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

Srikala Pangannaya,Neethu Padinchare Purayil,Venu Mankad,Prafulla K Jha,Darshak R Trivedi,Shweta Dabhi,Satyam Shinde

doi:10.3762/bjoc.13.25

Abstract

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.

Highlights

The development of new organic receptors for the detection of anions is of key interest to supramolecular chemists owing to the biological and environmental importance of anions [1,2,3,4,5,6,7].The leading role of anions such as fluoride, acetate and phosphate at the physiological level in promoting tooth and bone health, metabolism and genetic transduction has been wellBeilstein J
We report the design and synthesis of two new organic receptors decorated with suitable electron-withdrawing substituents viz. a cyano and nitro functionality as signaling unit on the heterocyclic ring
UV–vis titration experiments confirmed a modulation of the donor hydrogen bond ability as a direct consequence of the different substituents attached to the aromatic ring leading to a shift of the absorption maxima during the binding process

Summary

Introduction

The development of new organic receptors for the detection of anions is of key interest to supramolecular chemists owing to the biological and environmental importance of anions [1,2,3,4,5,6,7].The leading role of anions such as fluoride, acetate and phosphate at the physiological level in promoting tooth and bone health, metabolism and genetic transduction has been wellBeilstein J. The development of new organic receptors for the detection of anions is of key interest to supramolecular chemists owing to the biological and environmental importance of anions [1,2,3,4,5,6,7]. Increasing research interest on the selective and sensitive detection of anions has enriched the field of anion receptor chemistry with a wide array of design strategies [1519]. Among the various analytical techniques, colorimetry has drawn significant attention among chemists for its rapid response rate, low cost, easy method and high selectivity [2026]. The choice of the appropriate detection technique is highly essential as it directly dictates the efficacy of the sensor

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Conclusion