一类2(1H)-喹喔啉化合物的裂解机理

Fragmentation Mechanism for A Group of 2(1H)-Quinoxalines

用电子轰击质谱(EI_MS)研究了一类喹喔啉化合物 :1_烷基_3_甲基_2(1H)_喹喔啉_2_酮(1_alkyl_3_methyl_2(1H)_quinoxalin_2_one,简称AMQ ,其中alkyl=H,CH3,C2H5,n_C3H7,n_C5H11,n_C16H33) ;结果表明随着烷基链的增长 ,样品熔点通常会有所降低 ,结合在电子轰击下所产生的裂解碎片离子 ,并根据其结构特征以乙基化样品为代表 。

A group of 2(1H) - quinoxalin - 2 - ones: 1 - alkyl - 3 - methyl - 2(1H) - quinoxalin - 2 - one(AMQ, alkyl=H, CH3, C2H5, n - C3H7, n - C5H11, n - C16H33)has been researched by electron impact mass spectrometry(EI - MS). The effects of different substituting alkyls on melting point were evaluated. Results show that as the length of the alkyl chain at the nitrogen on the 1 - position increases, the melting point of the compounds usually decreases. Based on the analysis of fragments appeared in EI mass spectrum, as well as the structure feature of these compounds, the fragmentation mechanism of 1 - ethyl - 3 - methyl - 2(1H) - quinoxalin - 2 - one, as an example, was proposed.