Theoretical Studies of Inorganic and Organometallic Systems

这个无机、生物无机和有机金属化学项目的奖项支持德克萨斯农工大学化学系Michael B. Hall博士在催化方面的理论研究。与催化的四个基本步骤有关的系统将被研究：氧化加成，取代，迁移插入和原子转移。详细动力学的C-H键活化的早期阶段铑羰基配合物将进行研究。将确定连接两个提议的溶剂化中间体的过渡态的性质和能量。其他的研究将集中在镝催化的环化和钌催化的炔和烯烃二聚化。非经典二氢配合物和经典氢化物之间的转化将被模拟。氧的转移和插入将在模拟钼酶的模型系统中进行检查。计算结果将与已知的实验结果进行比较。非局部密度泛函理论（DFT）和多构型自一致场（MCSCF）方法，特别是广义分子轨道方法（GMO2），将用于稳定分子、反应中间体和过渡态的全梯度几何优化。GMO2方法非常适合于过渡金属。更高层次的方法将用于确定势能面上的临界点。许多重要工业反应的催化机理尚不清楚。在这项研究中，分子的电子状态及其反应途径的理论计算将用于开发反应性模型，并将与实验结果进行比较。这有助于改进催化剂的开发。

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports theoretical studies related to catalysis by Dr. Michael B. Hall of the Chemistry Department, Texas A&M University. Systems related to four fundamental steps in catalysis will be investigated: oxidative-addition, substitution, migratory-insertion, and atom transfer. Detailed kinetics of the early stages of C-H bond activation by a rhodium carbonyl complex will be studied. The nature and energy of the transition states connecting two proposed solvated intermediates will be determined. Other studies will concentrate on dirhodium catalyzed cyclizations and ruthenium catalyzed alkyne and alkene dimerizations. Transformations between non-classical dihydrogen complexes and classical hydrides will be modeled. Oxygen transfer and insertion will be examined in a model system that mimics molybdenum enzymes. Calculational results will be compared with known experimental results. Non-local density functional theory (DFT) and multiconfiguration self-consistent field (MCSCF) methods, especially generalized molecular orbital method (GMO2), will be used for full-gradient geometry optimization of stable molecules, reaction intermediates, and transition states. The GMO2 method is well-suited to transition metals. Higher level methods will be used to determine critical points on potential energy surfaces.Detailed mechanisms for catalysis of many important industrial reactions are not known. In this study, theoretical calculations of the electronic states of molecules and their reaction pathways will be used to develop models for reactivity that will be compared to experimental results. This could aid in the development of improved catalysts.