探针

Supporting InformationRemarkable ESIPT induced NIR Emission by a Selective Colorimetric Dibenzimidazolo Diimine Sensor for Acetate Shyamaprosad Goswami *a, Sibaprasad Maity a,b,Avijit kumar Das a, Annada C Maity a,Tarun Kanti Mandal b, Siddhartha Samanta ba Department of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah-711103,West Bengal, India, Fax: +91-3326682916. spgoswamical@b Haldia Institute ofTechnology, Hatiberia, Haldia, West Bengal-721657CONTENT Page1.General (2)2.General methods of UV-vis and fluorescence titration experiments (2)3.Association constant determination, job plot …………………..………………………2-34.Quantum yield and detection limit determination (4)5.Procedure for the preparation of Sensor and its spectroscopic characterization( 1H NMR, 13C, and Mass)…………………………………………………………………5-86.Fluorescence titration spectra of DDS with different guest anions………..…………….9-107. UV-vis titration spectra of DDS with different guest anions........................….............. 10-128. Optimized Structures………………………………………………………………………..12-169. Structural parameters and Mulliken Charges…………………………….……………..17-1810. HOMO -LUMO transitions, compositions, vertical excitation and oscillator strength..18-1911.Theoretical Calculation for Shorter Emission (19)12. 11.Theoretical Calculation for Longer Emission (20)1. General:The chemicals and solvents were purchased from Sigma-Aldrich Chemicals Private Limited and were used without further purification. Melting points were determined on a hot-plate melting point apparatus in an open-mouth capillary and were uncorrected. 1H-NMR and 13C NMR spectra were recorded on Brucker 400 MHz instruments. NMR titration was carried out in d 6- DMSO solvent on 400 MHz instrument. For NMR spectra, DMSO was used as solvent with TMS as an internal standard. Ch emical shifts are expressed in δ units and 1H –1H and 1H –C coupling constants in Hz. UV-vis titration experiments were performed on a JASCO UV-V530 spectrophotometer and fluorescence experiment was done using PerkinElmer LS 55 fluorescence spectrophotometer with a fluorescence cell of 10 mm path.2. General method of Uv-vis and fluorescence titrations:For Uv-vis and fluorescence titrations, stock solution of the sensor was prepared (c = 1× 10-5 ML-1) in CH 3CN. The solution of the guest anion like tetrabutyl ammonium acetate was prepared (2 × 10-4 ML-1) in CH 3CN. The original volume of the DDS solution was 2 ml.Solutions of the sensor of various concentrations and increasing concentrations of anions were prepared separately. The spectra of these solutions were recorded by means of Uv-vis methods.Association constant determination using Uv-vis spectra:Binding constant was calculated according to the Benesi-Hildebrand equation. K a was calculated following the equation stated below.1/(A-A o ) = 1/{K(A max –A o ) [AcO -]n } + 1/[Amax-A o ] Here A o is the absorbance of receptor in the absence of guest, A is the absorbance recorded in the presence of added guest, Amax is absorbance in presence of added [AcO -]max and K is the association constant (M -1). The association constant (K) could be determined from the slope of the straight line of the plot of 1/(A-A o ) against 1/[AcO -]n . The association constant (K a ) as determined by UV-vis titration method for sensor with AcO - is found to be 3 x 104 M -1.Figure S 1: Benesi –Hildebrand plot from UV-vis titration data of DDS (c = 1x10-5M) with AcO -(c = 2x10-4M).51/(A -A 0)1/[AcO -]General procedure for drawing Job plot by UV –vis method:Stock solution of same concentration of DDS and AcO - were prepared in the order of ≈ 2.0 x 10-5 M in pure CH 3CN. The absorbance in each case with different host –guest ratio but equal in volume was recorded. Job plots were drawn by plotting ΔI.X host vs X host (ΔI = change of intensity of the absorbance spectr um during titration and X host is the mole fraction of the host in each case, respectively).Fig-S 2: Jobs plot diagram of DDSAssociation constant determination using fluorescence spectra:The binding constant value of AcO - with DDS has been determined from the emission intensity data following the modified Benesi –Hildebrand equation, 1/∆I = 1/∆I max + (1/K[C]) (1/∆I max). Here ∆I = I-Imin and ∆I max = I max -I min , where I min , I and I max are the emission intensities of sensor considered in the absence of AcO -, at an intermediate AcO - concentration and at a concentration of complete saturation where K is the binding constant and [C] is the AcO - concentration respectively. From the plot of 1/(I-I min ) against [C]-1 for sensor, the value of K has been determined from the slope. The association constant (K a ) as determined by fluorescence titration method for sensor with AcO -is found to be 1.7 x 104 M -1 (error < 10%).Fig. S 3: Benesi –Hildebrand plot from fluorescence titration data of DDS (c =1x10-5M) with AcO - (c = 2x10-4M).I .X h1/(I -I m i n )1/[AcO -]3. Determination of fluorescence quantum yield:Here, the quantum yield φ was measured by using the following equation, φx = φs ( F x / F s )( A s / A x )(n x 2/ n s 2)Where,X & S indicate the unknown and standard solution respectively, φ = quantum yield, F = area under the emission curve, A = absorbance at the excitation wave length,n = index of refraction of the solvent. Here φ measurements were performed using anthracene in ethanol as standard [φ = 0.27] (error ~ 10%)4. Calculation of the detection limit:The detection limit (DL) of DDS in absorption and emission spectra for AcO - was determined from the following equation 1: DL = K* Sb1/SWhere K = 2 or 3 (we take 3 in this case); Sb1 is the standard deviation of the blank solution; S is the slope of the calibration curve.From the graph Fig.S 4(a), we get slope = 0.0052, and Sb1 value is 0.01283.Thus using the formula we get the Detection Limit for AcO - = 7.4 µM in Uv-vis absorption spectra. From the graph Fig.S 4(b), we get slope = 8.745, and Sb1 value is 18.388.Thus using the formula we get the Detection Limit for AcO - = 6.3 µM in Fluorescence spectra.Fig. S 4 (a) Changes of absorbance of DDS (c = 1x10-5M) as a function of [ACO -](c = 2x10-4M) at 566 nm. (b) Changes of Fluorescence Intensity of DDS (c=1x10-5M) as a function of [AcO -] (c = 2x10-4M) at 638 nm.Ref.1: Zhu, M.; Yuan, M.; Liu, X.; Xu, J.; Lv, J.; Huang, C.; Liu, H.; Li, Y.; Wang, S.; Zhu, D. Org. Lett. 2008, 10,1481-1484.F l u o r e s c e n t I n t e n s i t y[AcO -]/μMA b s o r b a n c e[AcO -]/μM5. a) Methods for the preparation of DDS:i) Synthesis of 2-hydroxy-5-methyl-benzene-1,3-dicarbaldehyde (2):As we learnt, p-Cresol (10 g) was added to a solution of NaOH (3 g) in water (20 mL). Following full development of a gold color, 37% formaldehyde (20 g) was added. The mixture was stirred for 20 min and allowed to stand overnight at the ambient temperature. The yellow granular 2,6-dimethylol-5-methylphenol product was collected by vacuum filtration and washed with water-saturated sodium chloride followed by dilute HCl. In a 100 ml r.b. flask fitted with a reflux condenser, a magnetic stirrer and a dropping funnel was placed 2,6-dimethylol-5-methylphenol (1 gm). Following addition of excess MnO2, it was then refluxed in CHCl3 for 18 hours. Finally, the product 2was purified by 60-120 silica gel by 5% ethyl acetate in pet ether. Yield of the product was 500 mg (50%).ii) Synthesis of the DDS:The amine 3 (266 mg, 2 mmol) and dicarbaldehyde 2(164 mg, 1 mmol) were refluxed in dry ethanol (20 mL) for 4h. A yellow precipitate was separated out, filtered and washed with ethanol. The yellow solid product was recrystallized in absolute ethanol giving the yellow solid compound DDS in 80% yield. Yield of the product- 350 mg. Melting point:162°C.1H NMR (DMSO-d, 400 MHz):δ (ppm): 12.79 (s, 1H), 9.70 (s, 2H), 7.97 (s, 2H), 7.53(s, 4H), 7.186(dd, 4H, J= 6 Hz), 2.35 (s, 3H ).ESI (m/z, %):M+ Calculated for C23H18N6O is 394.15; Found: 395.26 (M+H)+; 417.20 (M+Na)+.13C NMR(DMSO-d, 100 MHz):δ(ppm): 163.19, 160.66, 155.32, 154.73, 140.14, 135.97, 129.25,6128.84, 122.71, 119.77, 111.95, 49.06, 20.38.b) 1H NMR spectrum of DDS:Figure: S5b) 13C NMR spectrum of DDS:Figure: S6c) Mass Spectra of DDS:Figure: S76. Fluorescence spectra of DDS with different guest anions in acetonitrile:5006007008001020304050Cl-F l u o r e s c e n c e I n t e n s i t yWavelength(nm)4505005506006507007508001020304050I-F l u o r e s c e n c e I n t e n s i t yWavelength(nm)5006007008001020304050Br-F l u o r e s c e n c e I n t e n s i t yWavelength(nm)5006007008001020304050BenzoateF l u o r e s c e n c e I n t e n s i t yWavelength(nm)5006007008001020304050F-F l u o r e s c e n c e I n t e n s i t yWavelength (nm)4505005506006507007508001020304050PhosphateF l u o r e s c e n c e I n t e n s i t yWavelength(nm)Figure: S 87. UV-vis absorption spectra of DDS with different guest anions in acetonitrile:3004005006007000.00.10.20.30.40.50.60.7BenzoateA b s o r b a n c eWavelength (nm)5006007008001020304050NitrateF l u o r e s c e n c e I n t e n s i t yWavelength(nm)3004005006007000.00.10.20.30.40.50.60.7SulphiteA b s o r b a n c eWavelength (nm)5006007008001020304050NitriteF l u o r e s c e n c e I n t e n s i t ywavelength(nm)500600700800010********Sulphite F l u o r e s c e n c e I n t e n s i t yWavelength (nm)5006007008001020304050DHPF l u o r e s c e n c e I n t e n s i t yWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7DHPA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7PhosphateA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7NitrateA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7NitriteA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7FluorideA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7ChlorideA b s o r b a n c eWavelength (nm)Figure:S 98. Computational Study:The ground state geometry (S o ) of DDS and it’s tautomers were optimized using the tight criteria in solvent phase using Density Functional Theory (DFT).The functional used was B3LY P.The basis set used for all atoms were 6-31+G(d,p). The vibrational frequencies at the optimized structure corresponds to local minima on the energy surface. The vertical excitation energies at the ground state equilibrium geometries were calculated with TD-DFT.The low-laying first singlet excited state (S 1) of each tautomer were relaxed using the TD-DFT to obtain the minimum energy geometry .The difference energy between the optimized geometry at first singlet excited state and ground state was used in computing the emission.All the computation in acetonitrile solvent were carried out using the Polarizable Continuum Model (PCM). All electronic structure computations were carried out using the Gaussian 09 program.B3LYP optimized structure:Cartesian Coordinates 1. E nol (Solvent Phase).B3LYP optimized structure3004005006007000.00.10.20.30.40.50.60.7IodideA b s o r b a n c eWavelength (nm)3004005006007000.00.10.20.30.40.50.60.7BromideA b s o r b a n c eWavelength (nm)Figure:S10Energy(B3LYP)= -1291.157843 a.uTable S1:---------------------------------------------------------------------- Center Atomic Atomic Coordinates (Angstroms)Number Number Type X Y Z---------------------------------------------------------------------1 6 0 -1.209825 3.382647 0.0004532 6 0 -1.185238 1.974481 0.0002233 6 0 0.079290 1.323253 0.0001044 6 0 1.264770 2.114395 0.0002245 6 0 1.168204 3.521411 0.0004486 6 0 -0.058431 4.180191 0.0005677 1 0 -2.182774 3.868887 0.0005438 1 0 2.089770 4.098491 0.0005429 6 0 -0.155927 5.688207 0.00079910 1 0 0.836212 6.147028 0.00111211 1 0 -0.694803 6.050838 -0.88155812 1 0 -0.695225 6.050539 0.88302013 6 0 2.577295 1.508854 0.00015014 1 0 3.442663 2.176238 0.00023815 6 0 -2.481126 1.307891 0.00012016 1 0 -3.338057 1.990578 0.00026417 8 0 0.151497 -0.011795 -0.00013918 7 0 2.737432 0.217701 0.00004819 7 0 -2.677754 0.030111 -0.00012220 6 0 4.011317 -0.319781 0.00002621 6 0 6.125607 -0.692002 0.00004622 6 0 5.497455 -1.966566 -0.00010623 1 0 3.380264 -2.348348 -0.00019824 6 0 7.526638 -0.605608 0.00009525 6 0 6.221423 -3.162369 -0.00021326 6 0 8.254124 -1.793890 -0.00001027 1 0 8.021257 0.360838 0.00021228 6 0 7.611819 -3.052880 -0.00016229 1 0 5.728226 -4.129159 -0.00033030 1 0 9.339360 -1.755773 0.00002431 1 0 8.214765 -3.955847 -0.00024132 6 0 -5.558020 -1.992285 -0.00043133 1 0 -3.460513 -2.474150 -0.00061334 6 0 -6.121201 -0.687044 -0.00013735 6 0 -6.342141 -3.149591 -0.00063736 6 0 -7.516435 -0.531149 -0.00004537 6 0 -7.725671 -2.970884 -0.00054238 1 0 -5.898434 -4.140141 -0.00086239 6 0 -8.303558 -1.681219 -0.00025040 1 0 -7.961882 0.459076 0.00018041 1 0 -8.373166 -3.842549 -0.00069542 1 0 -9.385568 -1.588213 -0.00018543 7 0 -4.195350 -1.780237 -0.00044444 7 0 -5.119166 0.268359 0.00002045 6 0 -3.986486 -0.419676 -0.00016947 7 0 4.145506 -1.687856 -0.00011648 1 0 1.122398 -0.260821 -0.000246 -----------------------------------------------------------------------Cartesian Coordinates 2. Keto (Solvent Phase).B3LYP optimized structureFigure:S11Energy(B3LYP)=-1291.1525911 a.uTable S2:---------------------------------------------------------------------- Center Atomic Atomic Coordinates (Angstroms)Number Number Type X Y Z---------------------------------------------------------------------1 6 0 -1.225118 3.351374 -0.0000712 6 0 -1.193655 1.956309 -0.0000123 6 0 0.098893 1.275016 0.0000734 6 0 1.281123 2.146125 0.0000125 6 0 1.151922 3.564531 -0.0000326 6 0 -0.079973 4.185144 -0.0000707 1 0 -2.202291 3.831793 -0.0001118 1 0 2.060434 4.162972 -0.0000529 6 0 -0.231023 5.687936 -0.00011410 1 0 0.744347 6.181691 -0.00027911 1 0 -0.783409 6.032071 -0.88211512 1 0 -0.783145 6.032147 0.88202613 6 0 2.567724 1.590926 0.00001814 1 0 3.449914 2.224818 0.00004315 6 0 -2.481279 1.286864 -0.00001216 1 0 -3.341519 1.966581 -0.00005218 7 0 2.777558 0.273840 -0.00003419 7 0 -2.682507 0.006300 0.00004020 6 0 4.027869 -0.323334 -0.00002421 6 0 6.131503 -0.698854 -0.00000422 6 0 5.500300 -1.968829 -0.00001223 1 0 3.384493 -2.359008 -0.00002724 6 0 7.530777 -0.614797 0.00000925 6 0 6.217242 -3.166896 -0.00000626 6 0 8.254796 -1.806366 0.00001627 1 0 8.027833 0.350211 0.00001328 6 0 7.609023 -3.061982 0.00000929 1 0 5.720258 -4.131577 -0.00001230 1 0 9.340027 -1.771152 0.00002731 1 0 8.208292 -3.967260 0.00001432 6 0 -5.573235 -2.001199 0.00012433 1 0 -3.477541 -2.491807 0.00032734 6 0 -6.130308 -0.693327 -0.00008735 6 0 -6.362241 -3.154714 0.00022536 6 0 -7.524728 -0.531908 -0.00020537 6 0 -7.745668 -2.970583 0.00010638 1 0 -5.922714 -4.147192 0.00038739 6 0 -8.317535 -1.678762 -0.00010540 1 0 -7.966149 0.460206 -0.00036741 1 0 -8.396701 -3.839647 0.00017842 1 0 -9.399141 -1.580545 -0.00019143 7 0 -4.209343 -1.794863 0.00018744 7 0 -5.123997 0.257846 -0.00014445 6 0 -3.992682 -0.434674 0.00002146 7 0 5.177772 0.312488 -0.00001647 7 0 4.141949 -1.688937 -0.00002848 1 0 1.884927 -0.268202 -0.000140 --------------------------------------------------------------------- Cartesian Coordinates 3. Enol Acetate complex (Solvent Phase).B3LYP optimized structureFigure:S12Energy(B3LYP)=-1519.8173047 a.uTable S3:--------------------------------------------------------------------- Center Atomic Atomic Coordinates (Angstroms)Number Number Type X Y Z---------------------------------------------------------------------1 6 0 -1.219882 4.285934 0.0215922 6 0 -1.220479 2.881526 0.0101113 6 0 0.035108 2.207110 0.0040194 6 0 1.244639 2.965775 0.0094885 6 0 1.173097 4.374074 0.0214456 6 0 -0.044379 5.054289 0.0276447 1 0 -2.181388 4.795625 0.0259938 1 0 2.103127 4.938002 0.0258389 6 0 -0.108404 6.564987 0.04027810 1 0 0.893926 7.001599 0.04361011 1 0 -0.639126 6.948384 -0.83853812 1 0 -0.638536 6.933624 0.92573913 6 0 2.528514 2.292857 0.00308114 1 0 3.437217 2.901314 0.00840615 6 0 -2.497614 2.171644 0.00427916 1 0 -3.396091 2.802150 0.00772917 8 0 0.064601 0.881629 -0.00712218 7 0 2.579393 0.993599 -0.00893119 7 0 -2.571301 0.884131 -0.00454720 6 0 3.744293 0.260439 -0.01454521 6 0 5.755592 -0.475101 -0.01598522 6 0 4.903540 -1.615791 -0.03175723 1 0 2.725907 -1.621523 -0.03792424 6 0 7.149639 -0.644144 -0.01331625 6 0 5.404852 -2.922375 -0.04491326 6 0 7.651449 -1.944027 -0.02625227 1 0 7.811256 0.216910 -0.00145728 6 0 6.791851 -3.066482 -0.04183129 1 0 4.745831 -3.784607 -0.05705130 1 0 8.725928 -2.102268 -0.02448131 1 0 7.221991 -4.063572 -0.05166432 6 0 -4.964452 -1.655198 -0.02439033 1 0 -2.789433 -1.692374 -0.02156234 6 0 -5.793516 -0.496456 -0.01829435 6 0 -5.492470 -2.951241 -0.03303636 6 0 -7.190738 -0.639047 -0.02121337 6 0 -6.882348 -3.068182 -0.03583338 1 0 -4.850496 -3.826457 -0.03746939 6 0 -7.719118 -1.928736 -0.03000840 1 0 -7.835386 0.235025 -0.01668241 1 0 -7.332169 -4.056652 -0.04257842 1 0 -8.796686 -2.065054 -0.03243643 7 0 -3.676705 -1.170740 -0.01941744 7 0 -5.016244 0.648504 -0.00980945 6 0 -3.764118 0.203986 -0.01080346 7 0 4.999905 0.685037 -0.00540847 7 0 3.623201 -1.108604 -0.03065448 1 0 1.032905 0.589981 -0.01217549 6 0 0.040040 -3.015486 0.03729250 8 0 0.998331 -2.189932 -0.075998-----------------------------------------------------------------------9.Structural parameters (which are involved in ESIPT directly) of tautomers and acetatecomplex of Enol in their ground and excited state (optimized excited state geometry).Table S4:10. HOMO -LUMO transitions, compositions, vertical excitation and oscillator strength:Table S5:Enol MediumStateAssignment bE Cal (eV)λCal (nm)fGasS1HOMO→LUMO (94%)HOMO-1→LUMO (4%)2.8078441.570.3070S2HOMO-1→LUMO (78.7%)HOMO→LUMO +1 (16%)3.7513390.580.8186HOMO-1(-6.11 eV) HOMO(-5.837eV) LUMO(-2.616eV)LUMO+1(-2.094eV)ACNS 1HOMO→LUMO (92%)HOMO-1→LUMO (5%)2.9221 424.3 0.719711.Theoretical Calculation for Shorter Emission aTable S6:aThe energies at ground state (distorted or unrelaxed) and excited state of Enol in gas phase and ACN-solvents were considered for shorter emission calculations.S 3HOMO-1→LUMO (14%)HOMO-1→LUMO+1 (37%) HOMO→LUMO+1 (43%)3.423362.230.581HOMO-1(-6.168eV)HOMO(-6.041)LUMO(-2.61eV)LUMO+1(-2.248eV)12. Theoretical Calculation for Longer Emission bTable S7:b The energies at ground state (distorted or unrelaxed) and excited state of Keto in gas phase and ACN-solvents were considered for longer emission calculations.。