Taira Kanako, Ichinohe Masaaki, Sekiguchi Akira
Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba (Japan), Fax: (+81) 298534314.
Chemistry. 2014 Jul 21;20(30):9342-8. doi: 10.1002/chem.201402482. Epub 2014 Jun 6.
Isolable aryl-substituted silyl radicals (tBu2 MeSi)2(Ar)Si(·) (Ar = C6H5, 4-tBuC6H4, 4-PhC6H4, 3,5-tBu2C6H3) were synthesized by the reaction of the corresponding iodosilane with an equimolar amount of potassium graphite (KC8 ) in tetrahydrofuran (THF). The crystal structure of 3,5-tBu2C6H3 derivative, which was determined by X-ray crystallography, showed a planar geometry around the Si atom for the radical center. EPR studies of all four radicals revealed the lack of the delocalization of the unpaired electron over the aromatic ring. Reactivity and spectroscopic studies of the less-hindered phenyl-substituted silyl radical showed that it exists as an equilibrium mixture of the radical and its silene-type dimer in solution.
通过相应的碘硅烷与等摩尔量的石墨钾（KC8）在四氢呋喃（THF）中反应，合成了可分离的芳基取代甲硅烷基自由基（tBu2MeSi）2（Ar）Si(·)（Ar = C6H5、4-tBuC6H4、4-PhC6H4、3,5-tBu2C6H3）。通过X射线晶体学确定的3,5-tBu2C6H3衍生物的晶体结构表明，自由基中心的Si原子周围具有平面几何结构。对所有四种自由基的电子顺磁共振（EPR）研究表明，未成对电子在芳环上没有离域。对空间位阻较小的苯基取代甲硅烷基自由基的反应性和光谱研究表明，它在溶液中以自由基及其硅烯型二聚体的平衡混合物形式存在。
