摘要
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_(12)H_8]^(2+)、[C_(12)H_6]^(2+)、[C_(10)H_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,而样品离子流占总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 of doubly charged ion mass spectra (2E spectra), the substituents effect and the target gas pressure deppendence of biphenyl derivitives was presented in this work. The decomposition of doubly charged ion formed in the ion source is dominant by the losses of H, C_2H_2, C_2H_4 and HR(Rrepresents substituent). [C_(12)H_8]^(2+), [C_(12)H_6]^(2+) and [C_(10)H_6]^(2+) among others are the most stable product ions. The substiuents effect is Various in different decomposition reactions, and in some cases it can not be predicted by Hammett equition. While the TIC of 2E spectra was markedly influenced by the target gas pressure, but the fragmentation pattern of the 2E spectra is independent of it.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1992年第2期180-185,共6页
Acta Chimica Sinica
基金
国家自然科学基金
