8(E)-4-[{2-(2,4-dinitrophenyl)hydrazono}benzene-1,3-diol] as a solvatochromic Schiff base and chromogenic signaling of water content by its deprotonated form in acetonitrile

Abstract

A simple, cost effective Schiff base (E)-4-[{2-(2,4-dinitrophenyl)hydrazono}benzene-1,3-diol] (DBH) is synthesized and characterized by various physico-chemical and spectroscopic tools along with single crystal X-ray crystallography. This is the first report which describes its solvatochromism in solution and the signaling behavior of deprotonated DBH for the determination of water content in acetonitrile through UV-visible absorption spectra. Addition of acetate ions in acetonitrile solution of DBH results in the formation of deprotonated DBH. The effect of water content on the formation of deprotonated DBH is utilized in signaling. The deprotonated DBH exhibits a pronounced chromogenic signaling behavior that can be detected by the naked eye in response to the changes in water content in acetonitrile. Prominent color changes are observed up to 2% water content in acetonitrile and limit of detection (LOD) of the deprotonated DBH for determination of the water content in acetonitrile is calculated as 0.012%.