TQC powder (0.7 g) was suspended in 150 mL of acetic acid using an ultrasonic bath. After the addition of K2Cr2O7 (5.95 g, 20.25 mmol) to the suspension the mixture was heated at 100 °C for 6 h under an inert atmosphere. Upon cooling to room temperature, the solid was filtered and washed with water, acetone, and ethanol. The material was further purified using two sequential 16 h Soxhlet extractions with water and ethanol. The obtained product was dried at 80 °C overnight yielding 0.38 g of OTQC (49 % yield based on the formation of pure dimer OTQC).