Highly Isotactic and High-Molecular-Weight Poly(2-vinylpyridine) by Coordination Polymerization with Yttrium Bis(phenolate) Ether Catalysts

Abstract

The poly(2-vinylpyridine) combining highly isotactic (P m = 0.97) and high-molecular-weight (~10 5 g/mol) was obtained for the first time using novel yttrium bis(phenolate) ether catalysts.These catalysts also showed high activity and tolerance to low loadings. Computational studies and kinetic experiments provided a fundamental understanding of the initiation, propagation, and stereocontrol mechanism governing the polymerization reactions mediated by yttrium catalysts.

Metal‐Catalyzed Group‐Transfer Polymerization: A Versatile Tool for Tailor‐Made Functional (Co)Polymers

“…The group of Lu developed yttrium bis(phenolate)ether catalysts, in which the stereospecificity of the complex depended on the number of carbon atoms in the backbone of the ligand. P2VP with high isotacticity up to 97 % was obtained . The newly developed C 1 ‐symmetric (ONOO) R Y(CH 2 TMS)(THF) catalysts investigated by Rieger et al.…”

“…[27] Recently,t wo different approaches toward highly stereospecific2 VP-polymerization with non-metallocenel anthanides were established by the groups of Lu and Rieger. [28] The group of Lu developed yttrium bis(phenolate)ether catalysts, in which the stereospecificity of the complex depended on the number of carbon atoms in the backbone of the ligand. P2VP with high isotacticity up to 97 %w as obtained.…”

C–H Bond Activation of Silyl-Substituted Pyridines with Bis(Phenolate)Yttrium Catalysts as a Facile Tool towards Hydroxyl-Terminated Michael-Type Polymers

“…Since the first polymerization attempts, various organocatalysts, metallocenes and non-metallocenes 8-membered cyclic intermediate [1][2][3][4][5][6][7][8]. Since the first polymerization attempts, various organocatalysts, metallocenes and non-metallocenes were established for the synthesis of highly precise, tailor-made and functional polymers [3,5,[7][8][9][10][11][12][13][14]. The scope of available 1,4-Michael-type monomers ranges from differently substituted acrylates, methacrylates, acrylamides or nitrogen bearing monomers (e.g., 2-vinyl pyridine (2VP)) to vinyl lactone systems and phosphorous containing monomers, i.e., dialkyl vinyl phosphonates (DAVP) [5,7,15,16].…”

“…These catalysts were able to overcome the obstacles and produced high molecular weight polymers with very narrow molecular weight distributions and were in addition able to induce stereoinformation [10,15,[17][18][19][20][21]. This enhanced performance was achieved by e.g., introducing highly sterically demanding ligands to non-metallocenes for stereoregular polymerization of MMA or 2VP [9,10,21], by controlled polymerization of vinyl phosphonates using non-metallocenes, frustrated Lewis pairs or trivalent metallocenes [12,14,15,17,[22][23][24] or by utilizing C-H bond activation to obtain catalysts with higher initiator efficiencies [18]. Further to this, the synthesis of block copolymers was facilitated due to the living character of this polymerization type by simple sequential addition of different monomers with respect to their coordination strength to the metal center [7,25,26].…”

β‐Diketiminato Rare‐Earth Metal Complexes: The Influence of Monoatomic Substituents in the N‐aryl Moieties on Structures and Properties

“…These halogenated β‐diketiminato rare‐earth metal complexes 2 and 3 were utilized as catalysts for the polymerization of 2‐VP without or with [Ph 3 C][B(C 6 F 5 ) 4 ], and experimental results are summarized in Table . Although monoalkyl yttrium complexes supported by ene‐diamido, methoxyethylamino‐bis(phenolate) and ether‐bridged bis(phenolate) exhibited moderate activities and high isoselectivity toward 2‐VP polymerization, bis‐β‐diketiminato rare‐earth metal monoalkyl complexes 2 cannot promote the polymerization of 2‐VP within 600 min at ambient temperature (Table , runs 1 and 2), which was further confirmed with the in situ 1 H NMR spectra of mixture of complexes 2 and 2‐VP (Figures S22 and S23, Supporting Information). The inertness of complexes 2 toward 2‐VP is probably due to coordination saturation and the increase in electronegativity of electron‐withdrawing F substituent.…”