MULTI-EDGE XAS INVESTIGATION OF MONO AND BINUCLEAR CU- AND FE-CONTAINING BIOMIME

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。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 研究中心，而研究中心不一定是研究者所在的机构。 我们提出了一系列的Cu和Fe的仿生配合物的多边缘X射线吸收研究，以深入了解非无辜的性质的金属配体成键相互作用。虽然这些配合物含有非生物配体与膦，phosphido，和氨基基团，除了生物硫醇和硫醚基团，他们提供了一个系统的和可调的方式来探测电子和几何结构的贡献，生物氧化还原过程中的电子转移铜网站和小分子活化中心，如氢化酶和固氮酶。提出的XANES分析的上升沿功能在金属L-边缘和配体K-边缘将提供直接的实验信息的配体为基础的氧化还原化学和金属配体回捐的程度。金属K边的EXAFS分析将用于参照小分子晶体学表征样品完整性。光谱数据的解释将得到电子结构计算的帮助。此外，理论的计算水平（基集和泛函）将根据金属和配体特征进行校准，这些特征将通过实验从前边缘和上升边缘特征确定。

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. We propose multi-edge X-ray absorption studies on a series of Cu and Fe containing biomimetic complexes to gain insights into the non-innocent nature of metal-ligand bonding interactions. While these complexes contain abiotic ligands with phosphine, phosphido, and amido groups in addition to biotic thiol and thioether groups, they provide a systematic and tunable way to probe electronic and geometric structure contributions to biological redox processes in electron-transfer CuA-sites and small-molecule activation centers such as hydrogenases and nitrogenases. The proposed XANES analyses of rising-edge features at metal L-edge and ligand K-edges will provide direct experimental information about the ligand-based redox chemistry and the extent of metal-to-ligand back-donation. The EXAFS analysis at the metal K-edge will be used to characterize the sample integrity with reference to small-molecule crystallography. The interpretation of the spectroscopic data will be aided by electronic structure calculations. Furthermore, the computational level of theory (basis set and functional) will be calibrated to metal and ligand characters that will be experimentally determined from pre-edge and rising-edge features.