COLL 15 |
| Harry D. Gafney1, Jose Zambrana Jr.1, Elena Ferloni1, and Jainwei Fan2. (1) Department of Chemistry, City University of New York, Queens College, Flushing, NY 11367, (2) Department of Chemistry, Manhattan College, Riverdale, NY 10471 |
| Ru(II) diimines possessing acid-base sites on the ligand periphery exhibit immense changes in acid-base properties on excitation. Since the equilibrium constants for coordination of diimine ligands is directly proportional to the basicity of the diimine, experiments in this laboratory explore these “complexes as ligands”; specifically whether the immense increase in basicity that occurs on population of the emissive MLCT state, >106, leads to an excited-state coordination chemistry. Spectral and emission quenching data will be presented which indicate that optical excitation of (bpy)2Ru(dpp)2+ in the presence of metal ions leads to excited-state coordination, while in the bimetallic [(bpy)2Ru(CN)(u-CN)Rh(NH3)4Br]2+, where excitation of the “(bpy)2Ru(CN)2 ligand” reduces cyano basicity, excitation leads to a dissociative excited state without consumption of the excitation energy. |
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Symposium in Memory of Arthur W. Adamson
8:30 AM-12:00 PM, Sunday, March 28, 2004 Marriott -- Orange County 4, Oral
Division of Colloid and Surface Chemistry |