Highly fluorescent semiconducting pyrazoline materials for optoelectronics

Abstract An investigation has been made to synthesize small organic materials possessing longer wavelength emission in a simple manner. Three novel pyrazoline compounds were synthesized and characterized by appropriate approaches. The effect of thiophene, furan and pyridine substitution on pyrazoline skeleton was studied and explained systematically. Green, blue and violet emission was obtained with respect to different substituent groups. The fluorescence decay time and quantum yield of the synthesized materials I , II and III are found to be 3.42, 2.65, 2.83 ns and 0.83, 0.76, 0.78 respectively. The theoretical quantum calculation was used to optimize the spatial distribution of ground state geometry (HOMO) and excited state geometry (LUMO) levels of the molecules. The materials performance and bandgap energies ( E g ) of all the three compounds revealed that they belong to a semiconductor materials category.