Optoelectrochemical Study of Indole‐Quinoxaline‐Based π‐Extended Donor‐Acceptor Framework: Dual Blue and Red Fluorescent, n‐Type Material

Abstract Herein, the synthesis of π‐extended Donor‐Acceptor (D–A) framework 6 H ‐indolo[2,3‐ b ]quinoxaline dyes is done using a multistep synthetic approach. Dyes are characterized using various spectroscopic techniques. The impact of modifications in the molecular structure of dyes onto their optoelectrochemical including aggregation‐induced emission (AIE) phenomenon are investigated. Absorption spectra demonstrate intramolecular charge transfer (ICT) maxima at 397–409 nm, reflecting weak D–A features in dyes. A wide range of emissions spanning from blue and red exhibited by dyes, originates from various energy states such as locally excited (LE) states, twisted intramolecular charge transfer (TICT) states, and excimer emissions. In the polar media, TICT stabilization causes a change in the excimer state of emission to TICT emission. Dyes confer their suitability for numerous optoelectronic applications due to the existence of AIE activity, positive solvatochromism, good Stokes shift, thermal stability, and comparable LUMO (−3.22 to −3.30 eV) energies with commonly used n‐type materials. Nanoaggregate formation in aqueous mixture of dye 1 validated by DLS studies. A theoretical study via the Gaussian 03 program is used to rationalize experimental photophysical and electrochemical data and show nearly comparable results.