A TD-DFT study of the optical properties of (2,7-fluorene)-heterocyclic derivatives

► Nine (2,7-fluorene)-heterocyclic derivatives were studied by B3LYP theory. ► The absorption and emission spectra of the models were predicted by TD-B3LYP theory. ► The lowest singlet excited state is dominated by HOMO-LUMO electronic transition. ► Model F(TQ)F has the lowest excitation energy by 1.91 eV.