@article{lee_ke_ramirez_gunnoe_cundari_boyle_petersen_2009, title={Six-, Five-, and Four-Coordinate Ruthenium(II) Hydride Complexes Supported by N-Heterocyclic Carbene Ligands: Synthesis, Characterization, Fundamental Reactivity, and Catalytic Hydrogenation of Olefins, Aldehydes, and Ketones}, volume={28}, ISSN={["1520-6041"]}, DOI={10.1021/om801111c}, abstractNote={The Ru(II) hydride complex (IMes)2Ru(Cl)(H)(CO) (1) {IMes = 1,3-bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene} was synthesized from [Ru(CO)2Cl2]n and free IMes. Complex 1 rapidly reacts with CO to produce the cis-dicarbonyl Ru(II) complex (IMes)2Ru(Cl)(H)(CO)2 (2). The reaction of 1 with NaBAr′4 {Ar′ = 3,5-(CF3)C6H3} produces the four-coordinate Ru(II) cationic complex [(IMes)2Ru(H)(CO)][BAr′4] (4), which can be trapped by two equivalents of tert-butylisonitrile to produce [(IMes)2Ru(H)(CO)(CNtBu)2][BAr′4] (5). Experimental and computational studies suggest that complex 4 is a diamagnetic system that adopts a sawhorse structure. The hydride ligand of complex 2 is readily displaced as dihydrogen upon reaction with HCl to produce (IMes)2Ru(Cl)2(CO)2 (3). Both complex 1 and 4 were found to react with D2 (30 psi) at room temperature to produce the isotopomers (IMes)2Ru(Cl)(D)(CO) (1-d1) and [(IMes)2Ru(D)(CO)][BAr′4] (4-d1), respectively, with the rate of formation of 4-d1 at least 28 times faster than the con...}, number={6}, journal={ORGANOMETALLICS}, author={Lee, John P. and Ke, Zhuofeng and Ramirez, Magaly A. and Gunnoe, T. Brent and Cundari, Thomas R. and Boyle, Paul D. and Petersen, Jeffrey L.}, year={2009}, month={Mar}, pages={1758–1775} }