Synthesis, crystal structure and photo- and electro-luminescence of the coumarin derivatives with benzotriazole moiety

Two new coumarin derivatives containing an electron-transporting moiety (benzotriazole), 7-N,N-diethylamino-3-(benzotriazol-1-yl)coumarin (DABTC-1) and 7-N,N-diethylamino-3-(benzotriazol-2-yl)coumarin (DABTC-2), were synthesized and characterized by element analysis, 1H NMR, FT-IR and UV–vis absorption spectra. Their structures were determined by X-ray crystallography single crystal analysis. The photoluminescent behaviors of the compounds in both solution and solid states were observed, they exhibit strong blue and blue–green emissions under ultraviolet light excitation, respectively. The energy levels of the HOMO and LUMO of the compounds have been calculated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at B3LYP/6-31G(d) level. The electroluminescent devices with the compounds as the emitters were fabricated.