REACTIONS OF SIGMA-BONDED ORGAN CHROMIUM(Ⅲ) COMPLEXES

摘要

Three projects were carried out, each dealing with the kinetics and mechanism of reactions of sigma-bonded organo-chromium（III) complexes of the form (H20)5CrE2+. Part I describes the kinetics of the reaction of dichloromethyl-chromium (III) ion with chrorolum(II) ion in aqueous acid according tonCrCHCl22+ + 2 Cr2+ + H+ → CrCl2+ + CrCH2Cl2+ + Cr3+nThe rate law for this reaction is -d[CrCKCl22+]/dt = kCr[CrCHCl22+3[Cr2 + ] (kCr ＝ O.Ol4 M-1s-1 at 25°), and radio¬tracer experiments, in which one reactant was tagged with Cr-51, showed that the radioisotope is distributed Into all chromium products. These results are consistent with a mechanism in which initial halogen atom abstraction by Cr2 produces CrCl2+ and a radical intermediate that reacts further with Cr2+ and H+ via a dinuclear intermediate to form the other products.