Tuning the structural and electronic properties of novel thiophene-pyrrole based 1,2,3,4-tetrazine
Department of Chemistry, University of Gauhati, 781014 Guwahati, Assam, India
Received: 18 November 2016
Received in final form: 21 February 2017
Published online: 11 April 2017
Here, we have studied the structural and optoelectronic behaviour of a series of conjugated heterocyclic polymers. The basic monomer unit of the conjugated polymers contains a backbone of novel thiophene and pyrrole based 1,2,3,4-tetrazine. The other oligomers are designed by substituting the basic monomer unit with different electron-donating and electron-withdrawing groups at the nitrogen and the 3rd C-atom of the pyrrole and the thiophene ring respectively. We have calculated dihedral angles, HOMO-LUMO gaps, excitation energies and oscillator strengths by employing TD-DFT method. Our study reveals that compounds having bulky substituents exhibit larger dihedral angles. This in turn renders an increase in the band gaps (ΔH − L). Presence of the electron-withdrawing substituents also increases the ΔH − L values of the oligomers. However, the electron-donating groups decrease the ΔH − L values of the oligomers. Therefore, small electron-donating substituents have an overwhelming effect on the optoelectronic properties of the conjugated polymers which in turn makes them interesting materials with good conduction properties for fabrication of optoelectronic devices such as OLEDs, OFETs and solar cells.
Key words: Molecular Physics and Chemical Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017