影像科学与光化学 ›› 2000, Vol. 18 ›› Issue (2): 144-149.DOI: 10.7517/j.issn.1674-0475.2000.02.144

• 研究论文 • 上一篇    下一篇

反-4-(4-R-苯乙烯基)吡啶光二聚反应的研究

张文勤, 张西慧, 郑艳, 沈刚, 庄俊鹏   

  1. 天津大学化学系, 天津300072
  • 收稿日期:1999-07-26 修回日期:1999-11-04 出版日期:2000-05-20 发布日期:2000-05-20
  • 通讯作者: 张文勤
  • 基金资助:
    国家自然科学基金资助课题(29602006)

STUDIES ON THE PHOTODIMERIZATION OF trans-4-(4-R-STYRYL)PYRIDINE

ZHANG Wen-qin, ZHANG Xi-hui, ZHENG Yan, SHEN Gang, ZHUANG Jun-peng   

  1. Department of Chemistry, Tianjin University, Tianjin 300072, P. R. China
  • Received:1999-07-26 Revised:1999-11-04 Online:2000-05-20 Published:2000-05-20

摘要: 通过反-4-(4-R-苯乙烯基)吡啶[R=H(Ⅰa),Me(Ⅰb),OMe(Ⅰc),OH(Ⅰd),Me2N(Ⅰe)]在稀盐酸中的光二聚反应合成了4个r-1,c-2,t-3,t-4-1,3-双(4-R-苯基)-2,4-二(4-吡啶基)环丁烷[R=H(Ⅱa),Me(Ⅱb),OMe(Ⅱc),OH(Ⅱd)],除Ⅱa外,其余为新化合物.光二聚反应具有高度立体选择性且几乎是定量完成的.研究发现,随着取代基供电子能力的提高,光二聚反应速率下降.反应的高度立体选择性以及该反应不受空气中氧气影响的事实表明光二聚反应是按激发单重态历程进行的.研究还发现Ⅰa~Ⅰd在有机溶剂中主要发生反-顺异构化反应,随着溶剂极性增加,反-顺异构化速度加快,表明其反-顺异构化反应亦经激发单重态历程.本文检测到了Ⅰa在稀盐酸溶液中的激基缔合物荧光.

关键词: 苯乙烯基吡啶, 光二聚, 激基缔合物, 荧光

Abstract: Four r-1,c-2,t-3,t-4-1,3-bis(4-R-phenyl)-2,4-di(4-pyridyl)cyclobutane [R=H(Ⅱa),Me(Ⅱb),OMe(Ⅱc),OH(Ⅱd)] were synthesized directly with high yield and high stereoselectivity by the photodimerization of trans-4-(4-R-styryl)pyridine [R=H(Ⅰa),Me(Ⅰb),OMe(Ⅰc),OH(Ⅰd),Me2N(Ⅰe)] in HCl solution. It was found that the dimerization speed decreases with increasing the electron donating ability of the substituents. The high yield and high stereoselectivity of the photodimerization as well as it is not affected by the presence of oxygen further confirms this reaction proceeding through an excited singlet state. The excimer fluorescence of Ⅰa in HCl solution was reported.\;

Key words: styrylpyridine, photodimerization, excimer, fluorescence

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