Supporting Information Tetrathiafulvalene Diindolylquinoxaline: A Dual Signaling Anion Receptor with Phosphate Selectivity Christopher Bejger, Jung Su Park, Eric S. Silver, and Jonathan L. Sessler* 1. Synthetic Experimental a. 1 H NMR Spectroscopic Data b. 13 C NMR Spectroscopic Data c. Mass Spectrometry 2. UV-Binding Isotherms a. UV-Vis Spectral Titrations with TBAH 2 PO 4 b. Binding Isotherms c. Job Plot 3. CV Studies 4. 1 H NMR Spectroscopic Analyses 5. X-ray Crystallography 6. References for Supporting Information S1
General Procedures Proton and 13 C NMR spectra were measured at 25 C using a 400 MHz Varian Unity Innova instrument. UV-vis spectra were recorded on a BECKMAN DU 640B spectrophotometer. High resolution ESI mass spectra were obtained on a Varian Ion Spec (9.4 T FTMS) ESI Source mass spectrometer. Fluorescence spectra were recorded on Horiba Jobin Yvon Nanolog. Electrochemistry was done on a CV-50W Voltammetric Analyzer. 1. Synthetic Experimental TTF-Diamine (5,6-diamino-2-(4,5-bis(propylthio)-1,3-dithio-2-ylidene)benzo[d]-1,3-dithiole) 1 (161 mg, 0.23 mmol) and 2,3-diindol-3 yl 2 (90 mg, 0.37 mmol) were dissolved in 50 ml EtOH and 50 ml acetic acid and heated at reflux overnight. The resulting solution was concentrated in vacuo and subject to column chromatography (silica gel, CH 2 Cl 2 /EtOAc (7/1, v/v) eluent) to give 1 as a purple solid (47 mg, 22%). 1 H NMR (400 MHz; dichloromethane-d 2 ) δ 8.42 (s, NH, 2H), 8.02 (d, J = 8.5 Hz, 2H), 7.92 (s, Ar-H, 2H), 7.43 (d, J = 8.13 Hz, 2H), 7.36 (s, 2H), 7.23 (t, J = 7.02, 6.96 Hz, 2H), 7.12 (t, J = 8.11, 6.99 Hz, 2H), 2.84 (t, J = 7.09, 7.32, -S-propyl, 4H), 2.84 (m, -S-propyl, 4H), 1.03(t, J = 7.31, 7.34 Hz, -S-propyl, 6H) ppm; 13 C NMR (125 MHz; DMSOd 6 ) δ 149.7, 138.4, 137.7, 136.2, 128.1, 126.9, 125.9, 121.9, 121.3, 120.4, 120.1, 113.9, 111.9, 110.9, 110.7, 37.4, 22.7, 12.8 ppm. MS m/z: 685.07 [M + ]. Quantum yield (φ F ) in dichloromethane = 0.002. S2
a. 1 H NMR spectroscopic data for compound 1 S3
b. 13 C NMR spectroscopic data for compound 1 S4
Supplementary Material (ESI) for Chemical Communications S5
S6
2. UV spectroscopic binding isotherms a. Titrations Stock solutions of the host molecule being studied were made up in dichloromethane with the final concentration being 5 x 10-5 M. Stock solutions of the guest were prepared by dissolving 10-300 equivalents of the requisite tetrabutylammonium salts of the selected anions in 5 ml of a stock solution of the host. The molar extinction coefficient for TTFDIQ = 17,090 M -1 cm -1. S7
b. Binding isotherms and calculations of equilibrium constants, K a Equilibrium constants were calculated using the standard 1:1 binding equation for optical titrations originally taken from Connors, 3 where [L] = [anion](cf. eq. 1) and fit using Origin version 7.5. y = B K a x / (1 + K a x) (1) x = [anion], v = ΔA, B = Δε x b., K a = equilibrium constant c. Job Plot A stock solution of the host was prepared as described for the K a determination experiments. The guest stock solution was prepared by dissolving 1-2 equivalents of the TBA salts of the anions in question in the same solvent (dichloromethane) as the one used for the host stock solution. 1-TBAH 2 PO 4 1-TBAOBz S8
1-TBACl 1- TBAHSO 4 1-TBAF 3. CV Studies Cyclic voltammograms of receptor 1 were recorded in CH 2 Cl 2 (2.5 x 10-4 M) using TBAPF 6 (0.3 M) as the supporting electrolyte at a scan rate of 100 mv/s at 298 K. The receptor 1 was titrated by adding increasing amounts of the TBA salt of the anion of study in solution (0.4 S9
equiv.; 0.8 equiv.; 1.2 equiv.; 1.6 equiv.; 2 equiv.) that also contained receptor 1 and TBAPF 6 to counter dilution effects. The potentials were referred to Ag/AgCl. S10
4. 1 H NMR spectroscopic studies carried out in DMSO-d 6 Partial 1 H NMR spectra (400 MHz) recorded in DMSO-d 6: (a) free receptor 1; (b) receptor 1 + 2 equiv. BzO - ; (c) receptor 1 + 2 equiv. Cl - ; (d) receptor 1 + 2 equiv. F - ; (e) receptor 1 + 1.5 equiv. H 2PO 4 - ; (f) receptor 1 + 1.5 equiv HSO 4 -. All anions used in the form of their TBA salts. Note the disappearance of the N-H signal and the broadening of the resonances associated with the aromatic protons that is observed upon the addition of fluoride anion. S11
1 H NMR spectroscopic studies carried out in dichloromethane-d 2 4 Partial 1 H NMR spectra (400 MHz) recorded in dichloromethane-d 2: (a) free receptor 1; (b) receptor 1 + 1.5 equiv. HSO 4 - ; (c) receptor 1 + 1.5 equiv. Cl - ; (d) receptor 1 + 1.5 equiv. BzO - ; (e) receptor 1 + 1.5 equiv. H 2PO 4 - ; (f) receptor 1 + 1.5 equiv. F -. All anions were studied as their TBA salts.! designates the N-H signal of the DIQ moiety. S12
5. X-ray Crystallography for 1 TBA H 2 PO 4 Single crystals were grown as orange laths from equimolar mixtures of 1 and TBA H 2 PO 4 in acetone, into which diethylether was slowly diffused over the course of one week at ambient temperature. X-ray crystallographic data was collected at 50 C on a Rigaku SCX-Mini diffractometer using a monochromatized MoKα source (λ = 0.71070 Å) equipped with a Mercury CCD area detector. The frame data was integrated and corrected for absorption effects using the Rigaku/MSC CrystalClear program package. 4 The structures were solved by direct methods and refined by fullmatrix least-squares on F 2 with anisotropic displacement parameters for the non-h atoms using SHELXL- 97. 5 The function, w( Fo 2 - Fc 2 ) 2, was minimized, where w = 1/[((Fo)) 2 + (X*P) 2 + (Y*P)] and P = ( Fo 2 + 2 Fc 2 )/3 and the parameters, X and Y, are suggested during the refinement process. The hydrogen atoms were calculated in ideal positions with isotropic displacement parameters set to 1.2xUeq of the attached atom (1.5xUeq for methyl hydrogen atoms). Neutral atom scattering factors and values used to calculate the linear absorption coefficient are from the International Tables for X-ray Crystallography (1992). 6 The unit cell contains severely disordered diethylehter molecules which have been treated as a diffuse contribution to the overall scattering without specific atom position by Squeeze/Platon. All the calculations were carried out with the SHELXTL program. 7 The details of the crystallographic data for 1 are summarized in Table S1. Further details of the structure can be obtained from the Cambridge Crystallographic Data Centre by quoting CCDC 781609. Table 1. Crystal data and structure refinement for 1 TBA H 2 PO 4. Empirical formula C208 H284 N20 O19 P4 S24 Formula weight 4262.11 Temperature Wavelength 223(2) K 0.71075 A Crystal system, space group Triclinic, P-1 Unit cell dimensions Volume a = 15.186(3) A alpha = 92.706(5) deg. b = 16.853(3) A beta = 90.213(5) deg. c = 25.923(5) A gamma = 91.252(5) deg. 6625(2) A^3 Z, Calculated density 1, 1.068 Mg/m^3 Absorption coefficient 0.271 mm^-1 S13
F(000) 2268 Crystal size Theta range for data collection Limiting indices 0.20 x 0.14 x 0.11 mm 3.00 to 25.00 deg. -18<=h<=18, -20<=k<=20, -30<=l<=30 Reflections collected / unique 57121 / 23245 [R(int) = 0.1273] Completeness to theta = 25.00 99.7 % Absorption correction Semi-empirical from equivalents Max. and min. transmission 0.9708 and 0.9477 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 23245 / 123 / 1299 Goodness-of-fit on F^2 1.076 Final R indices [I>2sigma(I)] R1 = 0.0851, wr2 = 0.1798 R indices (all data) R1 = 0.1805, wr2 = 0.2045 Largest diff. peak and hole 0.501 and -0.347 e.a^-3 6. References for Supporting Information 1. C. Jia, S. X. Liu, C. Tanner, C. Leiggener, A. Neels, L. Sanguinet, E. Levillain, S. Leutwyler, A. Hauser, S. Decurtins, Chem. Eur. J., 2007, 13, 3804. 2. J. Bergman, T. Janoik, A. L. Johnson, Synthesis, 1999, 4, 580. 3. K. A. Conners, Binding Constants; John Wiley & Sons: New York, 1987, pages 148 and 24. 4. CrystalClear 1.40, Rigaku Americas Corporation, The Woodlands, TX, 2008. 5. G. M. Sheldrick, SHELXL97, Program for the Refinement of Crystal Structure; University of Gottingen, Germany, 1994,. 6. A. J. C. Wilson, International Tables for X-ray Crystallography Vol. C; Kluwer Academic Press: Boston, 1992, Tables 4.2.6.8 and 6.1.1.4 7. G. M. Sheldrick, SHELXTL/PC (Version 5.03). Siemens Analytical X-ray Instruments, Inc., Madison, Wisconsin, USA, 1994. S14