Polygonal Cylinder Phases of 3-Alkyl-2,5-diphenylthiophene-Based Bolaamphiphiles: Changing Symmetry by Retaining Net Topology

DOI: 10.1021/cm800509u

Authors: Xiaohong Cheng (Yunnan University) , Xing Dong (Yunnan University) , Rong Huang (Yunnan University) , Xiangbing Zeng (Department of Engineering Materials, University of Sheffield) , Goran Ungar (University of Sheffield) , Marko Prehm (Martin-Luther-University Halle-Wittenberg) , Carsten Tschierske (Martin-Luther-University Halle-Wittenberg)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials , VOL 20 (14) , PAGES 4729 - 4738

State: Published (Approved)
Published: July 2008

Abstract: Novel bolaamphilic triblock molecules consisting of a bent 2,5-diphenylthiophene unit, two terminal glycerol units, and a lateral n-alkyl chain have been synthesized via Ni- and Pd-catalyzed coupling reactions as key steps. The thermotropic liquid crystalline behavior of these compounds was investigated by polarized light optical microscopy, DSC, and X-ray scattering and the influence of the length of the lateral alkyl chains on the mesomorphic properties was studied. With elongation of the lateral alkyl chains, three different columnar phases (Colsqu/p4mm, Colsqu/p4gm and Colhex/p6mm), representing polygonal cylinder structures were found, where the cells have a square, pentagonal, and hexagonal cross-section, respectively. In the observed phase sequence, the change of the net topology is the same as seen for related linear biphenyl derived bolaamphiphiles, but the symmetry is increased, i.e, rectangular phases are replaced by square lattices.

Subject Areas: Chemistry, Materials


Instruments: I22-Small angle scattering & Diffraction

Added On: 24/01/2013 08:59

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