【摘要】 以N,N,N′,N′-四甲基联苯二胺、2,6-二甲氧基萘和2,7-二甲氧基萘为光敏剂,在正己烷溶液中实现了双环[2,2,1]-2,5-庚二烯到四环[2,2,1,0^2,6,0.（3,5）]庚烷的异构化。测定了反应的量子产率。讨论了反应机理。通过激发态的光敏剂与二烯之间的电子转移反应,形成单重态和三重态处于平衡状态的离子自由基对中间体。处于溶剂笼中的三重态离子自由基对经电子反传,产生激发三重态二烯。最后该激发态二烯经分子内[2+2]环合加成反应异构化为四环烷。更多还原

【Abstract】 Isomerization of bicyclo [2, 2, 1]-2,5-hepta-diene to quadricyclo [2, 2, 1, 02.6, 03,5 ]-heptane was investigated using N, N, N’, N’-tetramethylbenzidine, 2,6-dimethoxynaphthalene, and 2,7-dimethoxynaphthalene as photosensitizers. The quantum yields of the isomerization were determined and the reaction mechanism was discussed. An exciplex of radical ion pair is formed as intermediate through electron transfer between excited photosensitizer and diene. There is an equilibrium between the excited singlet and triplet radical ion pair. Excited triplet diene is formed via back electron transfer between radical ion pair within a solvent cage. Finally, the excited diene is converted to quadricyclo [2, 2, 1, 02,6, 03,5] -heptane via intramolecular [2 + 2] cycloaddition.更多还原