New multinuclear metal catalysts for the light-driven activation of water and reduction of CO2

首次制备了活化水和一氧化碳的异寡核金属有机化合物。目前正在研究它们的（光）催化性能并优化反应条件。根据所获得的经验，将合成新的优化催化剂，用于生产氢和氧（氢燃料电池燃料）以及CO或HCOOH作为C1构建块。在这些系统中，光活性单元与催化活性单元的连接起着主要作用。定向良好的光电子转移（PET）可以在这些光催化剂中提供所需的电子等价物或空穴。对氧化离子氧化为O2及其反反应（O2为H2O或H2O2）进行了研究，特别是对Hangman-型和pacman -型化合物。取代基和催化金属中心的具体引入将决定反应的方向。一方面选用钌多吡啶类化合物，另一方面选用高价锰铁卟啉类化合物作为催化活性单元。利用超分子化合物研究还原过程，特别是光活化还原CO2。扩展卟啉大环作为桥接配体，并以连接捕获光能的光活性中心与催化活性金属中心的方式排列。通过对光、pH值、取代基和其他参数对计划有机转化的可控性的研究，可以得到精确的产物选择性。此外，通过分离和表征反应中间体，将提供对流逝过程和机制的新见解。

First hetero-oligonuclear metal-organic compounds for the activation of water and carbon monoxide have been prepared. Their (photo)catalytic properties are currently investigated and reaction conditions are optimized. With the experiences gained new optimized catalysts for the production of hydrogen and oxygen (hydrogen fuel cell fuels) as well as CO or HCOOH as C1 building blocks shall be synthesized. In those systems, the connection of a photoactive unit with a catalytic active unit plays a major role. A well-directed photo-electron-transfer (PET) enables the provision of the required electron equivalents or holes in these photo-catalysts.The oxidation of oxid-ions to O2 and its backreaction (O2 to H2O or H2O2), respectively, are to be investigated especially with compounds of the Hangman- and Pacman-type. The specific introduction of substituents and catalytic metal center will determine the direction of the reaction. On the one hand, ruthenium polypyridyl compounds and on the other hand high-valent manganese and iron porphyrinoids shall be employed as catalytic active unit. Studies on reduction processes, especially the light-activated reduction of CO2, are to happen using supramolecular compounds. Extended porphyrinic macrocycles function as a bridging ligand and are arranged in a way to connect a photoactive center capturing light energy with a catalytic active metal center.The investigation of the controllability of the planned organic transformations by light, pH value, substituents and other parameters is supposed to lead to a precise product selectivity. Additionally, new insights into the elapsing processes and mechanisms shall be provided by isolation and characterization of reactive intermediates.