Ligand substitution at five-co-ordinate centres. Reactions of tributylphosphine adducts of bis(O-dialkyl dithiophosphato)nickel(II) complexes

Abstract

Tri-n-butylphosphine, PBu₃, reacts with bis(O-dialkyl dithiophosphato)nickel(II) complexes, [Ni{S₂P(OR)₂}₂], in benzene to produce five-co-ordinate adducts. Physical properties of the adducts (R = Et, PhCH₂CH₂, and C₆H₁₁) and the kinetics of their reaction with various bidentate nucleophiles are reported. The mechanism is strictly dissociative with the PBu₃ group being required to dissociate before the reaction can proceed.