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

Abstract

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.