@article{El Maliki_Bouachrine_Hamidi_Bejjit_Haddad_2011, title={Theoretical Studies on the Structural, Electronic and Optical Properties of the New π-conjugated Copolymers Based on Carbazole and Thiophene}, volume={4}, url={https://banglajol.info/index.php/JSR/article/view/7450}, DOI={10.3329/jsr.v4i1.7450}, abstractNote={<p>This work reports a theoretical investigation of π-conjugated oligomers constituted by <em>n</em> units (<em>n</em> = 1-4) based on carbazole and ethylenedioxythiophene. The molecular geometry, torsional potential, electronic and optical properties of the oligomers [Cbz-(Edot)<sub>n</sub>-Cbz] (<em>n</em> = 1-4) are investigated using DFT (B3LYP/3-21G*) calculations. The discussion is focused on the influence of chain length on the properties of these copolymers. The analyses of torsional angles for [Cbz-(Edot)<sub>4</sub>-Cbz] reveal that the structure has a anti-planar conformation. The electronic properties of the molecules, HOMO, LUMO and E<sub>g </sub>(HOMO-LUMO), are studied using B3LYP functional. The results have been compared with those of thiophene and ethylenedioxythiophene. The lowest excitation energies (E<sub>ex</sub>) and the maximal absorption wavelength (λ<sub>abs</sub>) are studied using the TD/DFT, ZINDO and CIS methods. The electronic transitions of the absorption spectrum derived by TD/DFT method give useful structural and electronic information for designing novel conducting organic polymer materials. The bridging effect by C=C(CN)<sub>2</sub> on the optoelectronic properties of the (carbazole-thiophene-carbazole) comonomer is investigated.</p> <p><em>Keywords</em>: Conducting polymer; Carbazole-(Ethylenedioxythiophene)<sub>n</sub>-Carbazole comonomers; DFT Optoelectronic properties; absorption coefficient; Bridging effect.</p> <p>© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. </p><p>doi: <a href="http://dx.doi.org/10.3329/jsr.v4i1.7450">http://dx.doi.org/10.3329/jsr.v4i1.7450</a></p><p>J. Sci. Res. <strong>4</strong> (1), 119-133 (2012)</p> <p> </p>}, number={1}, journal={Journal of Scientific Research}, author={El Maliki, Z. and Bouachrine, M. and Hamidi, M. and Bejjit, L. and Haddad, M.}, year={2011}, month={Dec.}, pages={119} }