Synthesis and characterization of poly(triphenylamine)s with electron-withdrawing trifluoromethyl side groups for emissive and hole-transporting layer

Poly(triphenylamine)s with electron-withdrawing trifluoromethyl side groups were prepared to afford ambipolar type polymers that can be used as not only an emissive layer but also a hole-transporting layer for PLEDs. First, triphenylamine-based monomers with trifluoromethyl side group were prepared, such as N,N-diphenyl-4-(trifluoromethyl)benzeamine (3FTPA) and N,N-diphenyl-3,5-bis(trifluoromethyl)benzeamine (6FTPA). Next, they were brominated and bolorated and then utilized to prepare poly(triphenylamine)s via Suzuki coupling reaction. The resulting polymers were characterized by NMR, GC/MS, FT-IR, TGA and DSC, while optical and electrical properties were also measured by fluorescence spectroscopy, UV–vis spectroscopy, and cyclic voltammetry (CV). The polymers exhibited deep blue emission (422, 443 nm) and high Tgs (225, 209 °C).