TY - JOUR
T1 - Insights into the interaction between bis(aryloxide)alkylaluminum and N-heterocyclic carbene
T2 - from an abnormal Lewis adduct to a frustrated Lewis pair for efficient polymerizations of biomass-derived acrylic monomers
AU - Wang, Xing
AU - Zhang, Yanping
AU - Hong, Miao
N1 - This work was supported by the National Key R&D Program of China (2021YFA1501700), the National Natural Science Foundation of China (grant no. 51973232, 22201292, and 21821002), the Science and Technology Commission of Shanghai Municipality (grant no. 22ZR1481900 and 23XD1424600), and the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry from Changchun Institute of Applied Chemistry, Chinese Academy of Sciences.
PY - 2023/6/14
Y1 - 2023/6/14
N2 - This contribution presents the development of a general Lewis pair (LP) catalyst for efficient and/or controlled polymerizations of inert biomass-derived acrylic monomers, including methyl crotonate (MC), (E,E)-methyl sorbate (MS), and β-angelica (β-AL). Through a comprehensive study on the interaction between bis(aryloxide)alkylaluminum Lewis acids (LAs) and N-heterocyclic carbene (NHC) Lewis bases (LBs), a new frustrated Lewis pair (FLP) has been constructed which comprises MeAl(BHT)2 (BHT: 2,6-di-tert-butyl-4-methylphenoxide) and 1,3-di-tert-butyl-4,5-dimethylimidazol-2-ylidene (Me-ItBu). Such a FLP can mediate efficient polymerizations of MS, MC, and β-AL regardless of the addition sequence, on account of its stability without the formation of abnormal Lewis adducts and the noninteracting FLP feature that enables sufficiently “free” LAs and LBs with suitable steric hindrance for catalysis. Moreover, a high degree of control over the polymerization of MS has also been achieved using the MeAl(BHT)2/Me-ItBu FLP, affording PMSs with high Mn up to 600.3 kg mol−1. An exclusive initiation via a basic mechanism in the polymerization of MS has been revealed, leading to the formation of linear PMSs with a unique conjugated diene chain end that brought about significantly enhanced thermal stability of the resultant PMSs.
AB - This contribution presents the development of a general Lewis pair (LP) catalyst for efficient and/or controlled polymerizations of inert biomass-derived acrylic monomers, including methyl crotonate (MC), (E,E)-methyl sorbate (MS), and β-angelica (β-AL). Through a comprehensive study on the interaction between bis(aryloxide)alkylaluminum Lewis acids (LAs) and N-heterocyclic carbene (NHC) Lewis bases (LBs), a new frustrated Lewis pair (FLP) has been constructed which comprises MeAl(BHT)2 (BHT: 2,6-di-tert-butyl-4-methylphenoxide) and 1,3-di-tert-butyl-4,5-dimethylimidazol-2-ylidene (Me-ItBu). Such a FLP can mediate efficient polymerizations of MS, MC, and β-AL regardless of the addition sequence, on account of its stability without the formation of abnormal Lewis adducts and the noninteracting FLP feature that enables sufficiently “free” LAs and LBs with suitable steric hindrance for catalysis. Moreover, a high degree of control over the polymerization of MS has also been achieved using the MeAl(BHT)2/Me-ItBu FLP, affording PMSs with high Mn up to 600.3 kg mol−1. An exclusive initiation via a basic mechanism in the polymerization of MS has been revealed, leading to the formation of linear PMSs with a unique conjugated diene chain end that brought about significantly enhanced thermal stability of the resultant PMSs.
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U2 - 10.1039/d3py00546a
DO - 10.1039/d3py00546a
M3 - Article
AN - SCOPUS:85163797463
SN - 1759-9954
VL - 14
SP - 3286
EP - 3293
JO - Polymer Chemistry
JF - Polymer Chemistry
IS - 28
ER -