The photoluminescence and electroluminescence behaviors of four types of pyrazoline compounds of different structures dissolved in solution or composed as a dopping dye in the EL device have been studied in this work. Results indicated that the non-cyclic hydrazone compound containing the same conjugated moiety as in pyrazoline is unable to emit strong fluorescence either in solution or in solid film. But, for the pyrazoline compound very strong luminescence can be observed when it was measured in both conditions described above. The pyrazoline compounds with phenyl group at 5-position possess excellent property of film formation due to the difficulty in crystallization. On the contrary, the pyrazoline compound without phenyl group at 5-position is unadaptable to preparing EL device, because the layer contained those compounds collapse rapidly due to crystallization.

Key words: PYRAZOLINE P, PHOTOCHROMISM, ELECTROLUMINESCENCE, LUMINESCENT MATERIALS