Electrochromic Properties of Polyimides Prepared from Methyl Substituted Triphenylamine Moiety with Different Dianhydrides

Synthesis, characterization and electrochromic properties of polyamides having triphenylamine derivatives

“…First, 4,4 0 -dinitro-4 00 -methoxytriphenylamine was prepared from p-anisidine (2.5 g, 20.3 mmol), 4-fluoronitrobenzene (6.30 g, 44.6 mmol) and cesium fluoride (6.78 g, 44.6 mmol) dissolved in dried 100 mL DMSO, and stirred at 150°C for 24 h (Scheme 1). The reaction mixture was poured into cold water, resulting in the precipitation of an orange-colored solid, which was collected by filtration and washed with methanol [25,26]. The yield of 4,4 0 -dinitro-4 00 -methyltriphenylamine (DN-p-OCH3TPA) was 5.71 g (70 %); 1 H NMR (DMSO-d 6 In the second step, a diamine monomer was prepared from the reduction of dinitro groups using Pd-C as the reducing agent.…”

“…A mixture of 5.0 g (13.7 mmol) of DN-p-OCH3TPA, 2.52 g (38.3 mmol) of hydrazine monohydrate, 0.2 g of 10 % Pd-C, and 100 ml of ethanol was stirred at 120°C for 8 h (Scheme 1). The reaction mixture was filtered through Celite to remove the Pd-C, and the filtrate was added to 100 ml of water to obtain precipitates, which were filtered and dried [25,26]. The crude product was recrystallized from ethanol.…”