New Coordination Complexes Based on the 2,6-bis[1-(Phenylimino)ethyl] Pyridine Ligand: Effective Catalysts for the Synthesis of Propylene Carbonates from Carbon Dioxide and Epoxides

• Published in: Molecules (Basel, Switzerland) Switzerland), 2018-09, Vol.23 (9), p.2304
• Main Authors: Xia, Li, Wang, Wen-Zhen, Liu, Shuang, Jia, Xin-Gang, Zhang, Ying-Hui, Li, Lei-Lei, Wu, Ya, Su, Bi-Yun, Geng, Shu-Bo, Fan, Wei
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Carbon Dioxide - chemistry; Carbonates; Catalysis; catalyst for propylene carbonate; Catalysts; Chloride; Chlorine; coordination complexes; Coordination Complexes - chemistry; Crystallography, X-Ray; Cycloaddition Reaction; DFT calculations; Distortion; Epoxides; Epoxy Compounds - chemistry; Event-related potentials; Ligands; Molecular Conformation; Nitrogen; Printing industry; Propane - analogs & derivatives; Propane - chemical synthesis; Propane - chemistry; Propylene; Pyridines; Pyridines - chemistry; Static Electricity
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules23092304

We aimed to develop new effective catalysts for the synthesis of propylene carbonate from propylene oxide and carbon dioxide. A kind of M Cl coordination complex was fabricated based on the chelating tridentate ligand 2,6-bis[1-(phenylimino)ethyl] pyridine ( ). The obtained products were characterized by elemental analysis, infrared spectroscopy, ultraviolet spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. It was found that the catalytic activity of the complexes with different metal ions, the same ligand differed and co-catalyst, where the order of greatest to least catalytic activity was > > . The catalytic system composed of complex and DMAP proved to have the better catalytic performance. The yields for complex systems was 86.7% under the reaction conditions of 100 °C, 2.5 MPa, and 4 h. The TOF was 1026 h ¹ under the reaction conditions of 200 °C, 2.5 MPa, and 1 h. We also explored the influence of time, pressure, temperature, and reaction substrate concentration on the catalytic reactions. A hypothetical catalytic reaction mechanism is proposed based on density functional theory (DFT) calculations and the catalytic reaction results.