Abstract
The transfer of protons from dithiophosphoric acids R2PSSH to substituted pyridines and proton exchange between the SH groups of the same acids and NH of protonated pyridines in chloroform solution were studied. The results obtained are compared with the analogous data for monothiocarboxylic acids RCOSH. The mechanism of SH-NH exchange was established; its slow step, just as for RCOSH, is transfer of a proton in the ion pairs
. In the transition from RCOSH to R2PSSH, an increase in the thermal effect of the deprotonation of the acids by amines and the activation energy E of SH-NH proton exchange is observed, which is due to the greater stability of the R2PSS− anions in comparison with RCOS− on account of the greater delocalization of charge on the two sulfur atoms. With increasing excess of acid (above two-fold), the values of E are increased, since the excess acid molecules more effectively solvate the ion pairs than the original molecular complexes.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature cited
V. K. Pogorelyi and V. V. Turov, “NMR investigation of rapid proton exchange with the participation of thiocarboxylic acids,” Teor, Eksp. Khim.,16, No. 5, 643–648 (1980).
V. K. Pogorelyi and V. V. Turov, “PMR investigation of the kinetics of proton exchange of dithiophosphoric acids with acetic and thioacetic acids,” Teor. Eksp. Khim.,17, No. 5, 628–633 (1981).
V. K. Pogorelyi and V. V. Turov, “Investigation of rapid proton exchange between the SH groups of thiocarboxylic acids and the NH of triethylammonium,” Teor. Eksp. Khim.,19, No. 6, 698–703 (1983).
V. K. Pogorelyi and V. V. Turov, “Investigation of the equilibrium and kinetics of proton transfer from thiocarboxylic acids toγ-collidine,” Teor. Eksp. Khim.,21, No. 2, 187–194 (1985).
V. N. Barvinchenko and V. K. Pogorelyi, “Investigation of the hydrogen bonds of thioacetic and chlorothioacetic acids with various electron donor,” Teor. Eksp. Khim.,17, No. 6, 839–844 (1981).
C. G. Swain and M. M. Labes, “The mechanism of exchange of hydrogen between ammonium and hydroxyl groups,” J. Am. Chem. Soc.,79, No. 5, 1084–1088 (1957).
Author information
Authors and Affiliations
Additional information
Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 6, pp. 676–681, November–December, 1985.
Rights and permissions
About this article
Cite this article
Pogorelyi, V.K., Turov, V.V. Investigation of the kinetics and equilibrium of the transfer of protons from dithiophosphoric acids to amines. Theor Exp Chem 21, 645–649 (1985). https://doi.org/10.1007/BF00945140
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00945140