Kinetics of complex formation reactions of chloromethyl(aquo)cobaloxime complex with cyanide and imidazoles

Abstract

Formation constants have been determined for the reaction of ClCH₂Co(DH)₂OH₂ with CN^- and different imidazole based nucleophiles as a function of<i> p</i>H. The kinetics of this reaction has been studied as a function of entering ligand concentration at a fixed <i>p</i>H and as a function of <i>p</i>H at a fixed concentration of the entering ligand. Dissociation reaction has also been studied as a function of <i>p</i>H. Bonding and kinetic data have been interpreted based on the basicity, bulkiness (steric crowd) of the entering ligand and HSAB principle. The soft ligand CN^- binds very strongly. To compare the rate constants of the entering ligands,<i> p</i>H independent second order rate constants have been calculated.