Diphenylthienylamine-Based Star-Shaped Molecules for Electroluminescence Applications

Star-shaped compounds containing a triphenylamine as the central core and three diphenylthienylamines (NAr1Ar2(th):  3a, Ar1 = Ar2 = Ph; 3b, Ar1 = Ph and Ar2 = 3-tolyl; 3c, Ar1 = Ph and Ar2 = 1-naphthyl; 3d, NAr1Ar2 = carbazolyl) as the peripheral functional groups have been synthesized and characterized. These compounds exhibit four successive reversible one-electron redox processes except for 3d in which only two one-electron reversible oxidation waves are observed. The compounds 3a−d can be used as hole transport materials, and electroluminescent devices ITO/3/Alq [tris(8-quinolinolato)aluminum]/Mg:Ag emit green light characteristic of Alq. The device ITO/3d/BCP (bathocuproine)/Alq/Mg:Ag is blue emitting, in which 3d is the luminophore.