Noninnocent behavior of bidentate amidophosphido [NP]2- ligands upon coordination to copper

Abstract

The synthesis and preliminary coordination chemistry of two new redox-active bidentate ligands containing amido and phosphido donors are described. Treatment of the [RNP]2- (R = Ph, 2,4,6-trimethylphenyl) ligands with CuCl2 and PMe3 results in a dimeric copper(I) P-P coupled product via ligand oxidation. The intermediate of this reaction is proposed to involve a ligand radical generated via oxidation of the [RNP]2- ligand by copper(II), and the existence of such an intermediate is probed using computational methods. Significant radical character on the phosphorus atoms of the alleged [ RNP]•-/copper(I) intermediate leads to P-P radical coupling. © 2013 American Chemical Society.