Synthesis of the donor–acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (d...

The synthesis of the donor–acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd) from the Knoevenagel condensation of 4-(dimethylamino)benzaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) is reported. This new ligand reacts with PtCl2(cod) to afford the platinum(II) complex PtCl2(dbpcd) in high yield. The dbpcd ligand and PtCl2(dbpcd) have been isolated and characterized by IR and NMR spectroscopies, cyclic voltammetry, MO calculations at the extended Hückel level, and X-ray diffraction analysis in the case of PtCl2(dbpcd).