Following the principle of sustainable and green development, the environmentally friendly and highly efficient manufacturing of fluorine chemical products is becoming an unavoidable development trajectory. Ionic liquid catalysts have shown great potential to replace traditional metal salt catalysts, which cause environmental pollution, in the dimerization of perfluorinated olefins. In this study, a series of strong nucleophilic thiocyanate ionic liquids with various cationic structures were designed and synthesized. The catalytic activity of 4-dimethylaminopyridine (DMAP) ionic liquids exceeded that of reported catalysts, being 2.4 times higher than that of traditional metal salt catalysts, and 1.5 times higher than that of imidazole ionic liquids reported in the literature. Under the optimal reaction conditions, the high turnover frequency (TOF) value of the [C₆DMAP][SCN] catalyst performance reaches 325.04 h⁻¹. Based on the experimental results, density functional theory (DFT) and XPS analysis, the excellent catalytic performance of [C₆DMAP][SCN] can be attributed to the dual active sites of anions and cations, and a dual-activation reaction mechanism is further proposed. This study not only expands the application of ionic liquid in the hexafluoropropylene dimerization reaction but also helps establish a more efficient, green, and sustainable catalytic process for hexafluoropropylene dimerization.

中文翻译：

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强亲核双功能离子液体催化全氟烯烃高效二聚

遵循可持续、绿色发展原则，氟化工产品的环保高效制造正在成为必然的发展轨迹。离子液体催化剂在全氟烯烃二聚反应中显示出替代传统金属盐催化剂的巨大潜力，而传统金属盐催化剂会造成环境污染。本研究设计并合成了一系列具有多种阳离子结构的强亲核硫氰酸盐离子液体。 4-二甲氨基吡啶（DMAP）离子液体的催化活性超过了已报道的催化剂，比传统金属盐催化剂高2.4倍，比文献报道的咪唑离子液体高1.5倍。在最佳反应条件下，[C ₆ DMAP][SCN]催化剂性能的高转换频率（TOF）值达到325.04 h ^-1。基于实验结果、密度泛函理论（DFT）和XPS分析，[C ₆ DMAP][SCN]优异的催化性能可归因于阴离子和阳离子的双重活性位点，双活化反应机理为进一步提出。该研究不仅拓展了离子液体在六氟丙烯二聚反应中的应用，而且有助于建立更高效、绿色、可持续的六氟丙烯二聚催化工艺。