Study of the Base-Catalyzed Nitrito–Nitro Isomerization Reaction ([(NH3)5Co-ONO]2+ → [(NH3)5Co-NO2]2+) in Mixed Solvents

6 pags. ; 4 figs. ; 2 tabs.5Co-NO2]2+ form is studied in various isodielectric water–cosolvent mixtures (methanol, ethanol, tert-butyl alcohol, and 2-propanol) at 298 K. In all cases, except for methanol–water mixtures, the rate constants increase with the proportion of cosolvent. Medium effects have been rationalized by using a multiparameter regression of solvent parameters which rationalizes the results obtained, including water–methanol mixtures. The experimental data, k2, in fact, are well correlated through the following equation: ln k2 = ln(k2)0 + aA + bB + cGexc where A, B, and Gexc are the acidity parameter, the basicity parameter, and the excess Gibbs free energy of the mixture, respectively. C 2004 Wiley Periodicals, IncD.G.I.C.Y.T.: Grant Number: BQU-2002-01063 Consejería de Educación y Ciencia de la Junta de Andalucía, University of SevillePeer reviewe