Jump to main content
Jump to site search

Issue 10, 2017
Previous Article Next Article

Chiroptical response inversion upon sample flipping in thin films of a chiral benzo[1,2-b:4,5-b′]dithiophene-based oligothiophene

Author affiliations

Abstract

A new chiral benzo[1,2-b:4,5-b′]dithiophene-based oligothiophene has been synthesized and spectroscopically characterized in solution and in the solid state. The electronic circular dichroism (ECD) spectra of the thin films revealed the occurrence of an uncommon phenomenon, consisting of the inversion of the circular dichroism sign by sample flipping. To the best of our knowledge, this is unprecedented in samples where no preferential orientation of the chromophores has been induced, and must be due to spontaneous local anisotropies. It reveals peculiar features upon the usual solvent annealing procedure, but finally results in stable and very strong signals, which are perfectly reproduced in sign, and relative and even absolute magnitude. Although the recorded signal cannot be considered as a true ECD spectrum, it corresponds to a very large discrimination of light circular polarization, which is well explained by means of the Mueller matrix analysis and does not depend on instrumental defects. It is a genuine property of this material, which correlates with polarized optical microscopy (POM) images and only depends on the self-assembling properties of this molecule. This phenomenon may have relevant implications, on account of its strength and of the interest of oligothiophenes in current optoelectronic devices.

Graphical abstract: Chiroptical response inversion upon sample flipping in thin films of a chiral benzo[1,2-b:4,5-b′]dithiophene-based oligothiophene

Back to tab navigation

Supplementary files

Publication details

The article was received on 23 May 2017, accepted on 20 Jun 2017 and first published on 20 Jun 2017


Article type: Research Article
DOI: 10.1039/C7QM00233E
Citation: Mater. Chem. Front., 2017,1, 2047-2056
  •   Request permissions

    Chiroptical response inversion upon sample flipping in thin films of a chiral benzo[1,2-b:4,5-b′]dithiophene-based oligothiophene

    G. Albano, M. Lissia, G. Pescitelli, L. A. Aronica and L. Di Bari, Mater. Chem. Front., 2017, 1, 2047
    DOI: 10.1039/C7QM00233E

Search articles by author

Spotlight

Advertisements