Aspects of artificial photosynthesis. Photosensitized electron transfer across bilayers, charge separation, and hydrogen production in anionic surfactant vesicles
Aspects of artificial photosynthesis. Photosensitized electron transfer across bilayers, charge separation, and hydrogen production in anionic surfactant vesicles
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DOI：
10.1021/ja00400a002
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发表时间：
1981-05
影响因子：
15
通讯作者：
M. S. Tunuli;J. Fendler
中科院分区：
文献类型：
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作者：
M. S. Tunuli;J. Fendler
用稳态光解、荧光猝灭和纳秒激光光解方法研究了在带负电荷的磷酸双十六烷基酯（DHP）、表面活性剂囊泡存在下，三（2，2 '-联吡啶）钌阳离子Ru（bpy）/sub 3//sup 2 +/与甲基紫精MV/sup 2 +/之间的光敏电子转移.已经使用了四种不同的基质-表面活性剂囊泡组织。在系统I中，Ru（bpy）/sub 3//sup 2 +/被连接在DHP囊泡的外表面，MV/sup 2 +/被放置在DHP囊泡的内表面。在系统II中，MV/sup 2 +/吸附在DHP囊泡的外表面，Ru（bpy）/sub 3//sup 2 +/吸附在囊泡的内表面。在系统Ⅲ中，Ru（bpy）/sub 3//sup 2 +/和MV/sup 2 +/均位于DHP囊泡的外表面。在体系IV中，Ru（bpy）/sub 3//sup 2 +/和MV/sup 2 +/均定位于DHP囊泡的内表面。在系统III和IV中的表面活性剂囊泡的表面上已经观察到非常有效的电子转移。在体系I中，在外加EDTA存在下，电子从受激态Ru（bpy）/sub ~ 3//sup ~ 2 +/穿过囊泡双层转移到MV/sup ~ 2 +/，形成还原甲基紫精MV/sup ~+/，转换率高达75%，量子效率more »为2.40 x 10/sup -2/。如果再加上。10/sup-5/ M PtO/sub 2/包埋在系统I（MV/sup +/）的DHP囊泡内部。迅速重整并伴随氢析出。该系统的光解导致在非常低的化学计量Ru（bpy）/sub 3//sup 2 +/、MV/sup 2 +/和PtO/sub 2/浓度下仅EDTA的净消耗。这些过程的动力学已经确定，并讨论了它们与光化学太阳能转换的关系。«少
Photosensitized electron transfer from tris(2,2'-bipyridine)ruthenium cation, Ru(bpy)/sub 3//sup 2 +/, to methylviologen, MV/sup 2 +/, has been investigated in the presence of negatively charged dihexadecyl phosphate, DHP, surfactant vesicles by steady state photolysis, fluorescence quenching, and nanosecond laser flash photolysis. Four different substrate-surfactant vesicle organizations have been used. In system I, Ru(bpy)/sub 3//sup 2 +/ was attached to the outer and MV/sup 2 +/ was placed onto the inner surfaces of DHP vesicles. In system II, MV/sup 2 +/ was attached to the outer and Ru(bpy)/sub 3//sup 2 +/ to the inner surfaces of DHP vesicles. In system III, both Ru(bpy)/sub 3//sup 2 +/ and MV/sup 2 +/ were localized on the outer surfaces of DHP vesicles. In system IV, both Ru(bpy)/sub 3//sup 2 +/ and MV/sup 2 +/ were localized on the inner surfaces of DHP vesicles. Extremely efficient electron transfers have been observed on the surfaces of surfactant vesicles in systems III and IV. Electron transfer from excited Ru(bpy)/sub 3//sup 2 +/ to MV/sup 2 +/ across the bilayers of vesicles in the presence of externally added EDTA in system I resulted in the formation of reduced methylviologen, MV/sup +/., up to 75% conversion with a quantum efficiencymore » of 2.40 x 10/sup -2/. If additionally approx. 10/sup -5/ M PtO/sub 2/ was entrapped in the interiors of DHP vesicles in system I, MV/sup +/. promptly reformed with concomitant hydrogen evolution. Photolysis of this system leads to the net consumption of only EDTA at very low stoichiometric Ru(bpy)/sub 3//sup 2 +/, MV/sup 2 +/, and PtO/sub 2/ concentrations. Dynamics of these processes have been determined and their relevance to photochemical solar energy conversions is discussed.« less