A theoretical investigation on the absorption and emission properties of isomeric benzofuran trimers

The influence of isomeric conformation and substituent on the luminescent properties of two series of linear benzofuran trimers are studied. The structures, ionization potentials (IPs), electron affinities (EAs), and HOMO–LUMO gaps (ΔH–L) of the trimers are studied by the density functional theory with B3LYP functional. The calculation of the lowest excitation energies (Egs) and the maximal absorption wavelength λabs of trimers are performed employing time dependent density functional theory (TDDFT) and semi-empirical level ZINDO.