Electron donating effect of amine groups on charge transfer and photophysical properties of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinolone at molecular and solid state bulk levels

Abstract

Effect of various electron donating amines, i.e., dimethylamine (DMA), diphenylamine (DPA), phenylnaphthylamine (PNA) and dinaphthylamine (DPA) at 6 position on the electronic, photophysical and charge transfer properties of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinolone (DPPQ) as a parent molecule has been explored at the molecular and solid state bulk level. The effect of substituents on absorption and emission was studied at TD-B3LYP/6-31G** level in acetonitrile. The computed emission wavelengths were being red shifted for DMA-DPPQ, DPA-DPPQ, PNA-DPPQ than that of parent molecule which might be green, yellow, orange and red light emitters. The charge transfer nature of various DPPQ derivatives has been explored on the bases of ionization potential, hole extraction potential, electron affinity, reorganization energies, transfer integrals and intrinsic mobility. The DMA substitution at position 6 of DPPQ boost up the electron transfer integrals leading to balanced charge transport for holes and electrons. Moreover, total/partial density of states and optical properties (dielectric constant, extinction coefficient refractive indices, reflectivity and conductivity) at solid state bulk scale have been explored. Different properties of interest at molecular and solid state levels revealed that 1,3-diphenyl-1H-pyrazolo[3,4-b]quinolone derivatives would be efficient materials to be used in multifunctional organic semiconductor devices.