Calix[4]Arenes Appended with Thioamide Moieties as Powerful Tool for Heavy Metals Recognition

Abstract

Selectivity of new thioamide derivatives was assessed using those ligands as sensor materials in ion-selective membrane electrodes and tested towards Pb2+ - selectivity. The influence of the nature of the thioamide function (linear, branched or cyclic substituents) on their ionophoric properties was investigated. Electrodes based on cyclic thioamide moieties are promising analytical tools for monitoring Pb2+ concentration in natural and drinking waters.

Directing the Cation Recognition Ability of Calix[4]arenes toward Asymmetric Phase‐Transfer Catalysis

“…Monohydroxy‐calixarene‐triamide 3 (Figure ) was obtained by applying the procedure reported in Scheme a. Known calix[4]arene‐tricarboxylic acid 9 was converted into the corresponding acyl chloride and then coupled with ( S )‐α‐methylbenzylamine to give 3 in 20 % yield, which was characterized by HRMS ESI(+), and 1 H and 13 C NMR spectroscopy…”

“…Compound 3: Oxalyl chloride (0.88 mL, 10 mmol) was slowly added to a stirred solution of 9 (0.22 g, 0.27 mmol) in dry CHCl 3 (10 mL) at 0 °C. The reaction mixture was heated to reflux under nitrogen for 15 h, then cooled to room temperature, and the solvent was removed under reduced pressure to give a dark solid.…”

Preparation and Properties of Three Plasticiser-Free Novel Di-benzo-18-Crown-6 Aldimine-Derived Lead(II) Ion-Selective Electrodes

“…Such features of ISEs are generally afforded by the application of an appropriate Ion-selective Membrane (ISM), hence, it is critical that fundamental knowledge of the interactions between the analyte and the ISM is established if high-quality pre-planned ISEs are to be prepared. These membranes are usually derived from molecular systems such as cryptands, thia-crowns, crown ethers and even pincer-type systems [9,[11][12][13] which are all capable of forming strong coordination bonds or Host-guest complexes with various metal ions. However, oxo-crown systems are of particular interest since they are known to be highly stable and are generally inert.…”