Intramolecular energy transfer between chromophores separated by a rigid steroid bridge——Ⅰ.Singlet a

来源 :Acta Chimica Sinica(English Edition) | 被引量 : 0次 | 上传用户:luo_123
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Intramolecular transfer of both singlet and triplet electronic excitation between thenaphthalene moiety and the carbonyl group in 3β-(1-naphthyl)acetoxy-⊿~5-androsten-17-onewas studied.Irradiation with 280 nm light selectively leads to excitation of the naphthalene moiety.Transfer of the singlet excitation from the naphthalene moiety to the carbonyl group occurs by dipole-dipole resonance interaction.The measured rates for such energy transfer in several solvents agreewith that calculated from Frster equation.After efficient intersystem crossing,the carbonyl grouptransfers triplet excitation back to the naphthalene moiety via electron exchange mechanism.Thecombination of singlet and triplet energy transfer with the high efficiency of intersystcm crossing ofcarbonyl group results in the phosphorescence enhancement of naphthalene moiety. Intramolecular transfer of both singlet and triplet electronic excitation between thenaphthalene moiety and the carbonyl group in 3β- (1-naphthyl) acetoxy-⊿ ~ 5-androsten-17-onewas studied. Irradiation with 280 nm light selectively induced to excitation of the naphthalene moiety . Transfer of the singlet excitation from the naphthalene moiety to the carbonyl group occurs by dipole-dipole resonance interaction. The measured rates for such energy transfer in several solvents agree with that calculated from Frster equation. After efficient intersystem crossing, the carbonyl grouptransfers triplet excitation back to the naphthalene moiety via electron exchange mechanism. The combination of singlet and triplet energy transfer with the high efficiency of intersystcm crossing of carbonyl group results in the phosphorescence enhancement of naphthalene moiety.
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