Test paper coated with Schiff base [(N,N(/)-bis(5-nitro-salicylidene)hydrazine] receptor 1 (host) can selectively detect fluoride and acetate ions (guest) by developing yellow color which can be detected by naked-eye both in aqueous-acetonitrile solution and in solid supported test kit. UV-vis spectral analysis shows that the absorption peaks at 288 and 345 nm of receptor 1 gradually decrease its initial intensity and new red shifted absorption bands at 397 nm and 455 nm gradually appear upon addition of increasing amount of F(-) and AcO(-) ions over several tested anions such as H(2)PO(4)(-), Cl(-), Br(-), I(-), NO(3)(-), NO(2)(-), HSO(4)(-), HSO(3)(-), and ClO(4)(-) in aqueous-acetonitrile solvent. The colorimetric test results and UV-vis spectral analysis are in well agreement with (1)H NMR titration results in d(6)-DMSO solvent. The receptor 1 forms 1:2 stable complexes with F(-) and AcO(-) ions. However, similar kind of observation obtained from UV-vis titrations in presence of AcOH corresponds to 1:1 complexation ratio indicating the formation of H-bonding interaction between the receptor and anions (F(-) and AcO(-) ions). So, the observed 1:2 complexation ratio can only be explained on the basis of deprotonation (∼1 eqv.) and H-bonding (∼1 eqv.) interactions [1]. The ratiometric analysis of host-guest complexes corroborates well with the proposed theoretical model optimization at Density Functional Theory (DFT) level.
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http://dx.doi.org/10.1016/j.saa.2012.10.038 | DOI Listing |
J Fluoresc
January 2025
Department of Physics, K. Ramakrishnan College of Engineering, Samayapuram, Trichy, 621112, India.
By a simple condensation reaction, the receptor with anthraquinone moiety was synthesized and its sensing properties were explored in the anion sensing studies via colorimetric, UV-vis studies, fluorescence studies, and DFT calculations. The synthesized receptor senses both acetate and hypochlorite ions in DMSO medium. By the addition of all anions into the receptor the colour change was observed from pink to light purple colour for acetate ion and pink to light blue for hypochlorite ion.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
Designing molecular receptors that bind anions in water is a significant challenge, and an even greater difficulty lies in using these receptors to remove anions from water without resorting to the hazardous liquid-liquid extraction approach. We here demonstrate an effective and synthetically simple strategy toward these goals by exploiting ion-pair assembly of macrocycles. Our anion binding ensemble consists of an octa-chloro tetra-urea macrocyclic anion receptor (ClTU), which forms water-dispersible aggregates, and a tetra-cationic fluorescent dye 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP4), which provides Coulombic stabilization and fluorescence reporting of anion binding in an ion-pair assembly.
View Article and Find Full Text PDFMolecules
December 2024
Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA.
Recently, 4-(pyrrol-1-yl)pyridine has been found to act as a supramolecular chemodosimeter, sensing nitrite ions in an aqueous solution with naked eye detection and a low limit of detection of 0.330 ppm. This work explores the anion-sensing properties of related derivatives, 4-(2,5-dimethyl-pyrrol-1-yl)pyridine and 4-(2,4-dimethyl-pyrrol-1-yl)pyridine, and provides a comparison with the parent compound.
View Article and Find Full Text PDFNanoscale Adv
January 2025
Can Tho University 3/2 Street, Ninh Kieu Can Tho 94000 Vietnam
Acta Crystallogr C Struct Chem
November 2024
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, km 14.5 Carretera Toluca-Atlacomulco, Toluca 50200, Mexico.
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