Tetrahedrane and Cyclobutadiene: Synthesis and Structure of Highly Strained Hydrocarbons

四面体烷是一种具有高应变C-C键的碳氢化合物。由于骨架高度应变，C-C sigma键轨道能级的增加导致sigma- π共轭。环丁二烯是四面体的价电子同分异构体之一，是一种在矩形平面四元环内具有四个pi电子的环状不饱和化合物。本文研究了硅基稳定取代四面体的合成、结构分析和性质。通过四面体的光化学异构化，制备了全氟芳基取代的环丁二烯衍生物作为气敏和湿敏红色固体。用光谱数据和x射线晶体学对第一芳基取代环丁二烯进行了表征。我们还开发了新的多功能取代四面体的合成路线，目前已报道了20多个稳定的衍生物。

Tetrahedrane is a hydrocarbon with highly strained C-C sigma bonds. Because of the extremely strained skeleton, the increase in the energy level of C-C sigma-bond orbitals results in the sigma-pi conjugation. Cyclobutadiene is one of valence isomers of tetrahedrane and a cyclic unsaturated compound with four pi-electrons within a rectangular planar four-membered ring.We have investigated the synthesis, structural analysis and properties of substituted tetrahedranes stabilized by silyl groups. The perfluoroaryl substituted cyclobutadiene derivatives were prepared as air- and moisture-sensitive red solids by the photochemical isomerization of the corresponding tetrahedranes. The first aryl substituted cyclobutadienes were characterized by spectroscopic data as well as by Xray crystallography. We also developed new versatile synthetic routes of substituted tetrahedranes, and reported more than 20 stable derivatives up to now.