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Unexpected Thermally Stable, Cholesteric Liquid‐Crystalline Helical Polyisocyanides with Memory of Macromolecular Helicity
Author(s) -
Hase Yoko,
Mitsutsuji Yuuki,
Ishikawa Masayoshi,
Maeda Katsuhiro,
Okoshi Kento,
Yashima Eiji
Publication year - 2007
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200700051
Subject(s) - helicity , optically active , macromolecule , helix (gastropod) , amide , liquid crystalline , salt (chemistry) , materials science , dimethylformamide , crystallography , liquid crystal , chemistry , organic chemistry , physics , optoelectronics , ecology , biochemistry , particle physics , solvent , snail , biology
The achiral sodium salt of poly(4‐carboxyphenyl isocyanide) (poly‐ 1 –Na) folds into a one‐handed helix induced by optically active amines in water. The induced helicity remains when the optically active amines are completely removed, and further modification of the side groups to amide residues is possible without loss of memory of macromolecular helicity. Although the helical poly‐ 1 –Na loses its chiral memory at high temperature, helical polyisocyanides modified with achiral primary amines, which no longer have any chiral components, keep their memory perfectly even at 100 °C in N , N ‐dimethylformamide in some cases and exhibit cholesteric liquid‐crystalline phases, thus providing a robust scaffold with heat resistance to which a variety of functional groups can be introduced.