VEPES/XAS/DFT STUDIES OF ET SITES IN BIOINORGANIC CHEMISTRY

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来源获得了主要资金， 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。 在我们以前的建议进行的研究中，我们一直采用可变能量光电子能谱在价和金属2 p区域探索电子弛豫，电子结构的变化后，电离的减少网站。到目前为止，这已被应用到Fe（SR）4网站，其中大的电子弛豫（配位体的M d CT）限制了氧化的电荷变化，并大大降低了几何形状的变化（即网站的重组能）。我们现在正在完成对一系列单核Fe络合物的研究，其中我们研究了从高到低自旋和配位数增加（四面体与八面体）以及配体变化的影响，以了解血红素连接对[Fetpp（imH）2]络合物中电子弛豫的贡献。我们现在建议将我们对bis-Im血红素复合物的PES研究扩展到bis-met Fe（THT）2（tpp）复合物和细胞色素c模型复合物（Fe（C5-Im）（tpp）（THS）.C6H6）其中，我们将通过DFT计算、扩展电荷分解和价键构型来定量met配体对电子弛豫的影响，并将这些结果扩展到cyt B与cyt c的电子弛豫互动分析除了血红素电子转移网站的PES研究，我们将研究共价和电子离域和它们的贡献，在蓝铜，铜，和Fe 4S 4相关的模型复合物的电子弛豫。

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. In studies performed during our previous proposals, we have been employing variable energy photoelectron spectroscopy in the valence and metal 2p regions to explore electronic relaxation, the change in electronic structure upon ionization of a reduced site. Thus far, this has been applied to Fe(SR)4 sites where the large electronic relaxation (ligand to M d CT) limits the charge change on oxidation and greatly reduces the geometry change (i.e. the reorganization energy of the site). We are now completing studies on a series of mononuclear Fe complexes in which we examined the effects of going from high to low spin and increased coordination number (tetrahedral vs. octahedral) as well as ligand variation to understand the contribution of heme ligation to electronic relaxation in the [Fetpp(imH)2] complex. We are now proposing to extend our PES studies of the bis-Im heme complex to the bis-met Fe(THT)2(tpp) complex and a cytochrome c model complex (Fe(C5-Im)(tpp)(THS).C6H6) where we will quantitate the effect of the met ligands on electronic relaxation and extend those results to electronic relaxation of cyt b vs. cyt c through DFT calculations and extended charge decomposition and valence bond configuration interaction analyses. In addition to PES studies of heme electron transfer sites, we will investigate covalency and electron delocalization and their contribution to electronic relaxation in blue copper, CuA, and Fe4S4 related model complexes.