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

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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.