Recent progress on triphenylamine materials: synthesis, properties, and applications

Triphenylamine is a propeller-like structural chromophore with a nitrogen atom center. The compound has a large steric hindrance and hyper conjugation electronic effect, which can enhance the stability of the nitrogen atomic radical. Triphenylamine materials also have a high hole mobility due to their unique free radicals nature. In this review, we started with the methods of the synthesis including traditional Ullmann, Suzuki Coupling, Heck, Wittig, Stille, and Sonogashira Reaction synthesis, and also the basic experimental and theoretical methods for the characterization of triphenylamine materials. Then, we discussed the properties of triphenylamine, including the optoelectronics, electroluminescence, and electrochromism. Finally, we reviewed the recent progress in the main applications of triphenylamine materials in the field of organic optoelectronic solar cells, electroluminescence materials, and electrochromic materials. In conclusion, this review of triphenylamine materials is a valuable resource for both theorists and experimentalists who are focus on these exciting compound materials.