Quantum-Chemically Guided Insights on Ionic Liquid Catalysts for Biobased Polycarbonate Synthesis─Mechanistic Exploration and Cation-Functionalized Optimization

作者：Hao Wang, Xintong Zhang, Zhencai Zhang, Yiwen Zhang, Yang Zhao, Wentao Zhang, Chunshan Li, Fei Xu · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.4c10922 · 被引用次数：2 · 研究领域：Ionic liquids properties and applications、Catalysis for Biomass Conversion、Chemistry and Chemical Engineering

The advancement of biobased polymers is intrinsically linked to the optimization of polymerization catalyst design. This necessitates a comprehensive understanding of the structure–effect relationship and the control mechanisms inherent in these catalysts. Recent studies have demonstrated the potential of ionic liquid (IL) catalysts to activate glucose-derived diol isosorbide (ISB), which could overcome the challenge of low and imbalanced hydroxyl activity of ISB. However, the microscopic mechanism of IL-catalyzed melt polycondensation remains elusive, lacking a well-established foundation for the rational design of IL catalysts. Using the melt polycondensation of ISB as a model, this study combines computational and experimental investigations to reveal that IL-catalyzed melt polycondensation follows an addition–elimination mechanism. ILs can alter the mechanistic pathway by forming tetrahedral intermediates, thereby reducing the energy barrier for both the exo - and endo -OH routes. Additionally, cationic functionalization can significantly regulate the electrophilicity and nucleophilicity of ILs, as well as stabilize transition states by C–H bonds and π electrons in the cationic ring. The optimal catalyst 1-ethyl-2-methylpyridinium bromide ([1-C 2 -2-C 1 Py]Br) achieves the product with M w of 133.9 kg/mol, which is due to the modification of cations by a weak electron-donating group enhancing π···π weak interactions. This research contributes a theoretical foundation for ...