INOR 730 |
| The spectroscopic, electronic, and DNA binding characteristics of two ruthenium complexes bases on enediyne ligands, 2,3-bis(phenylethynyl)-1,4,8,9-tetraaza-triphenylene (bptt) and 2,3-bis(4-tert-butyl-phenylethynyl)-1,4,8,9-tetraaza-triphenylene (tbptt) have been investigated. Photophysical studies reveal that [Ru(bptt)(phen)2]2+ and [Ru(tbptt)(phen)2]2+, like other light switch molecules, possess two distinct MLCT excited states, one centered on the phenanthroline component of the three ligands and one involving the pyrazylenediyne portion of the bppt ligand. In ethanol, luminescence is only observed for the first of these states. In an aqueous environment, biexexponential decay kinetics show luminescence from both states. Upon addition of calf thymus DNA, the quantum yield increases by a factor of 9 for the bptt complex, due to solvent shielding, allowing this complex to be used as a DNA reporter. Intrinsic luminescence was used to determine the binding affinity of the bptt complex for DNA (Ka = 3.3 X 104) and to verify the binding mode is intercalative. |
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Bioinorganic: DNA and RNA
7:00 PM-10:00 PM, Tuesday, March 27, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Sci-Mix
Division of Inorganic Chemistry |