Analysis of spectral parameters of trans- and cis-silyl substituted 1,2-dihalogenoethenes including one-bond CC spinspin coupling constants across double bonds
作者:K. Kamieńska-Trela、L. Kania、J. Sitkowski、E. Bednarek
DOI:10.1016/0022-328x(89)85328-8
日期:1989.3
allows ready assignment of the configuration. The one-bond spinspin coupling constants between the ethylenic carbons depend on the electronegativities of the substituents, trans1J(CC) in most cases being larger than1J(CC)cis.
一些反式-和顺式-1-三烷基甲硅烷基-1,2- dihalogenoethenes已被合成和它们的13 C和1 1 H NMR光谱记录下来。研究的化合物易于进行可逆的顺式-反式异构化,顺式异构体在热力学上比反式异构体稳定。的值3 Ĵ(SiHα)反式是大约两倍那样大的3 Ĵ硅烷(SiH α)顺式,和的值2 Ĵ(C β ħ α)反式是大约十分之一的2 Ĵ(C β ħ α)顺式并且这允许配置的准备分配。烯属碳之间的单键自旋旋偶联常数取决于取代基的电负性,在大多数情况下,反式1 J(CC)大于1 J(CC)顺式。