Synthesis of conjugated polymers with azobenzene moieties in the main chain

✍ Scribed by Atsushi Izumi; Masahiro Teraguchi; Ryoji Nomura; Toshio Masuda

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 148 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000401)38:7<1057::aid-pola2>3.0.co;2-5

✦ Synopsis

Poly(phenylenevinylene)-based conjugated polymers with azobenzene groups in the main chains were prepared by the Pd-catalyzed coupling polymerization of divinylarenes with dihaloarenes. The Pd-catalyzed coupling polymerization of 4,4Јdivinylazobenzene with dihaloarenes such as 1,3-dibromobenzene, 1,4-dibromo-2,5dihexylbenzene, 4,4Ј-dibromoazobenzene, and 4,4Ј-diiodoazobenzene resulted in polymers with poor solubility. In contrast, soluble polymers containing azobenzene moieties in the main chains were attainable from divinylbenzenes with 4,4Ј-dihaloazobenzenes if either or both of the monomers possessed hexyl groups on the aromatic rings. The number-average molecular weight of the polymer exceeded 10,000 under optimized conditions, and the polymer showed a remarkably redshifted absorption in the visible region (456 nm). 1 H NMR and IR spectra supported that the polymers having only trans-geometry for the double bonds.