Studies in trifluoromethanesulfonic acid. 2. Kinetics and mechanism of isomerization of xylenes
Studies in trifluoromethanesulfonic acid. 2. Kinetics and mechanism of isomerization of xylenes
复制标题
三氟甲磺酸的研究。
DOI：
10.1002/chin.198314091
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
R. Roberts
中科院分区：
文献类型：
--
作者：
R. Roberts
用核磁共振、气相色谱和电导法测定了邻二甲苯和对二甲苯在三氟甲磺酸(CFgSOgH)溶剂中异构化为间二甲苯的速率。在低浓度(0.02M)下，反应符合预期的一级反应动力学，而在较高浓度下，反应遵循表观二级动力学。从质子化和非质子化溶质分子之间的紧密离子配对和可能的给体-受体络合物侵入的角度讨论了该反应的机理。
The rates of isomerization of o-and p-xylenes to m-xylene have been measured in the solvent trifluoro-methanesulfonic acid (triflic acid, CFgSOgH), using NMR, GLC, and conductimetric methods. At low concentration (< 0.02 M) theexpected first-order kinetics were observed, whereas at higher concentrations the reactions followed apparent second-order kinetics. The mechanism of the reaction is discussed in terms of intimate ion pairing and possible incursionof donor-acceptor complexes between protonated and unprotonated solute molecules.