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).