Synthesis, tuning of photophysical and electrochemical properties of Yellow-Red emissive, AIEE active benzamide dyes

Herein, Benzamide-based dyes were prepared by the multistep synthetic method and then characterized by various spectroscopic methods. The tuning in photophysical, aggregation-induced emission enhancement (AIEE) and electrochemical properties with alteration in molecular structure of dyes were studied in detail. Molecules possess weak push-pull interaction due to the existence of inbuilt charge transfer (CT) transition at 366-387 nm in absorption spectra. Dyes emit in yellow to red region with emission maxima at 560-599 nm in solution and 548-600 nm in the solid state. The notable positive solvatochromic effect and good Stoke's shift (9004-9717 cm(-1)) observed in dyes. Additionally, the existence of good solid-state emission and AIEE activity is desirable for its solid/aggregate state application in Organic light-emitting diodes. Besides, HOMO (-5.60 to -5.74 eV) and LUMO (-3.14 to -3.17 eV) energy levels comparable with reported ambipolar materials. Density functional theory (DFT) and time-dependent density-functional theory (TDDFT) calculations agree with the experimental photophysical and electrochemical data. The opto-electrochemical properties possessed by dyes undersign its suitable use in various optoelectronic applications.