Non-linear Optical Response of Phenoxazine-based Dyes: Molecular Engineering of Thiadiazole Derivatives as π-spacers

In this article, various dyes have been quantum chemically designed which are based on A-π-D-π-A structural configuration. The main objective of this work is to study the effect of electron deficient thiadiazole derivatives as the π-spacers. The role of these π-spacers in phenoxazine-based dyes have been studied through electronic, non-linear optical (NLO) and absorption properties. The electronic structures, absorption spectra and NLO response were calculated by employing quantum chemical methods. The results reveal that the polarizability ( α ) and hyperpolarizability ( β ) remarkably increase from dye 1 to dye 5 . As compared to model of dye 1 , dyes 2-5 have shown red-shifted absorption spectra and low band gaps.