Substituent effects in the mass spectra of some γ- and β-substituted methyl butyrates
作者:Ian Howe、Dudley H. Williams、David G. I. Kingston、Harvey P. Tannenbaum
DOI:10.1039/j29690000439
日期:——
Results are presented (relative ion abundances, I.P. and A.P. measurements) to illustrate substituent effects in the mass spectra of some γ- and β-substituted methyl butyrates. It is argued that (i)‘sub-decomposition energy’ ions and (ii) competition in the source with fast fragmentation processes are important factors influencing parent/daughter ion ratios, which are then rationalised in terms of the
给出结果(相对离子丰度,IP和AP测量)以说明某些γ-和β-取代的丁酸甲酯在质谱中的取代基效应。有人认为,(i)“亚分解能”离子和(ii)快速分裂过程中的离子源竞争是影响母/子离子比的重要因素,然后根据这两个因素的变化对其进行合理化处理。取代基。在某些情况下,还引起对过渡态活化能的取代基效应。根据相对AP和频率因子来解释不同能量下的母子比率的变化。讨论了从M +中消除MeOH和McLafferty重排的机理。