A Room Temperature Ionic Liquid‐Based Halochromic Molecular Chameleon

Abstract Understanding the acid–base chemistry and estimation of p K a values is of paramount importance particularly decrypting the mechanistic aspects of acid‐catalyzed reaction and hydrogen production in non‐aqueous medium. This report presents a halochromic ionic liquid, CAIL for visualization of acid–base equilibria and holistic prediction of p K a values in these mediums. CAIL exhibits a reversible halochromic nature by displaying an alluring colorimetric change from yellow to pink which varies from weak to strong acid and is employed for the estimation of the p K a value of different acids varying its acidity from weak to strong in non‐aqueous solvents with the help of the overlapping indicator method. Again, the acidochromic reversible behavior of the probe CAIL via absorption UV–visible spectra associated with colorific changes is implicated in the construction of molecular logic circuits and set–reset memory devices by using acid–base as the chemical encoded input and the respective optical output. The present work arouses a new custom for the development of numerous ionic liquid‐based acidochromic reversible probes and their application for the construction of optical–chemical logic circuits and the estimation of dissociation constant value of various acids as well as acidic compounds in non‐aqueous mediums.