Novel Benzoate Ester Acceptor Based Molecules Synthesis, Optical Properties and DFT-TDDFT Computational Study

Novel functional materials CAZ-TAZ-MBZ, PTZ-TAZ-MBZ, and DPA-TAZ-MBZ were synthesized via click chemistry and systematically examined for their photo physical and electronic characteristics. Optical studies revealed absorption maxima between 306 and 344 nm, with PTZ-TAZ-MBZ exhibiting the most intense fluorescence emission at 560 nm. Density functional theory (DFT) and time-dependent DFT calculations at the B3LYP/6–31 G* level confirmed significant spatial separation between the HOMO and LUMO in the ground state, while natural transition orbital (NTO) analysis highlighted donor-localized HONTO and acceptor-concentrated LUNTO distributions. Notably, the singlet-triplet energy gaps (ΔEST) were calculated as 0, 0.1044, and 0.0018 eV, suggesting efficient reverse intersystem crossing and potential for thermally activated delayed fluorescence. These findings demonstrate that methyl benzoate serves as an effective acceptor, providing a versatile platform for donor tuning. The promising charge transfer characteristics and tunable photo physical properties of these materials suggest their potential application in organic light-emitting diodes and other optoelectronic devices. Future efforts will focus on optimizing molecular design to achieve highly efficient blue and deep-blue emissive materials.