Preparation of binuclear complexes using 2-(diphenylphosphino)pyridine as a bridging ligand. Synthesis of some ruthenium complexes and their interaction with palladium complexes

Article abstract of DOI:10.1021/ic00141a020

The reactions between Ru(Ph₂Ppy)₂(CO)₃ and (1,5-cyclooctadiene)PdCl₂ and between Ru(Ph₂PPy)₂(CO)₂Cl₂ and Pd₂-(dibenzylideneacetone)₃ have been examined as routes to binuclear Ru/Pd complexes. The first reaction produces Ru-(Ph₂Ppy)₂(CO)₂Cl₂, Ru(Ph₂Ppy)(CO)₂Cl₂, Pd₂(Ph₂Ppy)₂Cl₂, and two isomers of RuPd(Ph₂Ppy)₂(CO)₂Cl₂, while the second forms predominantly the two binuclear products. Syntheses of Ru₃(CO)₉(Ph₂Ppy)₃, Ru(Ph₂Ppy)₂(CO)₃, and Ru-(Ph₂Ppy)₂(CO)₂Cl₂ from Ru₃(CO)₁₂ are reported as are the preparations of Pd(Ph₂Ppy)₂Cl₂ and Pd₂(Ph₂Ppy)₂Cl₂. All new compounds have been characterized by infrared spectroscopy and ³¹P{¹H} NMR spectroscopy. The two isomers of RuPd(Ph₂Ppy)₂(CO)₂Cl₂ interconvert on heating in solution. The structure of one isomer has been determined unambiguously by X-ray crystallography. RuPd(Ph₂Ppy)₂(CO)₂Cl₂ crystallizes in the space group P2₁/c with cell dimensions (determined at 140 K) of a = 10.493 (2) ?, b = 17.685 (4) ?, c = 21.470 (5) ?, β = 92.07 (2)°, Z = 4, and V = 3982 (1) ?³. The structure was refined by blocked cascade least-squares to a conventional R value of 0.043 by using 4605 significant reflections. The compound possesses a Pd-Ru bond with a distance of 2.660 (1) ?. The palladium atom is four-coordinate with a Ru, Cl, P, N donor set, while the ruthenium atom is six-coordinate with a Pd, Cl, P, N, C₂ donor set.