含有两个香豆素的α,ω-双发色团长链化合物的光环合加成反应

本文研究了含有两个香豆素的α,ω双发色团长链化合物在溶液中的光环合加成反应, 结果表明: 标题化合物有着不同于单体香豆素的光化学行为, 即它能在低浓度及非极性溶剂内发生分子内的光二聚反应。此外, 通过高分辨核磁共振谱对产物立体化学的研究发现, 反应无论是在极性溶剂或非极性溶剂中进行或反应中是否加入了三重态敏化剂。所得产物均为顺式头-头分子内二聚结构。对反应机制进行了初步讨论。

Photocycloaddition reaction of the compound containing two coumarin groups linked by long-chain

Photocycloaddition of the title compound 1 which contains two coumarin groups linked by a long-chain ether has been studied in this article. It was found that 1 Shows different photo chemical behaviours from that of monomeric coumarin, i.e., in the concentration less than 10^-^4mol·L^-^1 and in the nonpolar solvent intramolecular photo- dimerization can occur, the steric structure of the product was determined by the spectra of ^1H NMR, ^1^3C NMR and 2D-J, which show it as an intramolecular syn-head to head dimer. Further investigation indicated that the stereospecific fashion of the photodimer is independent of the solvent polarity wa well as triplet sensitizer. The photocycloaddition mechanism of compound 1 was preliminaryly discussed.