INOR 670 |
| As part of our effort to prepare bifunctional ketone transfer hydrogenation catalysts that utilize an inner-sphere mechanism we prepared (Terpy)Ru(Pyo)2(OH2) (1), (Terpy)Ru(Pyd)2(OH2) (2), and (Terpy)Ru(Azi)(AziH)Cl (3) (where Terpy = 2,2':6',2"-terpyridine, Pyo = 2-pyridinate, Pyd = 2-pyrrolidinonate, Azi = 7-azaindolate) that function with and without base co-catalysts. Reaction kinetics and substrate competition experiments indicate that these catalysts indeed form intermediates bearing proton and hydride acceptor sites that support hydrogen transfer to and from coordinated substrates. Analogs of complexes 1 and 2 have been prepared with substituted Pyo and Terpy ligands, respectively, and compared as transfer hydrogenation catalysts. Ligand substitution effects suggest that a shift of electron density away from the hydride trajectory enhances activity. Attempts to model catalytic intermediates and the transition state of hydride transfer at the density functional level will be presented. |
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Characterization and Applications of Coordination Compounds
7:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Inorganic Chemistry |