title: Thermotropic liquid-crystalline peptide derivatives: oligo(glutamic acid)s forming hydrogen-bonded columns.
abstract: 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.
authors.affiliation: Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nishii
authors.forename: Toru
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kamikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
mesh_terms: D000473:Alkanes / Q000737:chemistry; D000577:Amides / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D004987:Ethers / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry*; D006860:Hydrogen Bonding; D050866:Liquid Crystals / Q000737:chemistry*; D008859:Microscopy, Polarization; D008958:Models, Molecular; D015394:Molecular Structure; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D044367:Phase Transition; D013055:Spectrophotometry, Infrared; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D000473:Alkanes; D000577:Amides; D004987:Ethers; D005227:Fatty Acids; D009842:Oligopeptides; D018698:Glutamic Acid