The reactivity of 1,1-dichloro-2,2-di-tert-butyldiphosphane towards lithiated metal carbonyls: a new entry to phosphanylphosphinidene dimers

Abstract

Reactions of [Cp*(OC)₃M]Li (Cp* = C₅Me₅, M = Mo, W) towards t-Bu₂P–PCl₂ lead to the formation of phosphanylphosphinidene dimers [Cp*(OC)₃M(η²-t-Bu₂P–P)]₂ in fairly good yields. The formation of a tetraphosphorus ligand proceeds via reductive dimerization of t-Bu₂P–P units. NMR, X-ray investigations and DFT calculations show that the resulting tetraphosphorus ligand has a structure of dication t-Bu₂P⁺P–PP⁺t-Bu₂.