Effects of molecular organization on photophysical behavior. 2. Photoelectrochemical and photocurrent quantum yield studies of the Langmuir-Blodgett monolayers of some surfactant porphyrins
Effects of molecular organization on photophysical behavior. 2. Photoelectrochemical and photocurrent quantum yield studies of the Langmuir-Blodgett monolayers of some surfactant porphyrins
复制标题
分子组织对光物理行为的影响。
作者：
B. Choudhury;and Alan C. Weedon;J. Bolton
介绍了两种新型表面活性剂羧基卟啉的光电化学性质。表面活性卟啉沉积在SnO2半导体表面表现出不同寻常的光电化学效应：在具有富电子侧链的卟啉的修饰光电极电池中产生大量稳定的光电流/光电压。这被解释为由于在被照亮的界面上的电子注入增强了，这是由于在这些链中通过键的电子隧穿增强了。从荧光猝灭测量中获得的电子转移速率常数（ket）与这些模型化合物的光电流量子产率大致一致。所有的模型卟啉都表现出相同的ph函数。当用非荧光基团表面活性化合物二酰基磷脂酰胆碱稀释它们的单层时，所有化合物的光电流量子产率都得到了提高。这被解释为最小化t的结果。
The photoelectrochemistry of two new groups of surfactant carboxyporphyrins is described. The surface active porphyrins deposited onto a SnO2 semiconductor surface exhibit an unusual photoelectrochemical effect: a substantial and stable photocurrent/photovoltage is generated in modified photoelectrode cells that possess porphyrins with electron-rich side chains. This is interpreted as resulting from enhanced electron injection at the illuminated interface, resulting from an enhanced through bond electron tunneling in these chains. The estimated electron-transfer rate constants (ket) obtained from fluorescence quenching measurements roughly agreed with the photocurrent quantum yields for these model compounds. All the model porphyrins behaved identically as a function of pH. An enhanced photocurrent quantum yield was exhibited by all the compounds on diluting their monolayers with dioleoylphosphatidylcholine, a nonfluorophore surface active compound. This is interpreted as resulting from minimization of t...