| Autor: |
Wu, Ling-Jo, Kottalanka, Ravi Kumar, Chu, Yu-Ting, Lin, Zheng-Ian, Chang, Chun-Juei, Ding, Shangwu, Chen, Hsuan-Ying, Wu, Kuo-Hui, Chen, Chih-Kuang |
| Předmět: |
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| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; 10/7/2024, Vol. 53 Issue 37, p15660-15673, 14p |
| Abstrakt: |
Titanium complexes bearing 2-(arylideneamino)phenolates and 2-((arylimino)methyl)phenolates were synthesized, and their catalytic activities in the polymerization of ε-caprolactone and L -lactide were studied. Among five-membered ring Ti complexes bearing 2-(arylideneamino)phenolates, FCl-Ti exhibited the highest level of catalytic activity ([CL] : [FCl-Ti] = 100 : 1, where [CL] = 2 M, and conv. = 86% at 60 °C after 9 h). For six-membered ring Ti complexes bearing 2-((arylimino)methyl)phenolates, SCl-Ti exhibited the highest level of catalytic activity ([CL] : [SCl-Ti] = 100 : 1, where [CL] = 2 M, and conv. = 88% at 60 °C after 118 h). The five-membered ring Ti complexes bearing 2-(arylideneamino)phenolates exhibited a higher level of catalytic activity (6.1–12.8 fold for the polymerization of ε-caprolactone and 6.2–23.0 fold for the polymerization of L -lactide) than the six-membered ring Ti complexes bearing 2-((arylimino)methyl)phenolates. The density functional theory (DFT) results revealed that the free energy of the first transition state FH-Ti-TS1 is 36.49 kcal mol−1 which is lower than that of SH-Ti-TS1 (46.58 kcal mol−1), which was ascribed to the fact that the Ti–Nim bond (2.742 Å) of FH-Ti-TS1 is longer than that of SH-Ti-TS1 (2.229 Å) and reduces the repulsion between ligands. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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