Bis[4-(N,N-di-p-toly]amino)phenyl] chalcogenides - Synthesis of novel holetransport materials containing chalcogen atom and their application to organic electroluminescence devices

The title novel hole transport materials (HTM) (1-3) have been synthesized in good yields by the modified Ullmann coupling reaction of the correspondi ng bis(4-aminophenyl) chalcogenides with D-iodotoluene in the presence of C u, K2CO3 and 18-crown-6 in o-dichlorobenzene. From the electrochemical and spectroscopic measurements, it was evaluated that the HOMO levels of these materials are nearly the same as that of TPD, the most typical hole transpo rt material, while the LUMO levels are fairly higher. Electroluminescence d evices with the layer structure ITO/HTM(50 nm) /Alq(3)(50 nm) /Al(500 nm we re fabricated by successive vapor deposition of the materials under vacuum onto an ITO-coated glass. All the devices utilizing 1-3 emitted green light from Alq(3) and showed higher luminous efficiency than the device using TP D. In particular, the highest luminance of 2298 cd/m(2) was observed for th e device of the sulfide-derivative(1).