at Google ScholarTitle data
Ghosh, Swarup ; Glöckler, Eduard ; Wölper, Christoph ; Tjaberings, Alexander ; Gröschel, André H. ; Schulz, Stephan:
Active Ga-catalysts for the ring opening homo- and copolymerization of cyclic esters, and copolymerization of epoxide and anhydrides.
In: Dalton Transactions.
Vol. 49
(2020)
Issue 38
.
- pp. 13475-13486.
ISSN 1477-9234
DOI: https://doi.org/10.1039/D0DT02831B
Abstract in another language
A series of gallium complexes L12Ga4Me8 (1), L22Ga4Me8 (2), and L32Ga4Me8 (3) was synthesized by reaction of GaMe3 with Schiff base ligands L1–3H2 (L1H2 = 2,4-di-tert-butyl-6-{[(3-hydroxypropyl)imino]methyl}phenol; L2H2 = 2,4-dichloro-6-{[(3-hydroxypropyl)imino]methyl}phenol; L3H2 = 4-tert-butyl-2-{[(3-hydroxypropyl)imino]methyl}phenol) and characterized by 1H, 13C NMR, IR spectroscopy, elemental analysis and single crystal X-ray analysis (1, 2), proving their tetranuclear structure in the solid state. Complexes 1–3 showed good catalytic activity in the ring opening homopolymerization (ROP) and ring opening copolymerization (ROcoP) of lactide (LA) and ε-caprolactone (ε-CL) in the presence of benzyl alcohol (BnOH) in toluene at 100 °C, yielding polymers with the expected average molecular weights (Mn) and narrow molecular weight distributions (MWD), as well as a high isoselectivity for the ROP of rac-lactide (rac-LA), yielding isotactic-enriched PLAs with Pm values up to 0.78. Kinetic studies with complex 1 proved the first order dependence on monomer concentration, while mechanistic studies confirmed the coordination insertion mechanistic (CIM) pathway. Sequential addition of monomers gave well defined diblock copolymers of PCL-b-PLLA and PLLA-b-PCL, proving the living character of the polymerization reactions. The catalysts also showed perfect selectivity for the copolymerization of cyclohexene oxide (CHO) with both succinic anhydride (SA) and maleic anhydride (MA) in the presence of BnOH and produced >99% alternating block copolymers.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Institutions of the University: | Research Institutions > Central research institutes > Bayerisches Zentrum für Batterietechnik - BayBatt Research Institutions Research Institutions > Central research institutes Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Polymer Materials for Electrochemical Storage > Chair Polymer Materials for Electrochemical Storage - Univ.-Prof. Dr. André Gröschel |
| Result of work at the UBT: | No |
| DDC Subjects: | 500 Science > 540 Chemistry |
| Date Deposited: | 28 Jul 2023 07:10 |
| Last Modified: | 02 Aug 2023 07:53 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/86385 |