ELECTRONIC STRUCTURE OF FE-OXO AND MN-OXO COMPLEXES

FE-OXO 和 MN-OXO 配合物的电子结构

• 批准号: 6180418
• 负责人: Louis Noodleman
• 金额: $ 16.99万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180418
• 关键词: active sites; carbonyl compound; electron density; enzyme complex; hemerythrin; iron; manganese; methane monooxygenase; photosynthetic bacteria; photosynthetic reaction centers; photosystem; plants; protein structure function; quantum chemistry; ribonucleotide reductase

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.

现代量子化学方法可用于理论研究 具有代表性的锰氧杂多酸的电子结构计算 与生物学相关的铁-氧配合物。量子力学密度 函数方法用于描述和分析重要的属性 活动站点的。最近，我们课题组将密度泛函 用较长距离的静电描述的方法 环境。我们的目的是详细了解 这些体系的化学键、磁性和能量学， 并将它们作为函数与底层电子结构相关联 氧化状态、配位环境和几何构型。的主要目标 本项目是：(1)对锰氧二聚体进行计算， 四聚体络合物表征不同的氧化状态和 配位几何可能与水的氧化和 在放氧复合体中发生的分子放氧 植物和蓝藻中光系统II的(OEC)。(二)履行 精确模型Fe-O二聚体的电子结构计算 含有水、羟基、氧和羧酸桥基的络合物， 和末端氮和/或氧配体。我们将进行比较 计算的磁学和光谱性质与电流 合成Fe-O体系的实验研究及计算和计算 含核糖核酸酶活性部位的实验性质 还原酶(RR)、氯氰菊酯(HR)和甲氧基单加氧酶。量子 机械几何优化将在活动现场使用，并 合成模型系统。(3)进一步开发和应用联轴器 大自旋耦合的密度泛函/静电方法 含锰氧和铁氧过渡金属络合物 中锋。