Theoretical Study of Flexible Molecular Systems Possessing Complexed Electronic Structure tOWARDS Reaction Design and Control

本项目利用现代电子结构理论对具有柔性电子结构的过渡金属络合物进行了理论研究，用密度泛函理论和后Hartree-Fock方法研究了σ-键与镍(0)络合物的氧化加成反应。虽然密度泛函理论不能定量描述反应的正确特征，但在采用高质量基组的情况下，高精度的后Hartree-Fock方法给出了正确的结果。为了进行真实络合物的后Hartree-Fock计算，我们新提出了可以考虑大体积取代基电子效应的移位算符。由于多核过渡金属络合物是理论化学中极具挑战性的研究课题，我们从理论上对其电子结构和…进行了理论研究几个双核和三核配合物的成键性质更强。例如，Re双核配合物要求我们使用多参考电子结构理论。这些Re双核配合物具有金属-金属键，其键级比形式值小得多。光致自旋捕获配合物因其潜在的分子器件能力而成为近年来感兴趣的材料之一。我们从理论上研究了铁(III)络合物的光致自旋捕获特性。有趣的是，与通常的理解相反，中间自旋态的势能面与低自旋态和高自旋态的势能面相当接近。这一新的结果引起了实验界的极大兴趣。过渡金属络合物催化反应在理论化学中是非常有趣的，因为这种催化剂通常是有用的和复杂的。本文从理论上研究了Ir催化苯的直接硅基化反应。我们的理论研究清楚地表明，活性物种是Ir(V)络合物，催化反应通过Ir(III)和Ir(V)物种进行。较少

Theoretical studies of transition metal complexes bearing flexible electronic structure were carried out with modern electronic structure theories in this project.Oxidative addition of σ-bond to nickel(0) complex was theoretically investigated with density functional theory and post-Hartree-Fock method. Though the density functional theory did not present quantitatively correct features of the reaction, highly sophisticated post-Hartree-Fock method presented correct results when high quality basis sets were employed.To perform post-Hartree-Fock calculation of real complexes, we newly proposed shift operator with which we can incorporate electronic effects of bulky substituent. This shift operator is very effective ; actually, we succeeded to reproduce the electronic structure of large metal complexes with this shift operator.Because multinuclear transition metal complexes are challenging research subjects of theoretical chemistry, we theoretically investigated electronic structure and … More bonding nature of several dinuclear and trinuclear complexes. For instance, rhenium dinuclear complexes requested us to use multi-reference electronic structure theory. Those rhenium dinuclear complexes have metal-metal bond, bond order of which is much smaller than the formal value.Light-induced spin-trapping complex is one of interesting materials, recently, because of their potential abilities for molecular devices. We theoretically investigated light-induced spin trapping feature of iron(III) complex. Interestingly, the potential energy surface of the intermediate spin state is rather close to those of the low spin and high spin states, against the general understanding. This new result attracts a lot of interests from the experimental field.Catalytic reaction by transition metal complexes is very interesting in theoretical chemistry, because such catalyses are useful and complicated in general. Here, iridium-catalyzed direct silylation of benzene was theoretically investigated. Our theoretical study clearly shows that active species is iridium(V) complex and the catalytic reaction takes place through iridium(III) and iridium(V) species. Less