MECHANISTIC CONSIDERATIONS IN THE PHOTODISPROPORTIONATION OF MU-OXO-BIS((TETRAPHENYLPORPHINATO)IRON(III))
MECHANISTIC CONSIDERATIONS IN THE PHOTODISPROPORTIONATION OF MU-OXO-BIS((TETRAPHENYLPORPHINATO)IRON(III))
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DOI：
10.1021/ja00296a013
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发表时间：
1985-01-01
影响因子：
15
通讯作者：
RICHMAN, RM
中科院分区：
文献类型：
--
作者：
PETERSON, MW;RIVERS, DS;RICHMAN, RM
本文研究了二氧代双（四苯基卟啉合）铁（Ⅲ）[（FeTPP）20]的光化学。连续和闪光光解都建立了光化学反应，形成亚铁络合物FeTPP和铁基络合物FeOTTP。使用三苯基膦捕获铁基复合物导致FeTTP的净形成。在足够高的灯强度（I_0> 10 ~（-8）einstein）下，发现该反应与强度有关，这些数据已被计算机拟合到光致猝灭机理。烯烃（环己烯和四甲基乙烯）被发现与铁络合物在高强度下反应，产生烯醇。在阳光下，在分子氧存在下进行环己烯的催化氧化，以产生2-环己烯-1-酮，其中（FeTPP）20的转化率> 1000。没有温度依赖性。在λ 350-440 nm范围内，量子产率随波长的减小而增大.这有利于光化学从一个高度扭曲的金属到金属的电荷转移状态。几个共同的元素出现在太阳能转换的最有前途的策略的研究。从半导体电极到光合作用，光子能量最初转换为电荷分离。有效的机制可以防止这种能量在逆反应中作为热量立即损失。无论是通过能带弯曲1还是随后的电子转移步骤，2小的
The photochemistry of ji-oxo-bis ((tetraphenylporphinato) iron (III))[(FeTPP) 20] has been studied. Both continuous and flash photolysis establish a photochemical disproportionation to form the ferrous complex FeTPP and the ferryl complex FeOTTP. Using triphenylphosphine to trap the ferryl complex results in a net formation of FeTTP. This reaction is found to be intensity dependentat sufficiently high lamp intensities (I0> 10'8 einstein), and these data have been computer fitted to the photodisproportionation mechanism. Olefins (cyclohexene and tetramethylethene) were found to react with the ferryl complex at high intensities to yield the ene-ol. Catalytic oxidation of cyclohexene was performed in the presence of dioxygen in sunlight to yield 2-cyclohexen-1-one with> 1000 turnovers of the (FeTPP) 20. There is no temperature dependence. The quantum yield increases with decreasing wavelength in the range X 350-440 nm. This favors photochemistry from a highly distorted metal-to-metal charge-transfer state.Several common elements emerge from a study of the most promising strategies for solar energy conversion. From semi-conductor electrodes to photosynthesis, photon energy is initially converted to charge separation. Efficient mechanisms prevent immediate loss of this energy as heat in a back reaction. Whether by band bending1 or subsequent electron transfer steps, 2 a small