Di- and tetranulcear RuII complexes of phenylene-1,4-diaminotetra(phosphonite), p-C6H4[N{P(OC6H4OMe-o)2}2]2 and their catalytic investigation towards transfer hydrogenation reactions

The stoichiometric reaction of phenylene-1,4-diaminotetra(phosphonite), p-C6H4[N{P(OC6H4OMe-o)2}2]2 (P2NФNP2) (1) with [RuCl2(p-cymene)]2 in acetonitrile produces cis,cis-[{RuCl2(CH3CN)2}2(P2NФNP2)] (2), whereas the similar reaction of 1 with [RuCl2(p-cymene)]2 in THF medium affords a tri-chloro-bridged tetrametallic complex, [{(η6-p-cymene)Ru2(μ2-Cl)3Cl}2(P2NФNP2)] (3) irrespective of the stoichiometry and reaction conditions. The formation and structure of complexes 2 and 3 are assigned through various spectroscopic and micro analysis data. The molecular structure of 2 is confirmed by single crystal X-ray diffraction study. The catalytic activities of complexes 2 and 3 have been investigated in transfer hydrogenation reactions.