ELECTRONIC STRUCTURE OF FE-OXO AND MN-OXO COMPLEXES

现代量子化学方法可以用于理论分析。 代表性Mn-氧代和 与生物学相关的铁氧配合物。 量子力学密度 泛函方法用于描述和分析重要性质 活动现场。 最近，我们的小组结合了密度泛函 一种较长射程的静电描述方法 环境 我们的目的是详细了解 这些系统的化学键合、磁性和能量学， 并将其与底层电子结构联系起来， 氧化态、配体环境和几何形状。 大目标 （1）对Mn-氧代二聚体进行计算， 四聚体复合物来表征不同的氧化态， 可能与水氧化相关的配位几何形状， 分子氧析出如在氧析出复合物中发生的 (OEC)植物和蓝藻中的光系统II。 (2)执行 Fe-O二聚体的电子结构计算 含有水、羟基、氧代和羧酸根桥连基团的络合物， 以及末端氮和/或氧配体。 将进行比较 计算出的磁场和光谱特性 合成Fe-O系统的实验研究，并与计算和 包括核苷酸在内的酶活性位点的实验性质 还原酶（RR）和血红蛋白（Hr）以及甲烷单加氧酶。量子 机械几何优化将用于活性部位， 合成模型系统 (3)进一步发展和应用耦合 大自旋耦合的密度泛函/静电方法 含锰氧和铁氧的过渡金属配合物 中心.

Modern quantum chemical methods can be employed for theoretical calculations of the electronic structures of representative Mn-oxo and Fe-oxo complexes relevant to biology. Quantum mechanical density functional methods are used to describe and analyze important properties of the active site. Recently, our group combined the density functional approach with an electrostatic description of the longer range environment. Our purpose is to develop a detailed understanding of chemical bonding, magnetic properties, and energetics of these systems, and to relate these to the underlying electronic structure as a function of oxidation state, ligand environment and geometry. Major goals of this project are: (1) To perform calculations on Mn-oxo dimer and tetramer complexes to characterize different oxidation states and coordination geometries that may be relevant for water oxidation and molecular oxygen evolution as occurs in the oxygen evolving complex (OEC) of photosystem II in plants and cyanobacteria. (2) To perform electronic structure calculation on well defined model Fe-O dimer complexes containing aquo, hydroxo, oxo and carboxylate bridging groups, and terminal nitrogen and/or oxygen ligands. Comparisons will be made of calculated magnetic and spectroscopic properties with current experimental studies of synthetic Fe-O systems, and with calculated and experimental properties of enzyme active sites including ribonucleotide reductase (RR) and hemerythrin (Hr), and methan monooxygenase. Quantum mechanical geometry optimization will be used on active site and synthetic model systems. (3) to further develop and apply the coupled density functional/electrostatic methodology on large spin coupled transition metal complexes containing manganese-oxo and iron-oxo centers.