General procedure for the synthesis of 16,17-bis(octyloxy)anthraceno[9,1,2-cde]benzo[rst]pentafene-5,10-dione from 1-bromooctane and 16,17-dihydroxyanthraquinone violet: 1.21 g (2.48 mmol) of 16,17-dihydroxyanthraquinone violet was placed in a 100 mL round-bottomed flask, and 50 mL of N-methylpyrrolidone (NMP ), heated to 100 °C and maintained for 10 min to ensure that 16,17-dihydroxyanthrone violet was well dispersed. Subsequently, 1.00 g (7.2 mmol) of anhydrous K2CO3, 0.98 g (5.08 mmol) of 1-bromooctane, and a catalytic amount of 18-crown-6 were added to the reaction system. the reaction was maintained at 100 °C, and the reaction was terminated with continuous stirring for 8 h. The reaction temperature was maintained at 100 °C, and the reaction temperature was maintained at 100 °C for 10 min. The reaction mixture was slowly poured into 100 mL of water, stirred thoroughly and filtered, the solid was collected and dried to obtain the crude product. The crude product was dissolved with dichloromethane and filtered to remove insoluble material. The dichloromethane was removed by rotary evaporator to obtain the solid product, which was weighed after drying as 1.26 g with 72% yield. Finally, the product was further purified by silica gel column chromatography using a solvent mixture of dichloromethane and methanol at a volume ratio of 20:1 as eluent.
