Isolation and Characterization of New Mono- and Polynuclear Complexes Formed in the Thermal Reaction of Ru₃(CO)₁₂ with 1-(4-Tolyl)-3-phenylaminoprop-2-en-1-one

Abstract

Thermal reaction of Ru 3 (CO) 12 with 1-(4-tolyl)-3-phenylaminoprop-2-en-1-one (1) proceeds in heptane with the formation of a number of new chelate mononuclear complexes, cis-Ru(CO) 2 [OdC-(Tol)CHdCHNPh] 2 (2), cis-Ru(CO) 2 [OdC(Tol)CHdCNHPh][OdC(Tol)CHdCH-NPh] (3), and cis-Ru(CO) 2 [OdC(Tol)CHdCNHPh][OdC(Tol)CHdCHNPh] (4), isolated as the main products, along with minor amounts of the polynuclear clusters Ru 5 (CO) 14 (μ 2 -H) 2 (μ 4 -η 1 :η 1 :η 2 :η 2 -CCHC(Tol)dO) (5), Ru 4 (CO) 11 (μ 2 -H) 2 (μ 4 -η 2 :η 2 :η 1 :η 2 -NPhCCHC(Tol)dO) (6), and Ru 4 (CO) 12 -(μ 4 -η 1 :η 1 :η 1 :η 1 -NPhCHCC(Tol)dO) (7). Complexes of both series were characterized by a combination of spectroscopic IR and multinuclear NMR data and by single-crystal X-ray diffraction study, which revealed the existence of different types of metal-to-ligand bonding in these species. Chelated six-membered azaoxaruthenacycles are formed in 2-4 via N-H activation, while unexpected fivemembered oxaruthenacycles are formed in 3-6 due to C β -H activation. Among the products of the reaction, the butterfly cluster 7, with open-chain coordination of the ligand formed as a result of N-H and C R -H bond activation, is also isolated. Complex 5 proved to be the only reaction product in which the deamination of amino vinyl ketone 1 is observed. Possible pathways for the formation of the complexes obtained are discussed.