A series of 5-substituted 2-pyrazoline derivatives were synthesized and their physical properties were measured. The results indicate that the introduction of bulky groups into the pyrazoline ring increases the glass transition temperature (T_g) of the compounds and changes the luminescent mechanism of the compounds. Differential scanning calorimetry (DSC) shows that the new pyrazoline derivative, 1, 3- diphenyl-5-(9-phenanthrenyl)-2-pyrazoline (TAP7) has high T_g of 96 ℃. The electroluminescent properties of this compound were measured. It is demonstrated that TAP7 is a good hole transport material and blue electroluminescent material with high thermal stability.

Key words: PYRAZOLINE, ELECTROLUMINESCENCE, THERMAL STABILITY, LUMINESCENT MATERIALS, DSC