sensitizers employed. The cyclopropene derivatives were produced in the cases of the DCA and TPP+ sensitizations and a solvent adduct was obtained for the TPP+ sensitization reaction. The difference in products is explained by the rates of the back electron transfer from the electron accepted sensitizers to the radical cation intermediates. In the DCA sensitization, the absorption band of the diazoalkene
在 2,4,6-三苯基
吡喃四
氟硼酸盐 (
TPP+) 或
9,10-二氰基蒽 (DCA) 作为敏化剂的存在下,
3H-吡唑被光解。所获得的产品因所使用的敏化剂而异。在DCA和
TPP+敏化的情况下产生了环
丙烯衍
生物并且获得了用于
TPP+敏化反应的溶剂加合物。产物的差异可以通过从接受电子的敏化剂到自由基阳离子中间体的背电子转移速率来解释。在 DCA 敏化中,观察到重氮烯烃的吸收带,但在
TPP+敏化中未观察到。从这些结果可以看出,DCA 敏化反应的背电子转移速率明显快于
TPP+敏化反应的背电子转移速率。