Optical Characteristics and Structural Properties of 3-(p-Nitrophenyl)-5-phenyl-1H-pyrazole

In this study, a conjugated 3-( p -nitrophenyl)-5-phenyl-1 H -pyrazole (NPP) was synthesized using a microwave-assisted reaction. The photophysical characteristics of NPP, such as absorption, fluorescence, Stokes shift, and fluorescence quantum yield, under different solvent environments, concentrations, and pH values were studied. NPP in ethanol showed an absorption band at 316 nm. Moreover, the shape of the absorption spectrum was not affected by an increase in the concentration. Therefore, there was no aggregation formed in the ground state for all concentrations. On the other hand, the fluorescence spectrum of NPP in ethanol exhibited three distinctive bands around 411 nm, 436 nm, and 463 nm. The intensity of the fluorescence was directly proportional to the concentration even at higher concentrations. Most of the 1 H -pyrazoles are affected by the alkalinity and acidity of media. Nevertheless, NPP was not significantly affected by the acidic or alkaline media in the ground or excited states.