Kinetics studies of the electrophilic cleavage of the Co-C bond in a series of six CH3Co(chelate) H2O complexes by Hg2+ were carried out. The kinetic data support an electrophilic (Se2) mechanism, in that changes in electron density at the cobalt center which accompany the variation in chelate structure are transmitted to the transition state for the heterolytic cleavage of the C0-CH3 bond. The values of k/M™1 sec™1 at 25.0°and µ LO Min aqueous solution are as folows: saloph, (3.3 ± 0.3) X 104; salen, (2.6 ± 0.4) X 104; Measalen, (2.1 ± 0.1) X 104; (dmgH)2, 65 ± 2; dpnH, 1.77 ± 0.03; tim (at µ 1.60 M), (4.5 ± 0.5) X 10™4. For the first four members, the reaction rate is lowered by [H+], attributed to the protonation of the cobalt complex to an unreactive form; the equilibrium constants for these interactions were also evaluated.

Die kinetischen Daten der elektrophilen Spaltung der Co‐C o‐Bindung in den Komplexen (I) und (II) durch Hg(II) zeigen einen elektrophilen SE2‐Mechanismus.