Steroids as Molecular Photonic Wires. <i>Z </i>→ <i>E</i> Olefin Photoisomerization by Intramolecular Triplet−Triplet Energy Transfer with and without Intervening Olefinic Gates<sup>1</sup>
作者:Larry D. Timberlake、Harry Morrison
DOI:10.1021/ja9808595
日期:1999.4.1
3β-((dimethylphenylsilyl)oxy)-17-(Z)-ethylidene-6-methylene-5α-androstane (3a), and 3α-((dimethylphenylsilyl)oxy)-17-(Z)-ethylidene-6-methylene-5α-androstane (3b) have been prepared. The triplet−triplet excited-state energy transfer (TTET) that occurs from the C3 aryl “donor” group to the C17 ethylidene “acceptor” has been studied in detail at 10 mM steroid concentration. Irradiation with 266 nm light results
类固醇 3β-((二甲基苯基甲硅烷基)氧基)-17-(Z)-亚乙基-5α-雄甾烷 (1), 3β-((二甲基苯基甲硅烷基)氧基)-17-(Z)-亚乙基-5-雄甾烷 (2), 3β-((二甲基苯基甲硅烷基)氧基)-17-(Z)-亚乙基-6-亚甲基-5α-雄甾烷(3a)和3α-((二甲基苯基甲硅烷基)氧基)-17-(Z)-亚乙基-6-亚甲基- 5α-雄甾烷 (3b) 已制备。已经在 10 mM 类固醇浓度下详细研究了从 C3 芳基“供体”基团到 C17 亚乙基“受体”发生的三重态-三重态激发态能量转移 (TTET)。用 266 nm 光照射导致 C17 亚乙基的 Z → E 烯烃异构化,这是内部和内部 TTET 的结果。对于 1、2、3a 和 3b,ΦZ→E = 0.037、0.018、0.028 和 0.004。这些化合物和适当模型的详细动力学分析,添加和不添加烯烃猝灭剂,提供一组完整的速率常数,这些常数是相对于假定的