RutheniumII(p-cymene) complexes bearing ligands of the type 1-[2′-(methoxycarbonyl)phenyl]-3-[4′-X-phenyl]triazenide (X = F, Cl, Br, I): Synthesis, structure and catalytic activity

Abstract

The synthesis and characterization of triazenes of the type 1-[2′-(methoxycarbonyl)phenyl]-3-[4′-X-phenyl]triazene [X=F (1), Cl (2), Br (3), I (4)] as precursors of triazenide ligands for the preparation of their complexes of formula [Ru{1-(2′-methoxycarbonylphenyl)-3-(4′-X-phenyl)triazenide}(Cl)(p-cymene)] [X=F (6), Cl (7), Br (8), I (9), CH3 (10)] are reported. Molecular structures for all four triazenes (1–4), and of complexes 6, 9 and 10 were determined by X-ray diffraction studies. Complexes 6–10 were tested as catalysts in the transfer hydrogenation of acetophenone in the presence and in the absence of base. The best results were obtained in the presence of base with yields in the range of 86–94%, whereas even in the absence of base yields in the range 42–65% were achieved.