趋势一览全局。而分析功能可以让您更清晰的了解本课题论文每年的发文量，分属于哪些学科，主要集中在哪些国家地区，以哪些语种发表，哪些机构或哪些作者是本课题的引领者，收录本课题论文最多的期刊和会议有哪些等详细信息。
点击查看更多应用技巧 应用技巧 1.2 如何找到某个课题的综述文献？ 在科学研究过程中往往需要从宏观上把握国内外在某一研究领域或专题的主要研究成果、最新进展、研究动态、前沿问题或历史背景、前人工作、争论焦点、研究现状和发展前景等内容，如何快速获取这些信息呢？您可以通过检索综述性文献来方便高效地找到信息。 1．访问Web of Science数据库检索课题 请访问：https://www.doczj.com/doc/cd8068231.html,，进入ISI Web of Knowledge平台；选择Web of Science数据库。如：我们想快速找到有关2007年诺贝尔物理奖获奖课题“巨磁电阻效应-Giant Magnetoresistance”的综述文献。 2．精炼检索结果 在检索结果界面上，通过左侧的精炼检索结果功能您可以快速的了解该课题涉及的学科、文献类型、作者、机构、国家等，甚至通过文献类型选项锁定该课题的高质量综述文献。