Substituted metal carbonylsXVIII. rhenium 1,1′-bis(diphenylphosphino)ferrocene (DPPF) complexes derived from [Re2(CO)9]. Crystal structures of two isomorphous pentametallic [M2(CO)9]2(μ-dppf) (M Mn, Re) and trimetallic Re2(CO)9(dppfO) complexes

Abstract

Amine oxide-assisted decarbonylation of Re2(CO)10 in the presence of 1,1′-bis(diphenylphosphino)ferrocene (dppf) produces, under different conditions, [Re2(CO)9]2 (μ-dppf) (1), Re2(CO)9(1-dppf) (5) and its oxidation product Re2(CO)9(1-dppfO) (7). 1 undergoes an oxidative bridge-scission with Me3NO to give 7. X-ray crystallographic analysis of 1 and [Mn2(CO)9]2(μ-dppf) (2), included for comparison, revealed that the two molecules are isomorphous, each taking the form of an open and "linear" tetranuclear complex supported alternately by M M bonds and a "half eclipsed" dppf bridge. Complex 7, which is trimetallic, consists of dppf (mono)oxide coordinated to [Re2(CO)9] through the phosphine site. X-ray Photoelectron Spectra revealed the existence of the chemically inequivalent Re and P sites within the same molecule. The chemically distinct Re centres in 1, 5, 7 and Re2(CO)9(CH3CN) are differentiable by their Re(4f7/2) and Re(4f5/2) binding energies. © 1991.