Synthesis and photoisomerization properties of polynorbornenes with azobenzene chromophores

Suk Hoon Kang, Hee Deuk Shin, Cha Hwan Oh, Dong Hoon Choi, Ki Hong Park

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14 Citations (Scopus)

Abstract

We successfully synthesized the addition-type polynorbonenes (PNB) exhibiting photochromic properties and excellent thermal stability. Three norbornene-based monomers with different azobenzene moiety (R=NO2, H, OCH3) were synthesized by transesterification method. The corresponding PNB copolymers were synthesized by transition metal-catalyzed addition polymerization method, and characterized by GPC, UV-Vis spectroscopy, NMR, and thermal analysis. For comparison of the photochromic properties depending on the rigidity of polymer backbone, we prepared the polymethylmethacrylate (PMMA) copolymer with the corresponding azobenzene moiety. We investigated the photoisomerization behavior by means of optical muitichannel analyzer with Xe lamp as well as real-time UV-Vis spectroscopy with high-pressure mercury lamp. Among three PNB copolymers, a polymer with azobenzene (R=H) was the most adaptable for observation of photoisomerization behavior. It was found that the rate of photoisomerization and relaxation depended on the structure of azobenzene chromophore, rather than that of polymer backbone.

Original languageEnglish
Pages (from-to)957-963
Number of pages7
JournalBulletin of the Korean Chemical Society
Volume23
Issue number7
Publication statusPublished - 2002 Jul 20
Externally publishedYes

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Keywords

  • Azobenzene
  • Photochromic
  • Photoisomerization
  • Polynorbornene

ASJC Scopus subject areas

  • Chemistry(all)

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