Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

摘要

New colorimetric receptors >R1 and >R2 with varied positional substitution of a cyano and nitro signaling unit having a hydroxy functionality as the hydrogen bond donor site have been designed, synthesized and characterized by FTIR, ¹H NMR spectroscopy and mass spectrometry. The receptors >R1 and >R2 exhibit prominent visual response for F⁻ and AcO^– ions allowing the real time analysis of these ions in aqueous media. The formation of the receptor–anion complexes has been supported by UV–vis titration studies and confirmed through binding constant calculations. The anion binding process follows a first order rate equation and the calculated rate constants reveal a higher order of reactivity for AcO⁻ ions. The ¹H NMR titration and TDDFT studies provide full support of the binding mechanism. The Hg²⁺ and F⁻ ion sensing property of receptor >R1 has been utilized to arrive at “AND” and “INHIBIT” molecular logic gate applications.