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

理论与计算化学项目支持埃默里大学的Keiji Morokuma教授进行过渡金属及其配合物的理论研究。高水平从头算理论计算广泛应用于过渡金属原子、离子、配合物和团簇的结构和反应问题。计算各种化学反应的势能面，包括裸过渡金属离子、原子和简单配合物的气相反应，复杂过渡金属配合物对各种键的激活，有机金属催化剂全催化循环的势能分布，以及过渡金属团簇和团簇配合物的反应。除了标准的从头算分子轨道（MO）方法外，最近由主要研究者开发的集成分子轨道+分子力学（IMOMM）方法和集成MO + MO （IMOMO）方法将用于涉及复杂配体的反应的研究。过渡金属配合物全催化循环的理论研究仍然是对理论家的挑战，将进行以下方面的研究：(1)Pt(0)和Pd(0)配合物对烯烃和炔的硼化；(2)Rh(I)催化剂与手性配体BINAPHOS对烯烃的区域和对映选择性氢甲酰化；(3)Ru配合物对芳酮的村井C-H活化。此外，还研究了Pd（II）配合物催化烯烃与CO的共聚反应和锆二世催化剂催化硅烷的脱氢聚合反应。在烯烃和炔烃的硼化反应中，Pd(0)和Pt(0)对不同的B-X键的反应性差异很大，本文将对差异的原因进行研究。在对映选择性氢甲酰化过程中，采用IMOMM方法研究不同膦配体的不同选择性，为设计更好的配体提供线索。通过本研究获得的反应中间体和过渡态的结构、光谱性质和能量等知识是对实验所得知识的补充，不仅有助于促进对过渡金属配合物复杂化学反应的基本认识，而且有助于新催化剂的逻辑设计，更好地控制复杂的化学反应。在整个拟议的研究过程中，将保持与实验组的密切联系。

The Theoretical and Computational Chemistry Program is supporting Prof. Keiji Morokuma at Emory University in his theoretical research on transition metals and their complexes. High level ab initio theoretical calculations are applied to a wide range of problems on structure and reactions of transition metal atoms, ions, complexes and clusters. The potential energy surfaces of a variety of chemical reactions will be calculated, ranging from gas phase reactions of bare transition metal ions and atoms and simple complexes, activation of various bonds by complicated transition metal complexes, the potential energy profiles of full catalytic cycles by organometallic catalysts, and reactions of transition metal clusters and cluster complexes. In addition to the standard ab initio molecular orbital (MO) methods, the Integrated Molecular Orbital + Molecular Mechanics (IMOMM) method and the integrated MO + MO (IMOMO) method, developed recently by the principle investigator, will be used for studies of reactions involving complicated ligands. Theoretical studies of full catalytic cycles by transition metal complexes, which still remain a challenge to theoreticians, will be performed for (1) boration of alkenes and alkynes by Pt(0) and Pd(0) complexes, (2) regio- and enantio-selective hydroformylation of olefins by Rh(I) catalyst with a chiral ligand BINAPHOS, and (3) Murai's C-H activation of aromatic ketones by Ru complexes. In addition copolymerization of olefin and CO catalyzed by Pd(II) complex and dehydrogenative polymerization of silanes by zirconocene catalysts will be studied. In the boration of alkenes and alkynes, Pd(0) and Pt(0) have very different reactivities to different B-X bonds, and the origin of the difference will be studied. In enantioselective hydroformylation, the different selectivity with different phosphine ligands will be studied with the IMOMM method to provide a clue for design of better ligands. The knowledge to be obtained through this research, such as structure, spectroscopic properties and energies of reaction intermediates and transition states, is complementary to that gained from experiments, and is expected not only to promote the fundamental understanding of complicated chemical reactions of transition metal complexes but also to help logical design of new catalysts for better control of complicated chemical reactions. Close contact with experimental groups will be maintained throughout the proposed research.