Supramolecular Photoreactor

本项目重点研究了基于二维超分子组装的人工光合作用的仿生方法。电荷转移（CT）配合物是人工光合作用和光导电材料中常用的电荷分离器件。二维超分子组合。双层膜和Langmuir-Blodgett膜是设计CT复合物的合适人选。基于双层膜的“伪晶体工程”，我们成功地在水性双层膜中定制了疏水联苯片段和亲水紫蛋白头之间的分子间CT复合物。亲水性紫蛋白头和邻近分子的疏水性芳香族部分在倾斜的分子取向上紧密排列。在C12BphC5V2+双层水溶液中，CT配合物在460nm处有较宽的吸收带，而C8BphC10V2+水溶液在可见光区无吸收。在CT复合物的可见光照射下，还发现了长寿命的紫外光自由基。利用多离子络合物技术在ITO电极上制备的C12BphC5V2+的Langmuir-Blodgett膜清楚地显示出Viologen基团的可逆氧化还原反应，并且LB膜有效地将电子从电极介导到氧化还原黄素酶（diaphorase）。研究了光化学生成的紫外光自由基对脱氢酶和NAD的光化学还原作用。

This project focused a biomimetic approach of artificial photosynthesis based on two-dimensional supramolecular assemblies. Charge transfer (CT) complexes are often used as a charge separation device in an artificial photosynthesis and photo conductive materials. Two-dimensional supramolecular assemblies.e.g. bilayr membranes and Langmuir-Blodgett films, are suitable candidates for designing CT complexes. Based on "pseudo crystal engineering" of bilayr membranes, we succeeded tailoring an intermolecular CT complex between a hydrophobic biphenyl moiety and a hydrophilic viologen head in an aqueous bilayr membrane.The hydrophilic viologen head and the hydrophobic aromatic segment of the adjacent molecule was expected to be closely packed in the tilted molecular orientation.A broad absorption band at 460nm attributed to a CT complex was observed in the aqueous bilayr solution of C12BphC5V2+, whereas a water solution of C8BphC10V2+ had no absorption in visible region. A long lived viologen radicals was also found on visible light irradiation of the CT complex. Langmuir-Blodgett films of C12BphC5V2+ prepared by the polyion complex technique on ITO electrodes clearly showed reversible redox reaction of the Viologen group and the LB film effectively mediated electrons from the electrode to a redox flavin enzyme, diaphorase. Photochemical reduction of diaphorase and NAD by the photochemically generated viologen radical was investigated.