ORGN 84 |
| We are developing compounds capable of gating sensitivity toward photoinduced charge transfer, making use of the drastic electrochemical changes that accompany the color change in photochromic rearrangements. Photochromes with long wavelength isomers (LW) capable of acting as a photooxidant but with short wavelength isomers (SW) less capable of doing so are sought. This necessitates photochromes that revert only thermally and that have excited state reduction potentials that are more positive in LW than in SW. This poses a substantial challenge: the shift in absorbance to longer wavelength mitigates against increases achieved in ground state reduction potential, requiring even more positive reduction potentials upon isomerization to see the desired effect in the excited state. The parent perimidinespirohexadienone photochrome is reported to meet these requirements, but with very modest differences in excited state reduction potentials. Analogs with more electron-deficient naphthalene moieties are being prepared to increase this difference and establish gating of PICT.
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
1:00 PM-5:20 PM, Sunday, 10 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |
