KINETICS OF THE SOLVOLYSIS OF A CATIONIC AND OF AN ANIONIC CHLOROCOBALT(III) COMPLEX IN WATER-GLUCOSE MIXTURES - ANOMALOUS EFFECTS ON THE ENTHALPY AND ENTROPY OF ACTIVATION
Kh. Halawani et Cf. Wells, KINETICS OF THE SOLVOLYSIS OF A CATIONIC AND OF AN ANIONIC CHLOROCOBALT(III) COMPLEX IN WATER-GLUCOSE MIXTURES - ANOMALOUS EFFECTS ON THE ENTHALPY AND ENTROPY OF ACTIVATION, Journal of the Chemical Society. Faraday transactions, 89(19), 1993, pp. 3565-3569
Citations number
47
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The kinetics of the solvolysis of the ions [Co(4-Butpy)4Cl2]+ and [Co(
CN)5Cl]3- have been investigated in a range of water-rich mixtures of
water with hydrophilic glucose over a range of temperatures. The varia
tions of the enthalpies and entropies of activation with solvent compo
sition show extrema such as found in mixtures of water with hydrophobi
c co-solvents even though the extrema found in the physical properties
of the latter mixtures are not present in those of the mixtures of wa
ter with glucose. The application of a Gibbs energy cycle to the proce
ss of the initial state going to the final state is compared for both
complexes with the results from the same cycle applied using both hydr
ophilic and hydrophobic solvents mixed with water. Although there are
differences between the behaviour of the two complexes with varying co
-solvent, in all cases the emergent solvated cobalt ion in the transit
ion state is more stable in the mixtures than the cobalt ion in the in
itial state.