用示踪原子法研究卤素非同位素交换反应的动力学

A RADIOTRACER STUDY OF THE KINETICS OF THE NON ISOTOPIC HALOGEN EXCHANGE REACTIONS

摘要: 本文以正丁醇中卤离子(I~-或Br~-)与卤代烷烃(C_(16)H_(33)Br或C_(16)H_(33)I)的交换反应为例,首次采用示踪原子法研究卤素非同位素交换反应的动力学,并与同位素交换结果做了比较。发现反应符合S_N2机构。不同交换反应的速度有显著差异,次序为碘-碘交换>碘-溴交换>溴-碘交换>溴-溴交换。利用溶剂效应解释了这一次序。测得了这几种交换的若干动力学参数等。本文介绍的方法对于用示踪原子法定量探讨S_N2机构的有机化学反应具有普遍意义。
- 非同位素交换 /
- 动力学 /
- 示踪原子法 /
- ~(82)Br /
- ~(125)I /
- 卤代十六烷
Abstract: The present paper reports that the exchanges between iodide ions or bromide ions and cetyl iodide or cetyl bromide in n-butyl alcohol which are studied for the first time by radiotracer method follow a second-order kinetics (SN2 mechanisms). The corresponding kinetic and/or thermodynamic parameters are obtained. The rates of these exchanges are found to be as follows:I-for-I>I-for- Br>Br-for-I>Br-for-Brwhich in turn is explained in terms of solvent effects. The theoretical treatment and the experimentation reported may also be applicable to similar reactions.
- Non isotopic exchange /
- Kinetics /
- Radiotracer /
- ~(82)Br /
- ~(125)I /
- Cetyl halide.

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