Gas-phase pyrolytic reactions. part 4.1 Arrhenius parameters and hammett σ0 constants in gas-phase eliminations of alkyl pyridyl,-furyl-,and thienylcarboxylate esters
作者:Nouria A. Al-Awadi、Rasha F. Al-Bashir、Osman M.E. ElDusouqui
DOI:10.1016/s0040-4020(01)88383-6
日期:1990.1
of the gas-phase pyrolytic reactions of seven isopropyl (hetero)arylcarboxylate esters were calculated for 600 K to be: 75.34 for benzoate, and 100.0, 70.46, 94.03, 65.58, 100.9 and 120.2 for 2-thienyl-, 3-thienyl-, 2-furyl, 3-furyl, 3-pyridyl- and 4-pyridylcarboxylate, respectively. The corresponding Hammett replacement σ0 substituent constants of the heterocyclic groups are: 0.53, -0.13, 0.42, -0
计算出600 K时,七个(杂)芳基羧酸异丙酯的气相热解反应的一级速率系数(10 5 K / s -1)为:苯甲酸酯为75.34,苯甲酸酯为100.0、70.46、94.03、65.58分别对于2-噻吩基-,3-噻吩基-,2-呋喃基,3-呋喃基,3-吡啶基-和4-吡啶基羧酸盐分别为100.9和120.2。相应的哈米特σ更换0的杂环基团的取代基常数是:0.53,-0.13,0.42,-0.26,分别为0.55和0.88。报告的σ Ø该常数与其他气相和溶液数据一致,并且在常规电子和结构效应方面都可以合理化。此外,描述了四种新的异丙基杂芳基羧酸酯的物理常数。