Synthesis and properties of fluorinated benzotriazole‐based donor‐acceptor‐type conjugated polymers via Pd‐catalyzed direct CH/CH coupling polymerization. Issue 3 (10th January 2021)

• Record Type: Journal Article
• Authors: Li, Jingwen; Han, Dong; Zhang, Qiang; He, Zewang; Lu, Yan
• Is Part Of: Journal of polymer science. Volume 59:Issue 3(2021)
• Page Start: 240
• Page End: 250
• Publication Date: 2021-01-10
• Subjects: CH/CH coupling -- conjugated polymers -- fluorinated benzotriazole -- optoelectronic properties -- Pd‐catalyzed polymerization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymerization; Polymers; Periodicals; 547.7
• DOI: 10.1002/pol.20200716
• Languages: English
• ISSNs: 2642-4150

Abstract

Abstract: Fluorine substituted benzotriazole (BTz) units have shown great potential in improving various conjugated polymers (CPs)‐based optoelectronic devices' performance. Thus, it is highly expected for the establishment of simple, efficient, and inexpensive accesses to such polymers. In this paper, Pd‐catalyzed direct CH/CH coupling polymerization is first employed for the synthesis of 5, 6‐difluorobenzotriazole containing π‐CPs, which fully avoids prefunctionalization of monomers. Under the optimized conditions, a series of donor‐acceptor‐type π‐CPs with excellent regio‐regularity are facilely obtained via the direct CH/CH coupling reaction of 5, 6‐difluoro‐2‐(2‐hexyldecyl)‐2H‐BTz with different thiophene analogs. The chemical structure of the as‐synthesized polymers are confirmed by NMR technique including 1 H NMR, 19 F NMR, and the edited heteronuclear singular quantum correlation and heteronuclear multiple bond correlation spectra as well as comparative study on the same polymers obtained via Stille coupling and direct (hetero)arylation polymerization. Further, their optical properties, electrochemical properties, and thermal stabilities are also carefully explored by UV–Vis absorption spectra, cyclic voltammograms as well as thermogravimetric analysis, respectively. On the basis of density functional theory (DFT) simulation, the effect of alkyl substituents attached to thiophene units on the reactivity and optical performance of the resultant polymers is explained. Our protocol exhibits remarkable advantages in synthetic simplicity, atom‐economy, high efficiency, and excellent regioselectivity of cross‐coupling, providing an alternative synthetic strategy for high‐performance optoelectronic materials. Abstract : A series of benzotriazole‐based donor‐acceptor‐type conjugated polymers with regularly alternating structures are directly synthesized without any pre‐functionalization of the starting monomers. The protocol developed in this study exhibits remarkable advantages in synthetic simplicity, atom‐economy, high efficiency, and excellent regioselectivity of cross‐coupling.