Original language | English |
---|---|
Pages (from-to) | 504-511 |
Number of pages | 8 |
Journal | Applied Organometallic Chemistry |
Volume | 28 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2014 |
Keywords
- zinc
- N-heterocyclic carbene
- polymerization
- trimethylene carbonate
- lactide
- EPSILON-CAPROLACTONE POLYMERIZATION
- GROUP-4 METAL-COMPLEXES
- SINGLE-SITE CATALYSTS
- RAC-LACTIDE
- CYCLIC ESTERS
- STRUCTURAL-CHARACTERIZATION
- COORDINATION CHEMISTRY
- LIGANDS SYNTHESIS
- PHENOLATE LIGANDS
- ACTIVATED MONOMER
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TY - JOUR
T1 - Controlled ring-opening polymerization of trimethylene carbonate and access to PTMC-PLA block copolymers mediated by well-defined N-heterocyclic carbene zinc alkoxides
AU - Fliedel, Christopher Daniel
AU - Mameri, Samir
AU - Dagorne, Samuel
AU - Avilés, Maria Teresa
PY - 2014/7
Y1 - 2014/7
N2 - Four novel Zinc-NHC alkyl/alkoxide/chloride complexes (4, 5, 9 and 9) were readily prepared and fully characterized, including X-ray diffraction crystallography for 5 and 9. The reaction of N-methyl-N-butyl imidazolium chloride (3.HCl) with ZnEt2 (2 equiv.) afforded the corresponding [(CNHC)ZnCl(Et)] complex (4) via a protonolysis reaction, as deduced from NMR data. The alcoholysis of 4 with BnOH led to quantitative formation of the dinuclear Zn(II) alkoxide species [(CNHC)ZnCl(OBn)]2 (5), as confirmed by X-ray diffraction analysis. The NMR data are in agreement with species 5 retaining its dimeric structure in solution at room temperature. The protonolysis reaction of N-(2,6-diisopropylphenyl)-N-ethyl methyl ether imidazolium chloride (8.HCl) with ZnEt2 (2 equiv.) yielded the [(CNHC)ZnCl(Et)] species 9. The latter was found to be reactive with CH2Cl2 in solution and to cleanly convert to the corresponding Zn(II) dichloride [(CNHC)ZnCl2]2 (9), whose molecular structure was also elucidated using X-ray diffractometry. Unlike Zn(II)-NHC alkoxide species 1 and 2, which contain a NHC flanked with an additional N-functional group (i.e. thioether and ether, respectively), the Zn(II) alkoxide species 5 incorporates a monodentate NHC ligand. The Zn(II) complexes 1, 2 and 5 were tested in the ring-opening polymerization (ROP) of trimethylene carbonate (TMC). All three species are effective initiators for the controlled ROP of trimethylene carbonate, resulting in the production of narrow disperse PTMC material. Initiator 1 (incorporating a thioether moiety) was found to perform best in the ROP of TMC. Notably, the latter also readily undergoes the sequential ROP of TMC and rac-LA in the presence of a chain-transfer agent, leading to well-defined and high-molecular-weight PTMC/PLA block copolymers. Copyright (c) 2014 John Wiley & Sons, Ltd.
AB - Four novel Zinc-NHC alkyl/alkoxide/chloride complexes (4, 5, 9 and 9) were readily prepared and fully characterized, including X-ray diffraction crystallography for 5 and 9. The reaction of N-methyl-N-butyl imidazolium chloride (3.HCl) with ZnEt2 (2 equiv.) afforded the corresponding [(CNHC)ZnCl(Et)] complex (4) via a protonolysis reaction, as deduced from NMR data. The alcoholysis of 4 with BnOH led to quantitative formation of the dinuclear Zn(II) alkoxide species [(CNHC)ZnCl(OBn)]2 (5), as confirmed by X-ray diffraction analysis. The NMR data are in agreement with species 5 retaining its dimeric structure in solution at room temperature. The protonolysis reaction of N-(2,6-diisopropylphenyl)-N-ethyl methyl ether imidazolium chloride (8.HCl) with ZnEt2 (2 equiv.) yielded the [(CNHC)ZnCl(Et)] species 9. The latter was found to be reactive with CH2Cl2 in solution and to cleanly convert to the corresponding Zn(II) dichloride [(CNHC)ZnCl2]2 (9), whose molecular structure was also elucidated using X-ray diffractometry. Unlike Zn(II)-NHC alkoxide species 1 and 2, which contain a NHC flanked with an additional N-functional group (i.e. thioether and ether, respectively), the Zn(II) alkoxide species 5 incorporates a monodentate NHC ligand. The Zn(II) complexes 1, 2 and 5 were tested in the ring-opening polymerization (ROP) of trimethylene carbonate (TMC). All three species are effective initiators for the controlled ROP of trimethylene carbonate, resulting in the production of narrow disperse PTMC material. Initiator 1 (incorporating a thioether moiety) was found to perform best in the ROP of TMC. Notably, the latter also readily undergoes the sequential ROP of TMC and rac-LA in the presence of a chain-transfer agent, leading to well-defined and high-molecular-weight PTMC/PLA block copolymers. Copyright (c) 2014 John Wiley & Sons, Ltd.
KW - zinc
KW - N-heterocyclic carbene
KW - polymerization
KW - trimethylene carbonate
KW - lactide
KW - EPSILON-CAPROLACTONE POLYMERIZATION
KW - GROUP-4 METAL-COMPLEXES
KW - SINGLE-SITE CATALYSTS
KW - RAC-LACTIDE
KW - CYCLIC ESTERS
KW - STRUCTURAL-CHARACTERIZATION
KW - COORDINATION CHEMISTRY
KW - LIGANDS SYNTHESIS
KW - PHENOLATE LIGANDS
KW - ACTIVATED MONOMER
U2 - 10.1002/aoc.3154
DO - 10.1002/aoc.3154
M3 - Article
VL - 28
SP - 504
EP - 511
JO - Applied Organometallic Chemistry
JF - Applied Organometallic Chemistry
SN - 0268-2605
IS - 7
ER -