Synthesis of regiocontrolled triarylamine-based polymer with a naphthol unit

Redox-active polytriarylamine with hydroxyl groups is a useful material for optoelectronic applications, especially in the solution-processable multilayer devices. A novel regiocontrolled triarylamine-based polymer, poly(di-5-naphthyl-2-ol)phenylamine, with 2-naphthol units was synthesized via oxidative coupling polymerization. Polymerization in tetrahydrofuran using a Cu-amine complex oxidant under O₂ atmosphere produced polymers with number-averaged molecular weights as high as 11,300 g mol⁻¹. The structure of the polymer was characterized by ¹H and ¹³C NMR spectroscopy, showing that the oxidative coupling polymerization occurred at the outer ortho position of the 2-naphthols, preserving the hydroxyl groups. The polymer exhibited good solubility in polar aprotic solvents, with a high thermal stability of 446 °C that corresponded to 5% weight loss. The UV–vis absorption of the polymer was similar to that of DNPA, indicating that the kinked-structured polymer hindered the formation of charge-transfer complexes. These results suggest promising applications of the developed polymer in optoelectronic devices.