【摘要】 测定了四苯基卟啉锌和苯醌的四氢呋喃除氧溶液在不同温度下的光诱导电子自旋共振谱,检测到的信号在—100℃时最强,且得到的信号是由苯醌负离子质子化的自由基产生.而没有得到卟啉正离子自由基信号.在体系中加入重原子化合物碘代苯后,信号强度显著减弱,说明离子自由基的产生或卟啉和醌间的电荷转移反应主要是通过卟啉化合物的激发一重态进行的.更多还原

【Abstract】 The reaction of photoexcited Zn-tetraphenylporphyrin with benzoquinone in unaerated tetrahydrogenfuran has been examined by ESR measurement. It reveals that a ESR signal can be observed clearly upon illumination of the solution at the temperature range from -15℃ to -120℃ and the signal intensity reaches its maximum around -100℃, however, is reduced significantly due to the addition of compounds containing heavy atom such as iodobenzene and propyl iodide. An analysis of the structure of the ESR signals observed indicates that it stems from semiquinone anion-radical rather than cation-radical of Zn-tetraphe nylporphyrin. The effect of heavy-atom compounds on the signal intensity leads us to a conclusion that the photoinouced electron transfer between quinone and porphyrin takes place mainly before the relaxation of photoexcited singlet to triplet of porphyrin.更多还原