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

A novel pyrazoline derivative, 3-(4-methoxyphenyl)-5-[4-(1,1-dimethylethylp henyl)]-4,5-dihydro-1-phenyl 1-H-Pyrazole (P-3) was designed and synthesize d. Its structure was elucidated by IR, H-1 NMR, MS, UV and elementary analy sis. It had hole-transporting ability, good film-formation, and excellent P L property. The device with a structure of ITO/PVK/P-3/Al could emit blue l ight (451 nm) and the turn-on voltage was 25 V. Its EL spectrum was almost identical with the PL spectrum of P-3. The maximum luminance of 200 cd m(-2 ) was achieved at 29 V. Another device of ITO/PVK/P-3/Al could emit blue li ght with emission peak of 431 nm. The emission was resulting from P-3 too. Both of the two devices showed good (electroluminescence) EL properties, an d P-3 was considered as a kind of blue OELM with high performance. (C) 2000 Elsevier Science S.A. All rights reserved.