Electron-transfer reactions of cobaloximes. Part II. The transition from outer- to inner-sphere mechanisms with vanadium(II): a non-linear free-energy relation
Abstract
The reduction of a series of cationic cobaloximes of the form [Co(Hdmg)2L2]+ by V2+(aq) has been investigated [Hdmg = dimethylglyoximato(1–); L = EtNH2, PhNH2, py, or 3,5-Me2py]. Rate constants and activation parameters at 25 °C are reported. A plot of ΔG‡ for these reactions against E½ for the polarographic reduction is used to illustrate the progression from inner- to outer-sphere mechanism as the base strength of the axial ligands if lowered.