超临界条件下离子液体催化苯与丙烯烷基化的反应机理研究

用FT-IR和¹H NMR分析KOH无水乙醇溶液滴定前后的盐酸三乙胺无水乙醇溶液, 发现(C₂H₅)₃NHCl中的H具有显著的质子酸性, 且在滴定过程中有KCl生成, 滴定后的¹H NMR谱中δ 7.3处的谱峰完全消失. 将合成的(C₂H₅)₃NHCl/AlCl₃离子液体脱水, 在超临界条件下催化全氘代苯与丙烯的烷基化. 用同位素取代法, 研究了反应机理. 结果表明, 脱水后的离子液体仍然可以催化烷基化反应, 液体产物的GC-MS分析结果支持正碳离子机理. 对比反应前后离子液体的¹H NMR谱图发现, 反应后离子液体中盐酸三乙胺中与N相连H的谱峰强度较反应前降低了80.12%, 可能是引发反应消耗了这部分H.

Alkylation Mechanism of Benzene with Propylene Catalyzed by Ionic Liquid under Super Critical Conditions

It was proved that the H in (C₂H₅)₃NHCl was proton acidic through the FT-IR and ¹H NMR analysis of (C₂H₅)₃NHCl solution titrated with KOH alcohol solution, during which KCl was formed and after which the signal of H at δ 7.3 in the ¹H NMR spectrum disappeared completely. When the dewatered (C₂H₅)₃NHCl/AlCl₃ ionic liquid was used as a catalyst, the alkylation catalytic mechanism under a super critical conditions was studied using an isotope exchange method in this paper. The results showed that the dewatered ionic liquid could still catalyze the alkylation, and the carbonium mechanism was established through the GC-MS analysis of the reaction liquid product. It was found that the strength of H linked to N was reduced by 80.12% comparing the ¹H NMR spectrum before and after the reaction, so the H^＋ initiating the reaction was the H linked to N in the (C₂H₅)₃NHCl.