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利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们建议对一系列含有铜和铁的仿生配合物进行多边X射线吸收研究，以深入了解金属-配体相互作用的非无害性质。虽然这些配合物除了含有生物的硫醇和硫醚基团外，还含有膦、磷和氨基的非生物配体，它们提供了一种系统和可调的方法来探索电子转移CUA中心和小分子激活中心(如氢酶和固氮酶)对生物氧化还原过程的电子和几何结构贡献。对金属L边和配体K边的上升沿特征的XANES分析将为基于配体的氧化还原化学和金属对配体回馈的程度提供直接的实验信息。在金属K边的EXAFS分析将被用来参照小分子结晶学来表征样品的完整性。对光谱数据的解释将借助电子结构计算。此外，理论的计算水平(基组和泛函)将被校准为金属和配体特征，这些特征将通过实验从前缘和上升缘特征确定。

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.