Jump to main content
Jump to site search

Issue 4, 2017
Previous Article Next Article

Star-shaped π-gelators based on oxadiazole and thiadiazoles: a structure–property correlation

Author affiliations

Abstract

Star-shaped and tetracatenar molecules based on 1,3,4-oxadiazole and thiadiazole derivatives were synthesized and their liquid crystallinity and gelation behavior were studied. The self-assembly and photophysical properties of these molecules are sensitive to the type of the heteroatom present in the molecule and the pattern of peripheral substitution. Only the star-shaped molecule with substituted oxadiazole arms exhibited a columnar hexagonal phase, while the tetracatenars were crystalline. This compound exhibited a supergelation behavior that is mainly supported by attractive π–π interactions. This is notable because usually supergelation is supported by H-bonding interactions. Further, this compound exhibited aggregation-induced emission with a several-fold increase in the luminescence intensity upon gelation. Surprisingly its thiadiazole counterpart was crystalline and did not gelate. The corresponding oxadiazole and thiadiazole star-shaped molecules, with peripheral 3,4-substitution, were liquid crystalline and stabilized gelation. This shows that in addition to π–π interactions, nanosegregation of incompatible molecular subunits like flexible tails plays a major role in organogelation and liquid crystalline self-assembly. Microscopy studies revealed a fibrillar network of several micrometers length confirming the long range molecular self-assembly. Electrochemical studies helped to understand the effect of peripheral substitution on the HOMO–LUMO levels and the band gaps.

Graphical abstract: Star-shaped π-gelators based on oxadiazole and thiadiazoles: a structure–property correlation

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 May 2017, accepted on 21 Jul 2017 and first published on 21 Jul 2017


Article type: Paper
DOI: 10.1039/C7ME00040E
Citation: Mol. Syst. Des. Eng., 2017,2, 478-489
  •   Request permissions

    Star-shaped π-gelators based on oxadiazole and thiadiazoles: a structure–property correlation

    S. Nath, S. K. Pathak, J. De, S. K. Pal and A. S. Achalkumar, Mol. Syst. Des. Eng., 2017, 2, 478
    DOI: 10.1039/C7ME00040E

Search articles by author

Spotlight

Advertisements