Eco-friendly preparation and testing of electroactive quinoxalines

Green manufacturing of electroactive molecules is a central pillar of innovation due to sustainability, consumer safety, and functional properties. Quinoxalines are important in biology (bacterial reactions, anticancer medicine), chemistry (manufacturing), material science, and optoelectronics (OLEDs, solar cells, batteries, SCs). This research explored eco-friendly preparation and testing of 5-electroactive quinoxalines. We utilized a vertical ultrasound-horn attached to the VCX-750 instrument to discover the green synthesis of electroactive quinoxalines. The method (45 min @RT) utilized green-solvent (CH
3
COOH) for both the synthesis and purification, leaving no harmful byproduct wastes. The purity of five different quinoxalines was confirmed through the UV-Vis spectroscopy, elemental analysis, and nuclear magnetic resonance (
1
H NMR (500 MHz) and
13
C NMR (125 MHz)). The electroactivity and electronic reversibility were investigated through voltammograms (Current-Voltage curves) that provided data showing the reversible (in-out) electron transfer. All five quinoxalines indicated a negative scan, reversible electron-transfer; therefore, these quinoxalines will be useful as the negative electrode in the charge-storage materials (Supercapacitors and flow-batteries). Based on the experimental reduction formal potential (
E
o
red
), the Qx-3 and Qx-4 are the best candidates to widen the negative potential windows, while the Qx-5 is suitable to shorten the negative potential window. The experimental results are important for green processing in chemistry, material science, and reversible electroactivity is required for the charge-storage materials.