Theoretical Validation of Reversible Acidochromism of a Cinnamaldehyde based Scaffold with Experimental Investigations

Abstract

Present study explores the reversible acidochromism displayed by cinnamaldehyde derivative-based scaffold (P1), which is highly sensitive to variations in acidity and basicity. Upon exposing to an acidic environment, the solution containing P1 undergoes a vivid colour shift from yellow to a vibrant pink-fuchsia colour due to the conversion of imine within P1 into its quinonoid form. The color change can be completely reversed by adding a basic material, demonstrating the reversible acidochromic behavior of the P1 system. Moreover, the practical application of this acidochromic property is demonstrated through the development of a test kit utilizing paper strips. This kit effectively harnesses the acidochromic nature of P1 to detect even minute quantities of acidic or basic substances in solutions. The underlying mechanisms of the acid-base detection and corresponding colorimetric shifts in response to the acid-base interactions have meticulously been explored using density functional theoretical investigations.