Unexpected thermally stable, cholesteric liquid-crystalline helical polyisocyanides with memory of macromolecular helicity.
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 degrees 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.
Hase
Yoko
Y
Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Mitsutsuji
Yuuki
Y
Ishikawa
Masayoshi
M
Maeda
Katsuhiro
K
Okoshi
Kento
K
Yashima
Eiji
E
D000577:Amides; D000588:Amines; D003486:Cyanides / Q000737:chemistry*; D006358:Hot Temperature; D050866:Liquid Crystals; D046911:Macromolecular Substances / Q000737:chemistry*; D008968:Molecular Conformation; D011108:Polymers
D000577:Amides; D000588:Amines; D003486:Cyanides; D046911:Macromolecular Substances; D011108:Polymers