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 CHCl(3) 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. (C) 2009 Elsevier B.V. All rights reserved.