Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 22nd May 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 35, 2012
Previous Article Next Article

Heterolithic azobenzene-containing supermolecular tripedal liquid crystals self-organizing into highly segregated bilayered smectic phases

Author affiliations

Abstract

Synthesis, self-organization, and optical properties of supermolecular tripedal liquid crystals incorporating various prototypical mesogenic units such as alkoxy-azobenzene (AZB), alkoxy-biphenylene (BPH) or alkoxy-cyanobiphenyl (OCB) derivatives are reported. Different molecular systems were designed in order to sequentially incorporate the smectogenic-like alkoxy-azobenzene-based chromophore within the molecular structure, whose relative proportion is selectively varied by exchanging with the other mesogens. A divergent synthetic mode was elaborated for their synthesis, starting from the regioselective functionalization of the phloroglucinol-based (PG) inner core. This methodology allowed the preparation of several sets of unconventional tripedal oligomers with conjugated heterolithic structures (made of different blocks, e.g. PG6AZBxBPH3−x and PG6AZBxOCB3−x, x = 1 or 2) along the homolithic parents (all identical blocks, e.g. PGzAZB3, z = 6 or 11, z is the number of methylene in the spacer between PG and the protomesogen, PG6BPH3, and PG6OCB3), respectively. Essentially all the synthesized systems behave as thermotropic liquid crystals and show various types of highly segregated multilayered smectic phases, or, in one case, a nematic phase, depending on the nature of the constitutive anisotropic blocks and on the molecular topology (homolithic versus heterolithic, mesogenic ratio x : 3 − x). The effects of these structural modifications on the mesomorphism (mesophase structures, temperature ranges, and thermodynamic stability) have been investigated by differential scanning calorimetry and small-angle X-ray diffraction experiments combined with dilatometric measurements. Models describing the various supramolecular organizations of these tripedes into such multilayered structures are proposed and discussed. Preliminary results of the investigations of their optical properties will also be presented.

Graphical abstract: Heterolithic azobenzene-containing supermolecular tripedal liquid crystals self-organizing into highly segregated bilayered smectic phases

Back to tab navigation

Supplementary files

Publication details

The article was received on 11 Jun 2012, accepted on 16 Jul 2012 and first published on 17 Jul 2012


Article type: Paper
DOI: 10.1039/C2JM33751G
J. Mater. Chem., 2012,22, 18614-18622

  •   Request permissions

    Heterolithic azobenzene-containing supermolecular tripedal liquid crystals self-organizing into highly segregated bilayered smectic phases

    Z. T. Nagy, B. Heinrich, D. Guillon, J. Tomczyk, J. Stumpe and B. Donnio, J. Mater. Chem., 2012, 22, 18614
    DOI: 10.1039/C2JM33751G

Search articles by author

Spotlight

Advertisements