A Review on Metal Ion Sensors Derived from Chalcone Precursor

Abstract

Disclosure of new molecular probes as chromogenic and fluorogenic cation sensors is scientifically exigent work. Recently chalcone derivatives gained more attention because of their structural variability. A suitable donor and acceptor groups separated by delocalized π-orbitals display excellent chromogenic and fluorogenic properties because of intramolecular charge transfer (ICT). These designed molecular frameworks provide the coordination sites to the incoming metal ions results in small changes in the optical properties. In a typical sensing behavior, coordination leads to a large conjugation plane with the probe resulted in hypo/hyperchromic shifts or red/blue shifts. In this review, we tried to converge the reported chalcone-derived sensors and explored the design, synthesis, metal ion sensing mechanism, and practical application of the probes. We expect that this review gives a basic outline for researchers to explore the field of chalcone-based sensors further.

Synthesis, reactions and application of chalcones: a systematic review

“…The visual simplicity, rapid reaction, selectivity, and sensitivity of fluorescent chemosensors make them distinctive in that they function as a molecular stopwatch that begins when the light is turned on and ends when it is turned off; this is usually employed to explore the molecular process. 203 Thus, it is a fascinating objective to create such molecular systems that can permit biomolecules and metal ions to be detected by the human eye. Chalcone derivatives are well-known tiny molecular sensors noted for their affordability, flexibility in structural alteration, and capacity to vary their emission properties in response to binding ions or changes in the immediate environment.…”

Chalcones: Versatile intermediates in heterocyclic synthesis

“…Chalcones have already received several patents in pharmaceutical chemistry (Figure 3) [14]. Apart from their medicinal applications, they can also be used as plant growth promotors [15], sunscreen agents [16], fluorescent scaffolds [17], metal sensors [18], corrosion inhibitors [19], and liquid crystals [20]. In addition, some chalcones also show optical properties [21] and electrochemical properties [22].…”

Benzilbis(2-hydroxyanil) – highly efficient ligand for ferric ion (Fe3+) sensing

“…Turn-on fluorescence sensors work on phenomena such as chelation, suppression of isomerization, internal charge transfer, photo-induced electron transfer and deprotonation. [9][10][11][12][13][14][15][16] Most fluorophores used for the sensing of Fe 3+ ions act as turn-off probes, due to the paramagnetic nature of the Fe 3+ ion, which quenches the fluorescence of the organic fluorophore. 17 This makes the design of turn-on fluorophores for the selective detection of Fe 3+ in the presence of other metal ions relevant and challenging.…”

“…Turn-on fluorescence sensors work on phenomena such as chelation, suppression of isomerization, internal charge transfer, photo-induced electron transfer and deprotonation. 9–16…”