Calix[4]Pyrrole Derivative: Recognition of Fluoride and Mercury Ions and Extracting Properties of the Receptor-Based New Material

Abstract

A calix[4]pyrrole derivative, namely, meso-tetramethyl tetrakis (4-phenoxy methyl ketone) calix[4]pyrrole, 1, was synthesized and structurally (1H NMR) and thermodynamically characterized. The complexing properties of this receptor with a wide variety of anions and cations in dipolar aprotic media (acetonitrile, propylene carbonate, and dimethyl sulfoxide) were investigated through 1H NMR and conductance studies. The former technique was used to assess whether or not complexation occurs and if so to identify the active sites of interaction of 1 with ions. The composition of the complexes was established by conductance measurements. It was found that in dipolar aprotic solvents, 1 interacts only with two polluting ions (fluoride and mercury). The complexation thermodynamics of 1 and these ions in these solvents is reported. The medium effect on the binding process involving the fluoride ion is discussed taking into account the solvation properties of reactants and the product. Complexes of moderate stability are found. Given that this is an important factor to consider for the recycling of the loaded material in extraction processes, 1 was treated with formaldehyde in basic medium leading to the production of a calix[4]pyrrole based material able to extract fluoride and mercury (II) ions from water. Thus the optimum conditions for the extraction of these ions from aqueous solutions were established. The material is easily recyclable using an organic acid. Final conclusions are given.

Turning the volume down on heavy metals using tuned diatomite. A review of diatomite and modified diatomite for the extraction of heavy metals from water

“…Depending on the nature of the receptor, these are known Table 2 Summary of data on the removal of polluting ions from water by raw and modified diatomite. to complex and discriminate very effectively between anions or cations [93][94][95][96][97][98][99][100][101][102][103]. There is abundant evidence in the literature that these receptors can be tailored in order to interact with heavy metals without removing biologically essential ions.…”

Calix[n]pyrroles as Anion and Ion-Pair Complexants

“…Ballester and co-workers have also recently reported the assembly of a calix [4]pyrrole resorcinarene hybrid into a hexameric capsule with TMA Cl [59]. Danil de Namor and co-workers have also studied the anion and ion-pair complexation properties of extended cavity calix [4]pyrroles in a series of detailed studies [60][61][62][63][64].…”

A calix[4]arene derivative and its selective interaction with drugs (clofibric acid, diclofenac and aspirin)

“…42 Aliquots were taken and analysed by UV spectrophotometry at 280 nm. The uptake capacity of 1 was determined in batch experiments using a constant amount of the receptor (0.1 g) and aqueous solutions containing different concentrations of the pharmaceutical (9.10 -5 -4.4.10 -4…”