Lower Rim Substituted p‐tert‐Butyl‐Calix[4]arene. Part 15. Pb(II)‐Ion‐Selective Electrodes Based on p‐tert‐Butyl‐calix[4]arene Thioamides

Abstract

Tetrasubstituted p-tert-butylcalix [4]arene-thioamides (1 -5) were applied as ionophores in ion-selective membrane electrodes (ISE) and were tested towards Pb-selectivity. The selectivity coefficients of the electrodes were determined. The tertiary calix[4]thioamides (1, 2) show remarkable selectivity for Pb(II) cations when compared with respectable calix[4]amides. The electrode membranes with those ligands are stable, the Pb-characteristics are close to nernstian within a wide linear range (À log c ¼ 6 -1). Compounds 3 -5, the secondary calix[4]thioamides form less stable electrode membranes. Complex formation constants of the ligands 1, 2, 3 and 5 with Pb(II) and some most interfering ions were determined.

Electrochemical Sensors

“…The Bochenska group has demonstrated the utility of a series of lower rim substituted p-tert-butyl-calix [4]arene derivatives as cation-selective neutral carriers (8). Specifically, they employed tetra-substituted p-tert-butyl-calix [4]arene thioamides in a poly-(vinyl chloride) (PVC) matrix as Pb 2+ -selective ionophores.…”

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

“…The relationship between the ligand structure and its properties, i. e. to find out how even small structural changes can affect the properties of new ionophores, is of our great interest [3]. With this view, we present here, the studies of ionophoric properties of five calix [4]arene derivatives based on tertiary thioamides differ by the nature of subtituents: linear (ligands 1-3), branched (ligand 4) and cyclic (ligand 5) (Fig. 1).…”

“…Modified calix [4]arenes are the object of great interest for many years due to their remarkable binding ability [1,2]. Nowadays, the need of monitoring, controlling and removal of heavy metal cations such as Pb 2+ or Cd 2+ , which have toxic effects on all living organisms inspires chemists to synthesize more and more selective compounds, among them a crucial role play modified calix [4]arenes.…”

“…Modified calix [4]arenes are the object of great interest for many years due to their remarkable binding ability [1,2]. Nowadays, the need of monitoring, controlling and removal of heavy metal cations such as Pb 2+ or Cd 2+ , which have toxic effects on all living organisms inspires chemists to synthesize more and more selective compounds, among them a crucial role play modified calix [4]arenes. The relationship between the ligand structure and its properties, i. e. to find out how even small structural changes can affect the properties of new ionophores, is of our great interest [3].…”

Electrochemical Sensors

“…The Bochenska group has demonstrated the utility of a series of lower rim substituted p-tertbutyl-calix [4]arene derivatives as cation-selective neutral carriers (8). Specifically, they employed tetra-substituted p-tert-butyl-calix [4]arene thioamides in a poly(vinyl chloride) (PVC) matrix as Pb(II)-selective ionophores The optimized membrane composition consisting of PVC, calix [4]-thiomorpholide, and o-nitrophenyl octylether (o-NPOE) exhibited high selectivities ( ) over copper (Cu) 2+ , cadmium (Cd) 2+ , manganese (Mn) 2+ , Zn 2+ , Ni 2+ , and Co 2+ , and a Nernstian slope of 29.5 mV·decade −1 .…”