In this work, five 3,6,11-trisubstituted-dibenzo[a,c]phenazine (2–6) derivatives were synthesized by employing Palladium-catalyzed Suzuki–Miyaura ‘C–C bond’ coupling reaction and characterized. Absorption spectra of 2–6 show the formation of charge-transfer complexes. Dyes exhibit blue-green fluorescence with emission maxima 434–506 nm in various solvents and neat solid film. To elucidate AIE phenomenon, photophysical properties of dye 2 and 3 in different THF/water mixture were studied. The HOMO and LUMO energy level were found in the range of − 6.38 to − 6.82 eV and − 3.67 to − 3.75 eV with an electrochemical bandgap of 2.71–3.08 eV. The HOMO and LUMO distribution in molecules were further studied by DFT/TD–DFT calculations. Herein, characteristic blue emission, comparable energy levels with n-type materials, and good thermal stability of derivatives make them a potential candidate for their application in optoelectronics.
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Keywords: Donor–acceptor system; Suzuki–Miyaura coupling; Photophysical studies; Aggregation-induced emission (AIE); HOMO and LUMO energy level; n-type materials