Experimental and Computational Optoelectrochemical Investigation of Quinoxaline Based Charge Transfer Derivatives: Green-Orange Emissive, AIEE Active Materials

Abstract

2,3-Diphenylquinoxalin-6-yl based dyes were synthesized and characterized using ¹H, ¹³C, HRMS and NOSEY spectroscopic technique. The comprehensive photophysical, aggregation-induced emission enhancement (AIEE) activity, electrochemical and theoretical studies of dyes explored. The intramolecular charge transfer transition (ICT) at 380–386 nm in absorption spectra suggest weak push-pull feature of dyes. Dyes show emission in green to orange region (λ_max: 561–588 nm) in solvent as well as solid state. The Stokes shift of dyes is 7979–9167 cm⁻¹. The minimal positive solvatochromism (slight variation in λ_emi) own by dyes, suggest environment stability of dyes in various solvent polarity. AIEE activity with good emission at solid-state make the dyes suitable candidature for solid state OLED's application. Further Dynamic Light Scattering (DLS) studies of dye 1 validate reverse correlation of emission behavior of nanoaggregate formed at high water fraction of THF–H₂O mixture with its particle size. The good thermal stability of dyes reflected by decomposition temperature i.e., 221°C–357°C (292°C–372°C) for 5(10)% weight loss. The LUMO (−3.68 to −3.83 eV) of derivatives are lower than LUMO of reported n-type materials (−3.0 to −3.30 eV). Thus, photophysical with AIEE activity and electrochemical properties obtained for dyes signify suitability of it in organic electronics.