作者:Charles Brown、B. Terence Grayson、Robert F. Hudson
DOI:10.1039/p29790000427
日期:——
The free energies of Z–E isomerisation of a wide range of symmetrical N-sulphenylimines have been measured at the coalescence temperature by a 1H n.m.r. procedure. In two cases the rate of isomerisation of unsymmetrical N-sulphenylimines at a series of temperatures has been measured and activation enthalpies and entropies determined. The effect of substituents on the isomerisation barrier ΔG* has been
已通过1 H nmr程序在聚结温度下测量了各种对称N-磺基苯亚胺的Z - E异构化的自由能。在两种情况下,已经测量了在一系列温度下非对称N-磺苯基亚胺的异构化速率,并确定了活化焓和熵。取代基对异构化势垒ΔG的影响*可以通过氮孤对与亚胺碳和氮上取代基的超共轭转化来解释,该取代以线性转变态用于转化过程。使用扩展的Hückel扰动方法以轨道方式讨论了结果,该方法可用于定性地解释取代基对广泛的亚氨基化合物(包括胍和亚氨基碳酸酯)的反转势垒的影响。