has been used for the first time to obtain accurate measurements of rate constants of some bimolecular, second-order cycloaddition reactions. As a test of the potential use of this technique for the study of second-order reactions, the rate constants and the activation parameters for the cyclodimerization reactions of chlorotrifluoroethylene (CTFE) and tetrafluoroethylene (TFE) were determined in the
气相核磁共振动力学技术首次用于精确测量一些双分子二级环加成反应的速率常数。为了测试该技术在二级反应研究中的潜在用途,在 240-340 度的温度范围内确定了
三氟氯乙烯 (C
TFE) 和
四氟乙烯 (
TFE) 环二聚反应的速率常数和活化参数C,使用商业高温核磁共振探头。结果与公布的数据非常吻合,然后将该技术应用于 1,1-二
氟丙二烯与
1,3-丁二烯的反应,其结果表明,当试剂数量很少且同时存在多个竞争过程时,将气相 NMR 用于反应动力学特别有价值。在该反应中观察到的主要过程是区域选择性 [2+2] 和 [2+4] 环加成,其速率和活化参数已确定 [k2 = 9.3 x 10(6) exp(-20.1 kcal x mol(-1)/ RT) L/mol(-1) xs(-1) 和 k3 = 1.2 x 10(6) exp(-18.4 kcal x mol(-1)/RT) L/mol(-1) xs(-)(1