Highly active Mn(III) meso-tetrakis(2,3-dichlorophenyl)porphyrin catalysts for the cycloaddition of CO2 with epoxides
| Autor: | Rafael Pavão das Chagas, Felipe T. Martins, Werberson de Almeida Bezerra, Bruno Noschang Cabral, Jorge L. S. Milani, Dayse Carvalho da Silva Martins, Alexandre Moreira Meireles |
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| Rok vydání: | 2019 |
| Předmět: |
Process Chemistry and Technology
chemistry.chemical_element 02 engineering and technology Manganese 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Porphyrin Cycloaddition 0104 chemical sciences Catalysis chemistry.chemical_compound chemistry Nucleophile Styrene oxide Polymer chemistry Chemical Engineering (miscellaneous) Molecule Propylene oxide 0210 nano-technology Waste Management and Disposal |
| Zdroj: | Journal of CO2 Utilization. 30:100-106 |
| ISSN: | 2212-9820 |
| DOI: | 10.1016/j.jcou.2018.12.017 |
| Popis: | A new free-base porphyrin, meso-tetrakis(2,3-dichlorophenyl)porphyrin, (H2T2,3-DCPP) and the respective manganese(III) complexes [MnIII(T2,3-DCPP)X] with six different axial ligands (NO3−, AcO−, IO3−, Br−, Cl−, HO−) were synthesized and characterized. The molecular structure of [MnIII(T2,3-DCPP)Cl] was also confirmed by single crystal X-ray diffraction. The complexes, when combined with tetrabutylammonium halides as nucleophile source cocatalysts, were highly active catalysts in the solvent-free cycloaddition reactions of carbon dioxide with styrene oxide, selectively producing the respective cyclic carbonate. The complex [MnIII(T2,3-DCPP)Cl] was used to evaluate a series of parameters in the system and efficiently catalyzed the transformation of various epoxides using TBAI as cocatalyst, 30 bar of CO2 at 100 °C, producing nearly quantitative conversions in most of the cases. Remarkable TON values of 500,000 and 434,780 were achieved, respectively, for propylene oxide and styrene oxide using [MnIII(T2,3-DCPP)Cl] as catalyst. Recycling experiments were conducted and the system maintains high conversion rates after eight runs, which indicated a high stability and reusability of the catalyst. |
| Databáze: | OpenAIRE |
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