Synthesis and performance of piperidinium‐based ionic liquids as catalyst for alkylation of p‐xylene with 1‐hexadecene. (7th January 2021)

• Record Type: Journal Article
• Authors: Ge, Sujuan; Zhou, Yuming; Sheng, Xiaoli; Mao, Chunfeng; Zhao, Lina; Xu, Jianxing; Qiu, Lei
• Is Part Of: Applied organometallic chemistry. Volume 35:Number 4(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-07
• Subjects: alkylation -- piperidinium‐based ionic liquids -- reaction performance -- recyclability; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.6147
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : Piperidinium‐based ionic liquids (ILs) were synthesized under mild conditions by coordinating N ‐alkyl‐ N ‐methylpiperidinium bromide ([Pip1, x ]Br) with anhydrous AlCl3 . The weak basicity of N ‐methylpiperidine had little impact on downstream problems from proton impurities and catalyst poisoning. The results of Fourier transform infrared (FT‐IR), electrospray ionization mass spectrometry (ESI‐MS), and nuclear magnetic resonance ( 27 Al NMR) confirmed that the active components in [Pip1, x ]Br‐2AlCl3 ( χ = 0.67) were [Al3 Cl9 Br] − and [Al2 Cl6 Br] − . Besides, the reaction performance of [Pip1, 8 ]Br‐2AlCl3 under different conditions was carried out by single‐factor experiment and further confirmed by orthogonal experimental method. Among these reaction conditions, the optimal combination was the reaction temperature of 40°C, ILs/O molar ratio of 0.2:1, px/O molar ratio of 12:1, and the reaction time of 30 min. Furthermore, [Pip1, 8 ]Br‐2AlCl3 had excellent stability and can be recycled 14 times. It was the high‐efficiency catalytic activity and prominent recyclability that made continuous industrial production possible. Abstract : Piperidinium‐based ionic liquids were synthesized under mild conditions. [Pip1, 8 ]Br‐2AlCl3 exhibited excellent catalytic capacity as well as cycle stability. The mechanism for alkylation of p ‐xylene with 1‐hexadecene was proposed.