浅析质谱中的广义麦式重排

Analysis of General McLafferty Rearrangement in Mass Spectrometry

麦氏重排是对质谱分析中分子离子的重排反应提出的经验规则。对经典麦式重排的概念、裂解过程及其应用做进一步拓展,形成了广义麦式重排。在广义麦式重排中,γ-H的经典麦式重排是一步完成的六元环协同裂解,分子离子亦可通过六元环或五元环过渡态进行协同重排裂解,发生相应的γ-R、β-H(或R)的迁移,产生不同的碎片离子。这种广义麦氏重排在各种常见官能团化合物中均可发生,其在质谱解析和化合物结构研究中具有广泛应用。

Mc Lafferty rearrangement is an empirical rule proposed for the rearrangement of molecular ions in mass spectrometry. Further expanding the concept, cleaving process and application of classic McLafferty rearrangement,the general Mc Lafferty rearrangement is formed. In the general Mc Lafferty rearrangement, the γ-H transference of six-membered ring cooperatively completes in one step. The cooperative rearrangement of molecular ions can also occur through a six-membered or five-membered ring transition state and the γ-R or β-H(R) of molecular ions accomplishes the transference, which results in different fragment ions. This general McLafferty rearrangement can occur in various compounds with most functional group, which is helpful in mass spectrometry analysis and compound structure research and extend the breadth of the applications.