ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Kinetics of anation of pentaammineaquachromium(III) and pentaammineaquacobalt(III) ions with thiocyanate in aqueous organic mixtures

V. Holba and M. Talapka

Department of Physical Chemistry, Faculty of Natural Sciences, Komenský University, 816 34 Bratislava

Abstract:  The kinetics of anation of pentaammine-aquachromium(III) and pentaammine-aquacobalt(III) ions with thiocyanate ion were investigated in aqueous mixtures of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, tert-butyl alcohol, and dioxan. The dependence of the logarithm of the rate constants on the reciprocal value of the relative permittivity is only for the reaction of Cr(III) complex in all investigated solvents linear. The interpreta- tion of the experimental data, based on the electrostatic theory in the case of the reaction of Co(III) complex is possible only when methyl alcohol and ethyl alcohol are used as co-solvents. The connection of the observed phenomena with mechanism of the reactions under study is discussed.

Full paper in Portable Document Format: 354a447.pdf

Chemical Papers 35 (4) 447–458 (1981)