Design and Synthesis of Novel Organic Luminescent Materials Based on Pyrazole Derivative

Five new materials based on pyrazole derivatives have been synthesized and characterized as organic light-emitting devices. This report presents a novel approach to combine pyrazole with aromatic hydrocarbons via methylene. The formed molecules exhibited twisted structures, which resulted in high glass transition temperatures (T-g), which ranged from 83.0 to 101.1 degrees C. They also had high optical band gaps (E-g); most of their optical band gaps are determined by the absorption edge technique as 3.43 to 3.66 eV, evaluated photophysical properties of these synthesized novel chromophores, the optical properties such as maximum absorption and emission wavelengths (lambda; nm), molar extinction coefficients (epsilon; cm(-1)center dot M-1), Stokes' shifts (Delta lambda(ST); nm), and quantum yields (phi(F)). These compounds exhibited intense absorption bonds between 230 and 350 nm, and the effect of solvent polarity on emission of these pyrazole derivatives was also studied. In addition, they showed blue fluorescence in different solvents and bathochromic shift with the increase in the solvent polarity.