Novel pyrazoline derivative used as light emitter in blue organic electroluminescent devices

A novel pyrazoline derivative, 3-(4-methoxyphenyl )-5-[4-(1,1-dimethylethylphenyl)]-4,5-dihydro-1-phenyl 1-H-Pyrazole (P3) was designed and synthesized. Its structure was elucidated by IR, 1H NMR, MS, UV and elementary analysis. It had hole-transporting ability, good film-formation, and excellent PL property. The device with a structure of ITO/PVK/P3/Al could emit blue light (451 nm) and the turn-on voltage was 25 V. Its EL spectrum was almost identical with the PL spectrum of P3. The maximum luminance of 200 cd m−2 was achieved at 29 V. Another device of ITO/PVK+P3/Al could emit blue light with emission peak of 431 nm. The emission was resulting from P3 too. Both of the two devices showed good (electroluminescence) EL properties, and P3 was considered as a kind of blue OELM with high performance.