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Updated: Aug 10, 2026

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Published on: October 18, 2018
Specific features of UV-vis absorption spectra of cis- and trans-polythiophenes
I Fuks-Janczarek1, I V Kityk, R Miedziński
1Solid State Department, Institute of Physics, J. Długosz University of Czestochowa, Al. Armii Krajowej 13/15, PL42201 Czestochowa, Poland.
Abstract:
UV-vis optical spectra of several polythiophene with number of dimers n=1, 5, 10, 15 for cis- and trans-forms were investigated. The study was done theoretically using semi-empirical AM1 (Austin Model 1) and PM3 (Parametric Method 3) methods with the appropriate molecular geometry optimization. The experimental UV-vis absorption spectra were used for verification of the both semi-empirical theoretical models. With the increasing number of dimers a red shift of the absorption edge was observed. Solvent does not play a crucial role on behavior of the absorption spectrum. A comparison of the both semi-empirical methods with the observed experimental absorption spectra is performed. Role of state dipole moments of the investigated polythiophenes in the behavior of the observed UV-vis spectra is discussed. Particular role of pi-conjugated bonds is demonstrated.
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