Stable blue-emitting molecular material derived from calix[4]arene and pyrazoline: Synthesis, optical and electrochemical properties

A novel blue-emitting molecular material derived from calix[4]arene and pyrazoline was designed and synthesized. Its photophysical properties were investigated in CHCl3 solution and solid film by UV–vis and photoluminescent (PL) spectra. The maximum peaks are almost at the same positions both in UV–vis and PL spectra indicated that the grafted pyrazoline on calix[4]arene by chemical bond can help to disperse emitting pyrazoline chromophores in host material of calix[4]arene and tend to reduce the interaction of each pyrazoline molecule. Light-emitting diodes (LEDs) using this material as active layer were fabricated by a wet process. The turn-on voltage of the typical LED based on calix[4]arene-pyrazoline was about 6.6 V, and the maximum EL efficiency of the device was determined to be 1.52%. The homogeneous film based the resulting material was obtained even after keeping for three months. The primary results indicate that this novel material is a promising candidate as pure blue and stable light-emitting material for display.