2,3-Diphenylquinoxalin-6-yl based dyes: Synthesis and studies of photophysical, aggregation-induced emission enhancement and electrochemical properties

Abstract

Herein, 2,3-diphenylquinoxalin-6-yl based derivatives were synthesized, characterized by various spectroscopic method and studied for photophysical, aggregation-induced emission enhancement (AIEE) and electrochemical properties. Existence of intramolecular charge transfer transition (ICT) at 372−379 nm in absorption spectra of molecules confer weak push-pull interaction within it. Broad range of emission from blue to orange with λem = 412−592 nm in dyes arose from different energy state emission viz., locally excited (LE), Twisted intramolecular charge transfer (TICT) and excimer emission. Switching in emission state of molecules from excimer to TICT emission were observed by changing the polarity of solvent due to stabilization of TICT in polar media. Dyes have good solid state emission and AIEE activity desirable for its solid/aggregate state application in OLED's. Good Stokes shift (2183−9703 cm−1), thermal stability and comparable HOMO (−5.65 to −6.02 eV) energy levels with reported hole transporting materials confer desirable role of molecules in various optoelectronic applications. Further, DFT calculation of dyes, designate comparable experimental and theoretical photophysical and electrochemical properties with respect to structure of dyes.