XAS STUDIES OF A METHANE HYDROXYLATING BINUCLEAR MODEL COMPLEX

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。合成并表征了一种新型双核铁模型配合物，该配合物能高效地将甲烷转化为甲醇。其催化中间体的相对不稳定性和较短的寿命，迄今为止，排除了获得该中间体的结构数据。这里建议利用X射线吸收光谱（边缘和EXAFS）来解决电子和几何结构。该中间体被认为含有混合价位点，具体地被认为是由桥接至六配位铁酰基-氧代部分的六配位亚铁中心组成。如提案所述，通过谨慎使用从催化前体和衰变产物数据以及从其他特定模型络合物中获得的信息，将分离出这种混合物对中间体的边缘前、边缘和EXAFS数据的相对贡献。该复合物的表征具有几个重要的意义：在工业上将甲烷转化为甲醇，作为无机模型复合物，以及作为甲烷单加氧酶的甲醇转化活性位点的模型。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A new binuclear iron model complex has been synthesized and characterized, which converts methane into methanol with high efficiency. The relative instability and short lifetime of its catalytic intermediate has thus far precluded obtaining structural data on this intermediate. It is proposed here to utilize x-ray absorption spectroscopy (edge and EXAFS) to address the electronic and geometric structure. The intermediate is thought to contain a mixed-valent site, specifically considered to be comprised of a six-coordinate ferrous center bridged to a six-coordinate ferryl-oxo moiety. Through prudent use of information obtained from data of the catalytic precursor and decay product, as well as from additional specific model complexes, the relative contributions of this mixture to the pre-edge, edge and EXAFS data of the intermediate will be separated, as described in the proposal. The characterization of this complex has several important implications: in the industrial conversion of methane to methanol, as an inorganic model complex, and as a model of the methanol-converting active site of methane monooxygenase.