Blue and green light emitting polyarylpyrazolines luminogens containing anthracene and thiophene units

Abstract

Polyarylpyrazolines are synthesized by Claisen-Schmidt condensation followed by Suzuki cross-coupling polycondensation. Polyarylpyrazolines (PAPF, PTPF) containing various aryl substituents emit with blue and green light makes them suitable for optoelectronics applications. Photophysical and electrochemical properties are changed by varying monomeric units in the polymer backbone. The polymers are designed to serve as difunctional charge carriers useful as both hole and electron transport materials in PLEDs and achieved by modulating the energy levels through changing segments and their emissive nature turn them as tri-functional polymers. The photophysical properties such as absorption and emission along with lifetime analysis were studied. The polymers are soluble in many organic solvents, hence solvatochromism explored and explained in nonpolar to polar solvents along with Lippert-Mataga plots. It is observed that LUMO level is brought down and imparts improved electron injection and better transport ability. One of fascinating characteristics of these polymers is trouble-free synthetic procedure, nontoxic and tuning emission properties. This approach yields a toolbox of molecules to construct π-conjugated polymers to explore better organic light emitting diode performance.