Iminophosphorane Complexes of Palladium(II)

Iminophosphorane complexes of palladium [(C6H5)3P=N–C6H4–X-p]PdCl2(CH3CN) (X=NO2, 1A; COO-C2H5, 2A; Cl, 3A; H, 4A; CH3, 5A) have been prepared by ligand-substitution reaction between (C6H5CN)2PdCl2 and the parent iminophosphoranes, followed by recrystallization from acetonitrile-ethyl acetate. Other iminophosphoranes (X=OCH3, and (C6H5)2(CH3)P=N–Si(CH3)3), however, gave only dimeric complexes with the [(Iminophosphorane)PdCl2]2 composition. Complexes 1A–5A and {[(C6H5)3P=N–C6H4–X-p]PdCl2}2 (X=NO2, 1B; COOC2H5, 2B; Cl, 3B; H, 4B; CH3, 5B) are also discussed. The ligand-exchange reaction of 2B and 5B with α,α′-bipyridine, (C6H5)3P, and (CH3O)3P took place, liberating the parent iminophosphorane.