Kinetics of formation, dissociation and equilibrium constants of pentacyanoaquoruthenate(II) with heterocycles
Y Baran
article (Uluslararası, Hakemli) | Yazar(lar): Y Baran | Yıl: 2000 | Dergi/Kurum: TRANSITION METAL CHEMISTRY | İndeks: WOS.SCI — Özet: The kinetics of formation and dissociation reactions of [Ru(CN)(5)L](3-) with a series of heterocyclic ligands were studied in aqueous media. In this presence of an excess of heterocycle
The kinetics of formation and dissociation reactions of [Ru(CN)(5)L](3-) with a series of heterocyclic ligands were studied in aqueous media. In this presence of an excess of heterocycle, the observed second order rate constants were calculated from the k(obs) versus [ligand] plot at mu = 0.100 m NaClO4. Activation parameters for the formation reactions (Delta H double dagger = 28 +/- 7 kJ mol(-1) and Delta S double dagger = 140 +/- 35 J K-1 mol(-1)) are comparable for all systems, indicating a common mechanism. The kinetics of exchange of coordinated heterocycles for 1,3,5-triazine yielded a rate saturation typical of a limiting dissociative mechanism. Activation parameters of the limiting first order specific rate of dissociation reactions were Delta H double dagger = 85 +/- 7 kJ mol(-1) and Delta S double dagger =18 +/- 4 J K-1 mol(-1). Equilibrium constants were calculated from the second order rates of formation and pseudo-first order rates of dissociation reaction.