Synthesis, Thermal and Luminescence Properties of Ortho-Terphenyl Derivatives with 1,3,4-Oxadiazole Moiety

Abstract

A series of compounds and two polymers, all consisting of o-terphenyl and 1,3,4-oxadiazole units, were synthesized. They were characterized by GC, FT/IR, NMR, elemental analysis, viscometry, DSC, POM, TGA, and absorption and emission spectrometry. In general, by introducing an o-phenyl central core to 2,5-diphenyl-1,3,4-oxadiazole backbone, the processablility of these materials was improved while maintaining a blue-light-emitting capability. The CIE coordinates of compounds with p-chloro, methoxy and t-butyl groups in EL devices were found to be (0.19, 0.16), (0.17, 0.13) and (0.18, 0.13), respectively, i.e., in the deep-blue region. Also, amorphous polymer with a m-phenylene unit, which shows good solubility in common organic solvents and excellent thermal stability, emits indigo-light at 415 nm on photoexcitation.