Nukazawa Takumi, Iwamoto Takeaki
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Dalton Trans. 2020 Dec 8;49(46):16728-16735. doi: 10.1039/d0dt03408h.
Heavy element analogues of bicyclo[1.1.0]butane have attracted much attention as they often exhibit skeletal isomerisations that are not observed for all-carbon bicyclo[1.1.0]butanes. The reaction of a bicyclo[1.1.0]tetrasil-1(3)-ene with CCl4 at low temperature provided orange crystals of a 1,3-dichlorobicyclo[1.1.0]tetrasilane containing a planar Si4 ring with a π-type bridgehead Si-Si bond. The equilibrium between the bicyclotetrasilane and an isomer, 1-chloro-2-(chlorosilyl)cyclotrisilene in solution, which is an unprecedented interconversion mode of Si4R6 isomers, was identified by NMR spectroscopy and also the formation of its 4-(dimethylamino)pyridine (DMAP) complex.
双环[1.1.0]丁烷的重元素类似物备受关注，因为它们常常表现出一些全碳双环[1.1.0]丁烷未观察到的骨架异构化现象。双环[1.1.0]四硅-1(3)-烯在低温下与CCl₄反应，生成了一种1,3 - 二氯双环[1.1.0]四硅烷的橙色晶体，该晶体含有一个平面Si₄环以及一个π型桥头Si - Si键。通过核磁共振光谱法确定了双环四硅烷与一种异构体（溶液中的1 - 氯 - 2 -（氯硅基）环三硅烯）之间的平衡，这是一种前所未有的Si₄R₆异构体的相互转化模式，同时还确定了其4 -（二甲基氨基）吡啶（DMAP）配合物的形成。
