Synthesis, Coordination Chemistry, and Catalysis of the First 1,2-Bis(diphenylphosphino)-1,2-diphenylhydrazine, Ph₂PN(Ph)N(Ph)PPh₂

The reaction of chlorodiphenylphosphine with dilithiohydrazobenzene gave 1,2-bis(diphenylphosphino)-1,2-diphenylhydrazine, [PPh2N(Ph)N(Ph)PPh2] (1). Treatment of 1 with NiCl2(DME), PdCl2(PhCN)2, and PtCl2(COD) resulted in the formation of complexes of the type cis-[MCl2{Ph2PN(Ph)N(Ph)PPh2}] (M = Ni (3), Pd (4), Pt (5)). The molecular structures of the starting ligand 1 and the complexes 3, 4, and 5 have been determined by X-ray diffraction. The ligand 1 and its Ni(II) complex 3 were evaluated for their catalytic activity in the oligo-/polymerization of ethylene using methylaluminoxane (MAO) and triethylaluminium (TEA) as cocatalyst.