Coordination-sphere dynamics of bisphosphine o-semiquinone complexes of copper(I)

Abstract

Depending on steric effects of phosphine and o-semiquinone (SQ) ligands bonded to the copper atom, (R3P)2CuSQ complexes have either pseudotetrahedral geometry with equivalent phosphine ligands or trigonal-pyramidal with one equatorial and one axial phosphine ligand. In an ESR study of the exchange dynamics of the phosphine ligands in trigonal-pyramidal complexes, the kinetic parameters of the exchange were determined. A model was proposed which explains distortions in the geometry of the complexes by nonvalence interatomic interactions on the “periphery” of the phosphine and SQ ligands.