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: 6607885
• 负责人: Louis Noodleman
• 金额: $ 6.17万
• 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 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6607885
• 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 代表性 Mn-oxo 和 Mn-oxo 的电子结构的计算 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属性 的活性位点。 最近，我们组结合了密度泛函 具有较长范围的静电描述的方法 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， 并将这些与底层电子结构作为函数联系起来 氧化态、配体环境和几何形状。 主要目标 该项目是：（1）对Mn-oxo二聚体进行计算 四聚体复合物来表征不同的氧化态和 可能与水氧化相关的配位几何形状 氧放出络合物中发生的分子氧放出 植物和蓝细菌中光系统 II 的 OEC（OEC）。 (2) 执行 明确模型 Fe-O 二聚体的电子结构计算 含有水合、羟基、氧代和羧酸酯桥连基团的配合物， 和末端氮和/或氧配体。 将会进行比较 计算出的磁和光谱特性与电流的关系 合成 Fe-O 体系的实验研究，以及计算和 包括核糖核苷酸在内的酶活性位点的实验特性 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动场地和 综合模型系统。 (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 含有锰氧和铁氧的过渡金属配合物 中心。