Excited state energy distributions in stereo selective white light emission of 1,2-dibenzthiazolyl ethylene isomers

A detailed study on the influence of stereo specificity, which controls the photo emission characteristics of two dibenzthiazolyl ethylene (DBE) stereoisomers has been carried out using experimental time resolved measurements followed by a configuration interaction semi-empirical calculations. The differences in the photo emission effects are mainly governed by the intra-molecular steric effects, leading to the differences in solid-state packing order having a dihedral angle of ϕ ∼ 40° in cis form and ϕ ∼ 177° in the trans form, more importantly, differences in the intra-molecular electron density distribution causing ‘charge redistribution’ in the excited state.