A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity
Based on the ligand H<sub>4</sub>Salen-8<i><sup>t</sup></i>Bu (salen-<b>4</b>), a new dinuclear cobalt complex (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub> (salen-<b>4</b> = 3,5-di-<i>tert</i>-butylsalicylald...
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MDPI AG
2020-09-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/25/18/4095 |
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| author | Wen-Zhen Wang Kai-Yue Zhang Xin-Gang Jia Li Wang Lei-Lei Li Wei Fan Li Xia |
| author_facet | Wen-Zhen Wang Kai-Yue Zhang Xin-Gang Jia Li Wang Lei-Lei Li Wei Fan Li Xia |
| author_sort | Wen-Zhen Wang |
| collection | DOAJ |
| description | Based on the ligand H<sub>4</sub>Salen-8<i><sup>t</sup></i>Bu (salen-<b>4</b>), a new dinuclear cobalt complex (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub> (salen-<b>4</b> = 3,5-di-<i>tert</i>-butylsalicylaldehyde-3,3′-diaminobiphenylamine; TFA = trifluoroacetic acid) has been firstly synthesized and characterized. It shows high catalytic activity for the copolymerization of propylene oxide (PO) and carbon dioxide (CO<sub>2</sub>), yielding regioregular poly(propylene carbonate) (PPC) with little generation of propylene carbonate (PC) by-product. It has been found that (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub> shows higher activity at milder conditions, generating a polymer with maximum Mn of 293 kg/mol and a narrow molecular weight distribution PDI of 1.35. The influences of reaction time, CO<sub>2</sub> pressure, reaction temperature, nature of the cocatalyst, catalyst dosage and substrate concentration on the molecular weight, yield and selectivity of the polymer were explored in detail. The results showed that the (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub>/[PPN]TFA catalyst system demonstrated a remarkable TOF as high as 735 h<sup>–1</sup>. In addition, a hypothetical catalytic reaction mechanism was proposed based on density functional theory (DFT) calculations and the catalytic reaction results of the (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub>. |
| first_indexed | 2024-03-10T16:29:19Z |
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| language | English |
| last_indexed | 2024-03-10T16:29:19Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-123f926ec48e4b9e962295b22f1e8dcb2023-11-20T12:54:35ZengMDPI AGMolecules1420-30492020-09-012518409510.3390/molecules25184095A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and SelectivityWen-Zhen Wang0Kai-Yue Zhang1Xin-Gang Jia2Li Wang3Lei-Lei Li4Wei Fan5Li Xia6College of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaCollege of Chemistry and Chemical Engineering, Xi’an Shiyou University, Xi’an 710065, ChinaBased on the ligand H<sub>4</sub>Salen-8<i><sup>t</sup></i>Bu (salen-<b>4</b>), a new dinuclear cobalt complex (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub> (salen-<b>4</b> = 3,5-di-<i>tert</i>-butylsalicylaldehyde-3,3′-diaminobiphenylamine; TFA = trifluoroacetic acid) has been firstly synthesized and characterized. It shows high catalytic activity for the copolymerization of propylene oxide (PO) and carbon dioxide (CO<sub>2</sub>), yielding regioregular poly(propylene carbonate) (PPC) with little generation of propylene carbonate (PC) by-product. It has been found that (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub> shows higher activity at milder conditions, generating a polymer with maximum Mn of 293 kg/mol and a narrow molecular weight distribution PDI of 1.35. The influences of reaction time, CO<sub>2</sub> pressure, reaction temperature, nature of the cocatalyst, catalyst dosage and substrate concentration on the molecular weight, yield and selectivity of the polymer were explored in detail. The results showed that the (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub>/[PPN]TFA catalyst system demonstrated a remarkable TOF as high as 735 h<sup>–1</sup>. In addition, a hypothetical catalytic reaction mechanism was proposed based on density functional theory (DFT) calculations and the catalytic reaction results of the (salen-<b>4</b>)[Co(III)TFA]<sub>2</sub>.https://www.mdpi.com/1420-3049/25/18/4095carbon dioxidepropylene oxidepoly(propylene carbonate)copolymerization |
| spellingShingle | Wen-Zhen Wang Kai-Yue Zhang Xin-Gang Jia Li Wang Lei-Lei Li Wei Fan Li Xia A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity Molecules carbon dioxide propylene oxide poly(propylene carbonate) copolymerization |
| title | A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity |
| title_full | A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity |
| title_fullStr | A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity |
| title_full_unstemmed | A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity |
| title_short | A New Dinuclear Cobalt Complex for Copolymerization of CO<sub>2</sub> and Propylene Oxide: High Activity and Selectivity |
| title_sort | new dinuclear cobalt complex for copolymerization of co sub 2 sub and propylene oxide high activity and selectivity |
| topic | carbon dioxide propylene oxide poly(propylene carbonate) copolymerization |
| url | https://www.mdpi.com/1420-3049/25/18/4095 |
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