光氧化反应的研究Ⅱ.9-苯甲叉芴的电子转移光氧化反应

Studies on Photooxidations Ⅱ. Electron Transfer Photooxidation of 9-Benzylidene Fluorene

芳香族烯烃、芳烃以及稠环芳烃是光氧化反应中的重要研究对象.近来,Foote等对多苯基取代乙烯的光氧化进行了深入的研究并提出芳族烯烃可作为电子给体与氰基蒽等电子受体作用而经历电子转移(ET)光氧化过程,这一新进展已受到广泛重视.继之,Farid亦报道四氰蒽可以顺利进行敏化芳烃的ET型光氧化反应.不过在此前,Bartlett曾报道。

Some sensitizers were used to initiate the photooxidation of 9-benzylidene fluorene(BF). It was found that the sensitizer 9, 10-dicyanoanthracene(DCA) was particularly effective on the reaction, leading to the formation of fluorenone and the corresponding epoxide of BF. The photooxidation was proposed to proceed via electron transfer(ET) mechanism. Some evidences were given from UV spectrometry, cyclic voltammetry as well as Rehm-Weller theory for ET processes. Furthermore an apparent quenching effect of BF on the fluorescence of DCA followed the Stern-Volmer equation, which indicated that the ET photooxidation was diffusion-controlled and was consistent with the ET mechanism suggested.