First‐principles time‐dependent density‐functional theory study of functionalized benzo[b]thiophenes

We report a first-principles Time-Dependent Density-Functional Theory (TD-DFT) study of a new class of organic molecules, namely the branched Benzo[b]Thiophenes. We calculate excitation energies at different levels of theory, in order to evaluate the influence of excitonic contributions. We found a significant difference between the TD-DFT results obtained using a local or an non-local exchange-correlation energy functional: the latter is required to correctly describe intramolecular chargetransfer contributions, which we found to be present in these molecules. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)