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An H‐Bonded Main‐Chain Liquid‐Crystalline Polymer Obtained by In Situ Photochemical Conversion from an H‐Bonded LC Dimer
Author(s) -
Kihara Hideyuki,
Tamaoki Nobuyuki
Publication year - 2008
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200800063
Subject(s) - dimer , moiety , chemistry , bifunctional , carboxylic acid , polymer chemistry , photochemistry , polymer , hydrogen bond , phase (matter) , organic chemistry , molecule , catalysis
An H‐bonded main‐chain liquid‐crystalline (LC) polymer was obtained by in situ photochemical conversion from an H‐bonded LC dimer. A bifunctional compound, 1 , having a cinnamoyl group at one end and a carboxylic acid group at the other, was synthesized as the H‐bonded LC dimer. UV irradiation of 1 in the LC phase in the presence of a sensitizer resulted in its conversion to a photodimer, with a carboxylic acid at both ends, through photocycloaddition of the cinnamoyl moiety. The LC phase was maintained during irradiation, because that of the photodimer was more thermally stable than that of 1 . FT‐IR analysis revealed that the carboxylic acids of the photodimer dominantly formed hydrogen bonds in the LC phase, which suggests that the photodimers assembled into an H‐bonded main‐chain LC polymer.