TQC was synthesized as previously reported. A mixture of sodium rhodizonate (0.70 g, 3.27 mmol) and 2,3-diaminophenazine (1.58 g, 7.52 mmol) was added to 50 mL of deoxygenated glacial acetic acid and heated at 120 °C for 48 h under inert atmosphere (Figure ). Upon cooling to room temperature, the solid was filtered and washed with glacial acetic acid, acetone, ethanol, and water. The product was additionally purified using 24 h Soxhlet extraction with ethanol. Obtained product was dried at 80 °C overnight yielding 1.66 g of TQC as a black powder in 98% yield (yield is based on the formation of pure catechol TQC).