Semiconducting Oligomers of 1,4-dimethoxybenzene, Thiophene and Thiazole: A Theoretical Study
Sawadogo René
Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, UFR/SEA 03 BP 7021, Burkina Faso and Institut des Sciences Analytiques et de Physico-Chimie Pour l'Environnement et les Matériaux, IPREM UMR CNRS 5254, Equipe Chimie-Physique, Pau France, France
Diendéré Françoise *
Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, UFR/SEA 03 BP 7021, Burkina Faso
Guiguemdé Issaka
Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, UFR/SEA 03 BP 7021, Burkina Faso
Ouédraogo Raguilnaba
Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, UFR/SEA 03 BP 7021, Burkina Faso
Sotiropoulos Jean-Marc
Institut des Sciences Analytiques et de Physico-Chimie Pour l'Environnement et les Matériaux, IPREM UMR CNRS 5254, Equipe Chimie-Physique, Pau France, France
*Author to whom correspondence should be addressed.
Abstract
Organic semiconducting oligomers containing three to nine heterocyclic units and based on 1,4-dimethoxybenzene, thiophene and thiazole have been studied by DFT and TDDFT at the B3LYP/6-31G(d,p) level. The energy of each molecule, those of the frontier orbitals HOMO and LUMO, the width of the band gaps and the optical properties have been calculated. The inter-ring distances, dihedral angles and torsional angles have been elucidated. These molecules are planar π-conjugated systems. The band gaps of the longer oligomers studied range from 2.53 to 2.72 eV and their excitation energies calculated by TDDFT vary from 2.22 to 2.36 eV. Wavelengths of absorption bands of 524 to 556 nm are also obtained by TDDFT. The results of this theoretical study show that these organic molecules have interesting properties and can potentially be used as components in solar cells.
Keywords: DFT, TDDFT, semiconducting oligomers, oligomers of 1,4-dimethoxybenzene, HOMO, LUMO, band gap, excitation energy