Back to Search
Start Over
A comparative study of titanium complexes bearing 2-(arylideneamino)phenolates and 2-((arylimino)methyl)phenolates as catalysts for ring-opening polymerization of ε-caprolactone and L-lactide.
- Source :
- Dalton Transactions: An International Journal of Inorganic Chemistry; 10/7/2024, Vol. 53 Issue 37, p15660-15673, 14p
- Publication Year :
- 2024
-
Abstract
- 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, F<superscript>Cl</superscript>-Ti exhibited the highest level of catalytic activity ([CL] : [F<superscript>Cl</superscript>-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, S<superscript>Cl</superscript>-Ti exhibited the highest level of catalytic activity ([CL] : [S<superscript>Cl</superscript>-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 F<superscript>H</superscript>-Ti-TS1 is 36.49 kcal mol<superscript>−1</superscript> which is lower than that of S<superscript>H</superscript>-Ti-TS1 (46.58 kcal mol<superscript>−1</superscript>), which was ascribed to the fact that the Ti–N<superscript>im</superscript> bond (2.742 Å) of F<superscript>H</superscript>-Ti-TS1 is longer than that of S<superscript>H</superscript>-Ti-TS1 (2.229 Å) and reduces the repulsion between ligands. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14779226
- Volume :
- 53
- Issue :
- 37
- Database :
- Complementary Index
- Journal :
- Dalton Transactions: An International Journal of Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 179789857
- Full Text :
- https://doi.org/10.1039/d4dt02282c