摘要
温和条件常温常压下 ,苯胺与CS2 在AlCl3 催化作用下反应 ,对反应混合物用乙醇进行重结晶获得白色片状晶体 ,GC/MS分析表明该晶体为异硫氰酸苯酯。然而 ,用熔点测定、HPLC/MS/MS ,FTIR ,UV和1HNMR等手段对此晶体进行分析 ,确定其为二苯硫脲。结合GC/FTIR谱图 ,研究了二苯硫脲的质谱裂解机理。实验结果表明二苯硫脲质谱裂解中可能发生了中性丢失 ,丢失了中性分子苯胺 ,生成的异硫氰酸苯酯分子离子由于π电子共轭而致稳。此机理同样能合理解释二苯脲和二萘硫脲的GC/MS谱图中只出现异氰酸苯酯和异硫氰酸萘酯分子离子峰的现象。
With the catalyst of AlCl3, aniline reacted with CS2 under the mild conditions of room temperature and ambient atmosphere. Recrystallzing the reaction mixture with ethanol gave white, flake-like pure crystal, which is phenyl iso-thiocyanate determined by GC/MS spectrum. However, identified by melting point, FPLC/MS/MS, FTIR, UV and H-1 NMR analyses, the pure crystal should be diphenyl thiourea. Associated with GC/FTIR spectrum, the mechanism of mass cleavage of diphenyl thiourea was studied. The results showed that neutral molecule of aniline may be lost in the cleavage of mass spectra, while the remainder molecular ion of phenyl iso-thiocyanate became steady due to the conjugate of pi electron. This mechanism can also reasonably explain the fact that only molecular ionic peak of phenyl iso-thiocyanate and naphthyl iso-thiocyanate was presented in the GC/MS spectra of diphenylurea and diphenyl thiourea.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2003年第4期816-819,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金 (2 0 2 0 70 0 3)
江苏大学高级人才基金 (No 681 0 0 0 0 0 1 9)资助
