Density functional theory investigation of substituent effects on building blocks of conducting polymers

Salzner, U.2016-02-082016-02-0819990379-6779http://hdl.handle.net/11693/25249Substituted heterocyclic dimers were calculated employing density functional theory (DFT) and analyzed with the natural bond orbits method (NBO). Substitution in 3- and 4-positions leads to parallel shifting of HOMO and LUMO but does not reduce energy gaps. For bridge dimers, HOMO-LUMO gaps correlate with π-electron densities in the carbon backbone and energy gap reduction correlate with the strength of π-π* interactions from the backbone to the bridging group. Alternating donor-acceptor groups do not reduce energy gaps and lead to systems with average HOMO and LUMO levels compared to the parent molecules.EnglishCalculationsChemical bondsElectron energy levelsElectronic density of statesEnergy gapPolypyrrolesProbability density functionSemiconductor quantum wellsSubstitution reactionsAromatic polymersCarrier concentrationDimersSulfur compoundsSubstituent effectsSubstituted heterocyclic dimersNatural bond orbital method (NBO)PolythiophenesOrganic polymersSemiconducting polymersDensity functional theory investigation of substituent effects on building blocks of conducting polymersArticle10.1016/S0379-6779(98)01240-5