Quaternary Nitrogen Heterocycles. II. Kinetics of Reversible Pseudobase Formation from N-Methyl Heterocyclic Cations
Quaternary Nitrogen Heterocycles. II. Kinetics of Reversible Pseudobase Formation from N-Methyl Heterocyclic Cations
复制标题
季氮杂环。
DOI：
10.1139/v73-294
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发表时间：
1973
影响因子：
1.1
通讯作者：
W. Meathrel
中科院分区：
文献类型：
--
作者：
J. W. Bunting;W. Meathrel
研究了2-甲基-4-硝基异喹啉、10-甲基吖啶和10-甲基-9-苯吖啶离子形成和分解假碱的动力学。这些反应的pH值曲线表明，对于每一种离子，根据反应的pH值不同，假碱的形成可能涉及水分子或氢氧根离子对杂环阳离子的攻击。假碱分解成阳离子可以通过中性或质子化的假碱物种或它们的动力学等价物发生。报道了每个离子的平衡和动力学的温度依赖性，并测量了2-甲基-4-硝基异喹啉离子反应的氘同位素效应。根据观察到的活化参数和同位素效应，讨论了反应的可能机理，并与相关反应进行了比较。
The kinetics of the formation and decomposition of the pseudobases from the 2-methyl-4-nitroisoquinolinium, 10-methylacridinium, and 10-methyl-9-phenylacridinium ions have been studied. The pH–rate profiles of these reactions indicate that for each of these ions, pseudobase formation may kinetically involve either attack of a water molecule or of hydroxide ion on the heterocyclic cation depending upon the pH of the reaction. Pseudobase decomposition to the cation may occur through either the neutral or protonated pseudobase species or their kinetic equivalents. The temperature dependences of the equilibrium and kinetics are reported for each ion, and deuterium isotope effects for the reactions of the 2-methyl-4-nitroisoquinolinium ion have been measured. Possible mechanisms for the reactions are discussed on the basis of the observed activation parameters and isotope effects and are compared with related reactions.