Benzidine rearrangements. 16. The use of heavy-atom kinetic isotope effects in solving the mechanism of the acid-catalyzed rearrangement of hydrazobenzene. The concerted pathway to benzidine and the nonconcerted pathway to diphenyline
作者:Henry J. Shine、Henryk Zmuda、Koon Ha Park、Harold Kwart、Ann Gaffney Horgan、Martin Brechbiel
DOI:10.1021/ja00373a028
日期:1982.5
Kinetic isoptope effects (KIE) in the acid-catalyzed rearrangement of hydrazobenzene to benzidine and diphenyline have been measured. Nitrogen KIE were determined by whole-molecule mass spectrometry on each of the products obtained at low and 100% conversions from mixtures of hydrazobenzene and (/sup 13/N,/sup 15/N') hydrazobenzene. The results were k(/sup 14/N)/k(/sup 15/N) = 1.0222 for benzidine
已经测量了酸催化重排偶氮苯为联苯胺和二苯胺中的动力学同位素效应 (KIE)。氮 KIE 通过全分子质谱法对以低转化率和 100% 转化率从偶氮苯和 (/sup 13/N,/sup 15/N') 偶氮苯的混合物中获得的每种产物进行测定。结果是联苯胺的 k(/sup 14/N)/k(/sup 15/N) = 1.0222 和联苯胺的 1.0633。使用 /sup 14/C 和 /sup 13/C 标记测定碳 KIE,前者使用计数技术,后者使用全分子质谱法。再次对与低转化率和 100% 转化率隔离的两种产品进行测量。使用重氮苯和 (4-/sup 14/C) 重氮苯的混合物得到 k(/sup 12/C)/k(/sup 14/C) = 1.0284 联苯胺和 1.0011 联苯胺。使用重氮苯和(4,4'-/sup 13/C/sub 2/)重氮苯的混合物得到k(/sup 12/C)/k(/sup 13/C)