联苯取代物的双电荷离子质谱(2E谱)研究

本文研究了联苯取代物双电荷离子2E谱及其取代基效应和靶气压力影响。离子源中产生的双电荷离子的解离反应主要有丢失H原子、C~2H~2、C~2H~4、HR(R为取代基)等反应通道。产物离子中C~1~2H~8]^2^+、C~1~2H~6]^2^+、C~1~0H~6]^2^+等具有相当的稳定性。取代基对不同的反应有不同的影响, 主要取决于产物离子的相对稳定性。取代基对分子离子的稳定性的贡献有以下顺序: NH~2>OH>Ph>F>H>Br>NO~2。升高靶气压力, 2E谱的总离子流迅速升高, 而样品离子流的百分数却直线降低。靶气压力影响样品的检测灵敏度, 但不影响离子的碎裂途径。

A study on 2E spectra of biphenyl derivatives

Substituent effect and target gas pressure dependence study of 4-RC6H4Ph (R = H, NO2, F, NH2, OH, Br, Ph) showed that the decomposition of double charged ion formed in the ion source is dominated by the loss of H, C2H2, C2H4, and HR (R = substituent). C12H8]2+, C12H6]2+, and C10H6]2+, among others, are the most stable product ions. The various substituent effects in different decomposition reactions cannot be predicted by Hammett equation. While the total ion current of the 2E spectra was markedly influenced by the target gas pressure, the fragmentation pattern was independent of it.