Bicyclic dinuclear tris-(ditopic diphosphane) complexes of zerovalent group 10 metals

Abstract

Selective formation of bimetallic group 10 complexes using the C_s symmetric, bicyclic diphosphane P₂C₁₂H₂₀ is reported herein. With its eclipsed lone pairs disposed at a relative angle of ca. 45°, the diphosphane framework is ideally suited to form multiple bridges between two metal centers. The complexes contain {M₂P₆} cages with three diphosphane bridges and a pair of trans-axial ligands such as EPh₃ (E = P, As, Sb) or η¹-P₂C₁₂H₂₀. X-Ray crystallography experiments revealed that the cages have a pseudo-D_3h symmetry, with metal–metal distances in the 3.9–4.1 Å range. The complexes were isolated in 48–91% yield as crystalline, bright yellow or orange powders. Substitution of the axial ligands with the {M₂P₆} cages remaining intact was also observed.