Absolute rate expressions for the abstraction of hydrogen by primary, secondary, and tertiary alkyl radicals from thiophenol
作者:James A. Franz、Bruce A. Bushaw、Mikhail S. Alnajjar
DOI:10.1021/ja00183a040
日期:1989.1
= 2.303RT kcal/mol; isopropyl, log (k/Msup minus}1} ssup minus}1}) = (9.26 plus minus} 0.19) - (1.70 plus minus} 0.21)/theta}; tert-butyl, log (k/Msup minus}1} ssup minus}1}) = (9.26 plus minus} 0.26) - (1.50 plus minus} 0.20)/theta}. Rate constants at 298 K vary from 0.8 times} 10sup 8} to 1.5 times} 10sup 8} Msup minus}1} ssup minus}1} for the hydrogen-transfer reactions. 32
用动力学吸收光谱 (KAS) 确定叔丁基、异丙基、正丁基和正辛基自由基从壬烷中的苯硫酚中提取氢的绝对速率表达式。烷基自由基是通过二烷基二硫化物的光解或二叔丁基过氧化物和三烷基膦在苯硫酚存在下的光解产生的。从 225 到 355 K,膦法中烷基的铼表达式如下:正丁基,log (k/Msup minus}1} ssup minus}1}) = (9.40 plus minus} 0.13) - (1.74 加减} 0.21)/theta}, theta} = 2.303RT kcal/mol; 异丙基,log (k/Msup minus}1} ssup minus}1}) = (9.26 plus minus} 0.19) - (1.70 plus minus} 0.21)/theta};叔丁基,log (k/Msup minus}1} ssup minus}1})