The geometries of cis-and trans-bis(1,4-trimethylsilyl)-1,2,3,4,5,6-hexamethyl-1,4-disilacyclohexa-2,5-diene have been studied by 13C NMR and X-ray single crystal analysis. The trans isomer adopts a nearly planar conformation with a slight deformation toward a chair form which is most likely caused by steric interactions between the vinyl-methyl substituents and the groups on the ring silicon atoms
通过13 C NMR研究了顺式和反式双(1,4-三甲基甲
硅烷基)-1,2,3,4,5,6-六甲基-1,4-二
硅环己基-2,5-二烯的几何结构和X射线单晶分析。所述反式异构体与采用朝着最有可能是在环
硅原子
乙烯基-甲基取代基和基团之间的空间相互作用引起的椅子形式的轻微变形几乎平坦的构象。与反式异构体和其他先前报道的二
硅环
己二烯不同,顺式异构体存在于略微扭曲的船形结构中。两个庞大的三甲基甲
硅烷基取代基位于假轴位。该发现与最近的计算相符,后者预测大的1,4取代基应在环己2,5-二烯基环系统中占据轴向位置。