Proton solvation: competition between acetone and dimethyl sulfoxide
Abstract
This paper presents results of quantum-chemical study of proton exchange equilibrium between acetone (AC) and dimethyl sulfoxide (DMSO). Basing on the previous study of acid-base equilibria in AC with small additives of DMSO, the most probable composition of the lyonium ion is taken as H(DMSO)2+. The equilibrium geometries and energies of solvents molecules and all possible combinations of proton complexes with one or two solvent molecules were calculated in DFT level of theory using B3LYP functional and 6-31G++(d,p) basis set. The energies of solvated proton complexes were then calculated using PCM method. The energy change corresponding to the equilibrium H(AС)2+ + 2 DMSO ⇄ H(DMSO)2+ + 2 AС is –63.1 kJ mol–1 in the gas phase, which is in qualitative agreement with the standard Gibbs energy data, obtained experimentally in the gas phase by Kebarle’s group, –77.6 kJ mol–1, and with ΔGo298 = –49.3 kJ mol–1 for AC solution with small additions of DMSO, determined by the Guss and Kolthoff method.
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Reichardt C., Welton T. Solvents and Solvent Effects in Organic Chemistry. Wiley-VCH; Weinheim, 2011.
Fawsett W.R. Acidity and basicity scales for polar solvents. J. Phys. Chem., 1993, 97 (37), 9540-9546. https://doi.org/10.1021/j100139a045
Lebed A.V., Mchedlov-Petrossyan N.O., Filatov D.Yu., Goga S.T. Acid-base equilibrium in a mixture of protophobic and protophilic polar non-hydrogen bond donor solvents: Stoichiometry of proton solvation by dimethyl sulfoxide in acetone. Proc. Nat. Acad. Sci. Ukraine. 2008, no. 9, 121-125. http://dspace.nbuv.gov.ua/handle/123456789/5919
Mchedlov-Petrossyan N.O., Filatov D.Yu., Goga S.T., Lebed A.V. Ionic equilibrium in mixtures of protophobic and protophilic polar non-hydrogen bond donor solvents: Acids, salts, and indicators in acetone containing 5 mol % DMSO. J. Phys. Org. Chem., 2010, 23(5), 418-430. https://doi.org/10.1002/poc.1616
Williams J.M., Kreevoy M. Structure and infrared spectrum of the solvated proton in dimethyl sulfoxide. J. Am. Chem. Soc. 1967, 89(21), 5499-5501. https://doi.org/10.1021/ja00997a062
Kampschulte-Scheuing I., Zundel G. Tunnel effect, infrared continuum, and solvate structure in aqueous and anhydrous acid solutions. J. Phys. Chem., 1970, 74(11), 2363-2368. https://doi.org/10.1021/j100705a021
Gaussian 09, Revision A.02, M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone, G. A. Petersson, H. Nakatsuji, X. Li, M. Caricato, A. Marenich, J. Bloino, B. G. Janesko, R. Gomperts, B. Mennucci, H. P. Hratchian, J. V. Ortiz, A. F. Izmaylov, J. L. Sonnenberg, D. Williams-Young, F. Ding, F. Lipparini, F. Egidi, J. Goings, B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V. G. Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, K. Throssell, J. A. Montgomery, Jr., J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, J. M. Millam, M. Klene, C. Adamo, R. Cammi, J. W. Ochterski, R. L. Martin, K. Morokuma, O. Farkas, J. B. Foresman, and D. J. Fox, Gaussian, Inc., Wallingford CT, 2010.
Denisov G.S., Koll A., Lobadyuk V.I., Schreiber V.M., Shurukhina A.V., Spevak V.N. Hydrogen bonding in coordination compounds containing homoconjugated bis-dimethylsulfoxide cation. Ab initio and IR studies. J. Mol. Struct., 2002, 605(2-3), 221-226. https://doi.org/10.1016/S0022-2860(01)00783-9
Lau Y.K., Saluja P.P.S., Kebarle P. The proton in dimethyl sulfoxide and acetone. Results from -phase ion equilibria involving (Me2SO)nH+ and (Me2CO)nH+ . J. Amer. Chem. Soc., 1980, 102(25), 7429-7433. https://doi.org/10.1021/ja00545a004
Guss L.S., Kolthoff I.M. The distribution of protons between water and other solvents. J. Amer. Сhem. Soc., 1940, 62(6), 1494-1496. https://doi.org/10.1021/ja01863a047
Foltin M., Majer P. Determination of dissociation constant of picric acid and calibration of potentiometric cell in acetone. Coll. Czech. Chem. Commun., 1978, 43(1), 95-102. https://doi.org/10.1135/cccc19780095