Synthesis and Characterization of Unstable Organic Molecules Using Photochemical Process at Low Temperature

点击翻译按钮获取中文摘要

This research is undertaken in order to design and generate unstable organic molecules by utilizing mainly matrix isolation techniques. Investigators involved in the project have been selected from the following four major fields of physical organic chemistry so as to attack the target molecules of mutual interests from multilateral standpoints. The results obtained in each research fields are summarized :(1) Design and Synthesis of Precursor for Generating Unstable Organic Molecules - Several new precursors generating oxonium ylide, oxirenium, thirenium, and azirinium ions are designed and synthesized and are shown to be not only very attractive in reactive intermediate chemistry but also useful on synthetic viewpoints.(2) Product Analysis of the Reactions Involving Unstable Molecules - Reactions involving radicals, 1,4-diradicals, and 1,4-radical cations are investigated not only in organic solvent but also in the solid state and many useful information concerning the reaction mechan … More ism and biological meanings is obtained.(3) Spectroscopic Detection and Characterization of Unstable Organic Molecules - Unstable molecules such as carbenes, nitrenes, silylenes, benzotropone, carbonyl oxides, carbonyl ylides are detected and characterized by matrix isolation techniques. Magnetic interaction of polycarbenes and polynitrenes are revealed. Oxidation reactions within matrix containing oxidants such as O_2 and NO_2 are analyzed and mechanisms including reactive intermediates are proposed. Conformational isomers which are convertible under IR irradiation within matrix are analyzed and the mechanisms for the isomerization are suggested.(4) New theoretical methods to evaluate the effect of steric repulsion on the electronic structure of unstable molecules are proposed. The stabilities of the reactive molecules such as those involved in the reaction of sililenes and O_2 and three membered cyclic compounds consisting of Si, Ge, Sn and Pb are evaluated by theoretical calculation.These new find are discussed comprehensively in the joint meetings including participants outside of the group and new "challenging" molecules to be attacked are suggested. Less