Preparation, characterization, and catalytic properties of ruthenium nitrosyl complexes with polypyrazolylmethane ligands

Ruthenium(II) nitrosyl complexes with polypyrazolylmethanes, [(Bpm)Ru(NO)Cl3] [Bpm = bis(1-pyrazolyl)methane, 1], [(Bpm∗)Ru(NO)Cl3] [Bpm∗ = bis(3,5-dimethyl-1-pyrazolyl)methane, 2], [(Tpm)Ru(NO)Cl2][PF6] [Tpm = tris(1-pyrazolyl)methane, 3], and [(Tpm∗)Ru(NO)Cl2][PF6] [Tpm∗ = tris(3,5-dimethyl-1-pyrazolyl)methane, 4], have been synthesized and characterized. The solid-state structures of [(Bpm∗)Ru(NO)Cl3] (2) and [(Tpm∗)Ru(NO)Cl2][PF6] (4) were determined by single-crystal X-ray crystallographic analyses. These complexes have been tested as catalysts in the transfer hydrogenation of several ketones under mild conditions.