Mechanistic insights into the recognition of Fe2+ and solvent-driven selectivity of chalcone-based receptors
Year: 2025
Type: article
Abstract: Building on recent works [Spectrochim. Acta A: Mol. Biomol. Spectrosc. 287 (2023) 122107; 303 (2023) 123129], this study offers novel insight into the supramolecular recognition of Fe 2+ by receptor R1, wherein the conventional chalcone binding strategy is extended. Density Functional Theory (DFT) is used to differentiate the complexation behavior of chalcone-based receptors (R1, R2, R3), revealing key nucleophilic centres—particularly the carbonyl and phenolic oxygen atoms—as primary coordination sites. Optimized geometries, semi-empirical tight-binding calculations, and molecular dynamics simulations highlight the crucial role of the carbonyl oxygen of R1 and demonstrate that solvent molecules actively participate in metal coordination. This leads to the proposal of a new complexation model for R1, where solvent molecules facilitate stable 1:1 host–guest complex formation. The role of non-covalent interactions (NCIs), including ion–dipole, hydrogen bonding, and van der Waals forces, is also emphasized in governing metal ion (Fe 2+ , Ni 2+ , Cu 2+ ) recognition and selectivity. Quantum mechanical electron density (ED) and reduced density gradient (RDG) analyses visualize and quantify these weak interactions, showing that Fe 2+ forms the most stable complex due to favorable coordination, unlike Ni 2+ and Cu 2+ . These theoretical predictions align with experimental results—such as pH effects, UV–Vis spectroscopy, and NMR titrations—supporting the hypothesis that solvent molecules act as auxiliary ligands. Together, these findings deepen the understanding of chalcone-based receptor design and their metal ion sensing capabilities in mixed solvent environments.
Source: Results in Chemistry
Author: Ajay Shankar
Institution: Indira Gandhi National Tribal University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,870
Awards: G5913200800, G8416571489
OpenAlex ID: W4413291585