Computational Study on Non-linear Optical and Absorption Properties of Benzothiazole based Dyes: Tunable Electron-Withdrawing Strength and Reverse Polarity

Various organic dyes possessing characteristic D-π-A-A configuration have been designed in this article. The analysis of the relation between polarity of charge transfer and the unsymmetrical nature of the benzothiazole group has been studied. The absorption spectra, electronic characteristic properties and non-linear optical responses were simulated using a quantum chemical approach. The results have indicated that the systems show higher polarizability (α) and hyperpolarizability (β) with commonly used polarity in comparison to the reverse polarity. A red-shifted absorption spectra were observed with systems having common polarities. This study illustrates the rule to design non-linear optical material with low energy charge transfer excited states and high value of oscillation.