Synthesis and Photo-Electro Properties of Novel Star-Shaped Molecules of Triphenylamine with Terminal Groups of

Abstract: Three novel star-shaped molecules of triphenylamine with terminal groups of naphthalimide have been designed and synthesized, in which triphenylamine unit performs as the hole transporting moiety, 1,8-naphthalimide unit performs as the electron transporting and emitting moiety. The structures have been confirmed by HRMS, FT-IR, 1H NMR spectra. The temperature of the glassy state changed into the supercooled liquid state (Tg) is as high as 253~274 °C. There exists an effective singlet-singlet energy transfer due to the overlap between the absorption of naphthalimide moiety and the emission of carbazole moiety, which lowers the fluorescence quantum yields. The electrochemistry properties have been determined on Cyclic Voltammetry. Their band gaps (Eg) and ionization potentials (PI) have been calculated at 2.46~2.59 eV and 5.54~5.83 eV respectively. The results indicate that the novel compounds are good candidates not only as hole-transporting materials but also as electro-transporting materials for single-layer OLEDs