Syntheses, Structures, and Catalytic Properties of Ruthenium(II) Nitrosyl Complexes with Pyridine-Functionalized N-Heterocyclic Carbenes

Ruthenium(II) nitrosyl complexes with pyridine-functionalized N-heterocyclic carbenes [( L )Ru(NO)Cl 3 ] [L = 3- tert -butyl-1-(2-pyridyl)imidazol-2-ylidene, 2a; 3- n -butyl-1-(2-pyridyl)imidazol-2-ylidene, 2b; 3- tert -butyl-1-picolylimidazol-2-ylidene, 2c; 3- n -butyl-1-picolylimidazol-2-ylidene, 2d; and 3-benzyl-1-picolylimidazol-2-ylidene, 2e ] have been prepared by transmetalation from the corresponding silver carbene complexes. Compounds 2a − c have been characterized by single-crystal X-ray crystallography. Compounds 2a − e show catalytic activities in transfer hydrogenation of ketones.