Preparation of some dinuclear rhodium complexes with the orthometallated ligand [2,6-(PPh2CH2)2C6H3]− and their catalytic activity for polymerization of phenylacetylene

Reaction of 1,3-(PPh2CH2)2C6H4 (PCHP) with [RhCl(COD)]2 in isopropanol produced a mixture of dinuclear complexes [RhCl(COD)]2(μ2-PCHP), RhH(PCP)(μ-Cl)2Rh(COD), and [RhHCl(PCP)]2(μ2-PCHP). Reaction of RhH(PCP)(μ-Cl)2Rh(COD) with CCl4 produced RhCl(PCP)(μ-Cl)2Rh(COD). The solid-state structure of the latter complex has been characterized by X-ray diffraction. With the exception of [RhHCl(PCP)]2(μ2-PCHP), all the dinuclear complexes in THF are catalytically active for the polymerization of phenylacetylene.