Coordination Chemsitry and Theoretical/Computational Studies

This review article reports several theoretical/computational approaches to coordination chemistry. First, spin state and M-M multiple bonding of dinuclear and trinuclear transition metal complexes are discussed on the basis of electronic structures obtained by multi-reference wave-function theory. In a cuboctahedral Pd13 cluster complex, theoretical knowledge obtained by DFT calculations is presented on determining factor(s) of its highly symmetrical structure. In theoretical studies of catalysis which is one of important functions of transition metal complexes, discussion is presented on how to understand key intermediates, transition states, and reaction mechanisms from the viewpoint of ligand field theory. Transition metal complexes in crystal exhibit interesting properties different from those in solution. Isomerization reaction and emission spectrum of transition metal complexes in crystal are discussed using theoretical calculations incorporating crystal effects. Gas adsorption to flexible porous-coordinationpolymers (PCPs) is investigated using a computational method consisting of DFT calculations of infinite system and post Hartree-Fock ones of cluster model. This computational approach succeeded in elucidating the origin of gate-opening gas adsorption mechanism and unusual sigmoidal adsorption isotherm.