Theoretical Studies of Structure and Reactions of Transition Metal Atoms, Ions, Complexes and Clusters

埃默里大学的Keiji Morukuma在理论和计算化学项目的支持下，使用从头算、密度泛函数和ONIOM（混合分子轨道加分子轨道或分子力学）方法研究过渡金属团簇和复合物的结构和反应。该方法允许将复杂的真实配体包含到计算中，将开发和校准大型过渡金属配合物。此外，还将测试ionom - pcm（极化连续介质模型）方法，并将其用于研究溶液中的有机金属反应。与实验化学家保持密切联系，同时探索实验相关问题。二氢、炔和烯烃与裸过渡金属团簇的气相反应，以及C-C、C-H和分子氮键的激活，以及骨架重排，在三核钌配合物上将被研究，目的是检查金属团簇可以催化在单一过渡金属中心上不可能发生的反应。此外，还将阐明有机金属化学中几个重要反应的机理，包括单核过渡金属配合物的各种反应和全均相催化循环，包括(a)烯烃共聚，(b)不饱和烃的元素-元素加成，(c)金属-配体多键的利用，(d)过渡金属催化的环异构化，(e)烯丙基化合物与甲酸或金属氢化物的反应。以及烯烃的分解。从这项研究中获得的关于反应中间体和过渡态的结构、光谱性质和能量的知识有望促进对催化剂的基本理解，并有助于新催化剂的逻辑设计，从而更好地控制复杂的化学反应。这个计算研究项目补充了实验化学的努力，并有望促进对复杂化学反应的基本理解。虽然过去已经开发了许多工业催化过程，但化学工业正在努力转向使用清洁均相过程的催化剂。设计高效的催化剂是计算化学可以在化学工业中产生重大影响的领域之一。

Keiji Morukuma of Emory University is supported by the Theoretical and Computational Chemistry Program to study the structure and reactions of transition metal clusters and complexes using ab initio, density functional, and ONIOM (hybrid molecular orbital plus molecular orbital or molecular mechanics) methods. The ONIOM method, which allows inclusion of complex real ligands into computations, will be developed and calibrated for large transition metal complexes. As well, the ONIOM-PCM (polarized continuum model) method will be tested and employed to study organometallic reactions in solutions. Close contact with experimental chemists will be maintained, while experimentally relevant problems are explored. Gas phase reactions of dihydrogen, alkynes, and alkenes with bare transition metal clusters and C-C, C-H and molecular nitrogen bond activation, along with skeletal rearrangement, on trinuclear ruthenium complexes will be studied, with the goal of examining metal clusters that can catalyze reactions not possible on a single transition metal center. As well, the mechanisms of several important reactions in organometallic chemistry will be elucidated, encompassing a wide variety of reactions of mononuclear transition metal complexes and full homogeneous catalytic cycles including (a) olefin copolymerization, (b) element-element addition to unsaturated hydrocarbons, (c) utilization of metal-ligand multiple bonds, (d) transition metal catalyzed cycloisomerizations, (e) reaction of allylic compounds with formic acid or metal-hydride, and olefin metathesis. The knowledge of structure, spectroscopic properties, and energies of reaction intermediates and transition states that will be gained from this research is expected to promote fundamental understanding as well as aid logical design of new catalysts for better control of complicated chemical reactions. This computational research project complements efforts in experimental chemistry, and is expected to promote the fundamental understanding of complex chemical reactions. Although many industrial catalytic processes have been developed in the past, the chemical industry is trying hard to switch to catalysts using clean homogeneous processes. Designing efficient catalysts is one of the areas where computational chemistry can make a substantial impact in the chemical industry.