Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies
Two non-toxic potassium compounds, <b>1</b> and <b>2</b>, with a commercial oximate ligand have been prepared and fully spectroscopically characterized. Their activity as catalysts for the ring-opening polymerization (ROP) process of LLA has been studied, showing that they ar...
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| Format: | Article |
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MDPI AG
2022-07-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/15/2982 |
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| author | Christian Rentero Jesús Damián Asier Medel María Fernández-Millán Yolanda Rusconi Giovanni Talarico Tomás Cuenca Valentina Sessini Marta E. G. Mosquera |
| author_facet | Christian Rentero Jesús Damián Asier Medel María Fernández-Millán Yolanda Rusconi Giovanni Talarico Tomás Cuenca Valentina Sessini Marta E. G. Mosquera |
| author_sort | Christian Rentero |
| collection | DOAJ |
| description | Two non-toxic potassium compounds, <b>1</b> and <b>2</b>, with a commercial oximate ligand have been prepared and fully spectroscopically characterized. Their activity as catalysts for the ring-opening polymerization (ROP) process of LLA has been studied, showing that they are extremely active and able to polymerize the monomer in a few minutes. For derivative <b>2</b>, the presence of a crown ether in the potassium coordination sphere affects the nuclearity of the compound and consequently its solubility, with both aspects having an influence in the polymerization process. Detailed studies of the polymerization mechanism have been performed, and an unusual anionic mechanism was observed in absence of a co-initiator. Indeed, the monomer deprotonation generates a lactide enolate, which initiates the polymerization propagation. On the contrary, when a 1:1 ratio of cat:BnOH is used, a mixture of mechanisms is observed, the anionic mechanism and the activated monomer one, while from a cat:BnOH ratio of 1:2 and over, only the activated monomer mechanism is observed. |
| first_indexed | 2024-03-09T05:05:09Z |
| format | Article |
| id | doaj.art-7dfa17601bf44be89134c87e858ee3f0 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T05:05:09Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-7dfa17601bf44be89134c87e858ee3f02023-12-03T12:55:52ZengMDPI AGPolymers2073-43602022-07-011415298210.3390/polym14152982Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic StudiesChristian Rentero0Jesús Damián1Asier Medel2María Fernández-Millán3Yolanda Rusconi4Giovanni Talarico5Tomás Cuenca6Valentina Sessini7Marta E. G. Mosquera8Department of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80124 Napoli, ItalyDipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80124 Napoli, ItalyDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainDepartment of Organic and Inorganic Chemistry, Institute of Chemical Research “Andrés M. del Río” (IQAR), Universidad de Alcalá, Campus Universitario, 28871 Madrid, SpainTwo non-toxic potassium compounds, <b>1</b> and <b>2</b>, with a commercial oximate ligand have been prepared and fully spectroscopically characterized. Their activity as catalysts for the ring-opening polymerization (ROP) process of LLA has been studied, showing that they are extremely active and able to polymerize the monomer in a few minutes. For derivative <b>2</b>, the presence of a crown ether in the potassium coordination sphere affects the nuclearity of the compound and consequently its solubility, with both aspects having an influence in the polymerization process. Detailed studies of the polymerization mechanism have been performed, and an unusual anionic mechanism was observed in absence of a co-initiator. Indeed, the monomer deprotonation generates a lactide enolate, which initiates the polymerization propagation. On the contrary, when a 1:1 ratio of cat:BnOH is used, a mixture of mechanisms is observed, the anionic mechanism and the activated monomer one, while from a cat:BnOH ratio of 1:2 and over, only the activated monomer mechanism is observed.https://www.mdpi.com/2073-4360/14/15/2982catalyst designearth-abundant metal catalysissustainable chemistrygreen catalysis |
| spellingShingle | Christian Rentero Jesús Damián Asier Medel María Fernández-Millán Yolanda Rusconi Giovanni Talarico Tomás Cuenca Valentina Sessini Marta E. G. Mosquera Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies Polymers catalyst design earth-abundant metal catalysis sustainable chemistry green catalysis |
| title | Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies |
| title_full | Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies |
| title_fullStr | Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies |
| title_full_unstemmed | Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies |
| title_short | Ring-Opening Polymerization of <i>L</i>-Lactide Catalyzed by Potassium-Based Complexes: Mechanistic Studies |
| title_sort | ring opening polymerization of i l i lactide catalyzed by potassium based complexes mechanistic studies |
| topic | catalyst design earth-abundant metal catalysis sustainable chemistry green catalysis |
| url | https://www.mdpi.com/2073-4360/14/15/2982 |
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