Differential Metal Ion Sensing by an Antipyrine Derivative in Aqueous and β-Cyclodextrin Media: Selectivity Tuning by β-Cyclodextrin

Abstract

β-Cyclodextrin (β-CD) is a nontoxic cyclic oligosachcharide that can encapsulate all or part of organic molecules of appropriate size and specific shape through noncovalent interaction. Herein, we report the influence of β-CD complex formation of an antipyrine derivative on its metal ion sensing behavior. In aqueous solution, the antipyrine shows a turn-on fluorescence sensing of vanadyl ion, and in cyclodextrin medium it senses aluminum ion. The compound shows an unusual fluorescence quenching on binding with β-cyclodextrin (log K SV = 2.34 ± 0.02). The differential metal ion sensing is due to the partial blocking of the chelating moiety by the cyclodextrin molecule. The structure of the antipyrine− cyclodextrin complex is optimized by two-dimensional rotating-frame Overhauser effect spectroscopy. The binding constant is determined by isothermal titration calorimetry (log K = 2.09 ± 0.004). The metal ion binding site is optimized by quanutm mechanical calculations. The lower limit of detection of vanadyl and aluminum ions, respectively, are 5 × 10 −8 and 5 × 10 −7 mol dm −3 . This is the first report of selectivity of two different cations by a chemosensor in water and in β-CD.

Aggregation-Induced Emission-Active Hydrazide-Based Probe: Selective Sensing of Al3+, HF2–, and Nitro Explosives

“…In recent times, the design of sensors (ions or small molecules) and their application in live cells for the detection of ions/molecules have received active interest from chemistry, physics, chemical engineering, electrical and electronic engineering, and many other branches. On considering the social and biological importance of Al­(III), some examples of fluorescent sensors have been reported for Al 3+ detection with the Schiff base scaffold of 4-aminoantipyrine derivatives, rhodamine B ligands, coumarinyl derivatives, benzophenone, chromone, diphenyl pyrrol derivatives, pyrazoles, quinolones, fluorenes, benzimidazoles, and so forth. Besides, a limited number of sensors exhibit aggregation-induced emission (AIE), and their emissivity, in some cases, has been influenced by Al 3+ ions .…”

Fluorescence Enhancement of Adamantane‐Modified Dyes in Aqueous Solution via Supramolecular Interaction with Methyl‐β‐cyclodextrin and Their Application in Cell Imaging

“…It was reported that the formation of intermolecular hydrogen bond was conducive to the complexation between host and guest. [20] The carbonyl oxygen atoms of 1,8-naphthalimide and the 3-OH groups of the ring provided condition for the formation of hydrogen bonds, which was verified by the optimization results of Gaussian calculations (Figure S5). In addition, 1 H NMR titration experiment was operated by fixing LDs-NPAd2 (2 mM) and M-β-CD with different molar ratios (1 : 0, 1 : 2) to investigate the host-guest interaction (Figure S6).…”

Changes in Protonation Sites of 3-Styryl Derivatives of 7-(dialkylamino)-aza-coumarin Dyes Induced by Cucurbit[7]uril

“…Recently, the importance of designing new molecular systems that facilitate the participation of heterocyclic nitrogen as ionophores for heavy metal ion recognition has been discussed ( Nagarajan et al, 2021 ). These designs can be associated with changes in the scaffold of the N -heterocyclic molecule which, using supramolecular host-guest systems, could act as a differential metal ion sensing ( Xu et al, 2010 ; Selvan et al, 2018 ), or in a synergetic binding mode ( Xu et al, 2010 ).…”