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Thermotropic liquid–crystalline peptide derivatives: oligo(glutamic acid)s forming hydrogen-bonded columns

2005; Royal Society of Chemistry; Volume: 3; Issue: 5 Linguagem: Inglês

10.1039/b416474a

1477-0539

Masayuki Nishii, Toru Matsuoka, Yuko Kamikawa, Takashi Kato,

Liquid Crystal Research Advancements

We report on new thermotropic liquid-crystalline oligo(amino acid) derivatives forming columnar structures. These are based on branched oligo(glutamic acid)s and 2-(3,4-dialkyloxyphenyl)ethyl moieties. An oligo(glutamic acid) derivative, alpha,gamma-bis(L-glutamoyl) L-glutamic acid tetra[2-(3,4-dioctadecyloxyphenyl)ethyl]ester, shows a hexagonal columnar phase, whilst a glutamic acid derivative, alpha,gamma-bis[2-(3,4-dioctadecyloxyphenyl)ethyl] L-glutamate, does not show a mesophase. Hydrogen bonds formed by the oligo(glutamic acid) moieties should contribute to the induction of the columnar liquid-crystalline properties. In addition, we have examined the effects of the molecular chirality of the oligo(glutamic acid) parts and the functionalisation at the focal position of the taper shaped molecules on the liquid-crystalline properties of the compounds.