Theory for Control of Selectivities in Reactions and Visualization of Organometallic Reactions

我们学习了以下科目。对硅化合物的高反应性进行了理论研究。用从头计算的方法阐明了五配位硅与H^-和F^-的配体取代反应机理。通过在势能面上定位六配位过渡态，讨论了反应的选择性。用轨道相互作用的方法阐明了硅化合物和碳化合物在反应性和化学键上的差别。应用对轨道相互作用方案研究了过渡金属与碳团簇C_<60>的相互作用。这种相互作用已被证明是非常局部的，与烯烃的过渡金属配合物非常相似。实验研究了三乙胺对碲氧化物去除的影响，并提出了其作用机理。对Sharpless试剂的不对称环氧化反应进行了理论研究。对硒氧化物消去的理论计算澄清了反应中选择性的来源。在电子离域的基础上，提出了一个新的轨道概念。化学反应的多样性和相似性已被证明与前沿轨道理论有关。提出了局部电负性和硬度的新概念。

We have studied the following subjects.1. The high reactivity of silicon compounds has been studied theoretically. The mechanism of ligand substitution reactions of pentacoordinated silicon species with H^- and with F^- has been clarified by means of ab initio MO calculations. The selectivity in the reaction has been discussed by locating hexacoordinated transition states on the potential energy surfaces. The difference in reactivities and chemical bondings between silicon compounds and carbon compounds has been clarified by means of orbital interactions.2. The interaction between transition metals and carbon cluster C_<60> has been investigated by applying paired orbital interaction scheme. The interaction has been shown to be very local, bearing a close resemblance to the transition-metal complexes of alkenes.3. The effect of triethylamine on the telluroxide elimination has been investigated experimentally and its mechanism has been suggested.4. Asymmetric epoxidation by Sharpless reagent has been studied theoretically.5. Theoretical calculations on selenoxide elimination have clarified the origin of selectivities in the reaction.6. A new orbital concept has been derived on the basis of electron delocalization. Multifariousness and likeness of chemical reactions have been shown to be connected with the frontier orbital theory. Novel concepts of local electronegativity and hardness have been proposed.