Halogenation of A-frame µ-carbido complexes: synthesis of µ₂-halocarbynes

Abstract

The reaction of [Rh2(μ-C)Cl2(PPh3)4] with bis(diphenylphosphino)methane (dppm) affords the A-frame μ-carbido complex [Rh2(μ-C)Cl2(μ-dppm)2], halide metathesis of which provides [Rh2(μ-C)Br2(μ-dppm)2]. The reactions of the former with PhICl2 or the latter with [pyH][Br3] provide rare examples of μ2-halocarbyne ligands in the complexes [Rh2(μ-CX)(μ-X)X4(μ-dppm)2] (X = Cl, Br).

Graphical abstract: Halogenation of A-frame μ-carbido complexes: synthesis of μ2-halocarbynes Linear bimetallic μ-carbido complexes may be described by one of three distinct bonding modes (Chart 1) depending on the effective atomic number requirements of the metal termini. The simplest and oldest1 involve identical metal termini and are best described as dimetallacumulenic in nature (Class A, Chart 1) with two formal M[double bond, length as m-dash]C double bonds.