Conductance study of complex formation of thallium and silver ions with several crown ethers in acetonitrile, acetone and dimethylformamide solutions

Thallium(Ⅰ)-Selective Membrane Potentiometric Sensor Based on Dibenzyldiaza-18-Crown-6

“…Interestingly, the observed trend in the sensitivity of the ion-selective electrodes tried seem to follow the order of decreased stability of the resulting 1 : 1 complexes with the macrocyclic ionophore. Although the ionic radius's of K + (1.33 Å) 12 and Tl + (1.5 Å) are suited to fit inside the cavity of DBzDA18C6 (with a radius of about 1.3-1.6 Å), 13 the stronger soft-soft interaction of the latter cation with the nitrogen groups of the ring is expected to cause a higher stability of Tl + -DBzDA18C6 in comparison with K + -DBzDA18C6 [14][15][16][17] (The stability constants for Tl + -DBzDA18C6 and K + -DBzDA18C6 are 3.51 ± 0.03 15 and 2.84 ± 0.14 17 in dimethylformamide solvent at 25 o C). The stability order of other cations with smaller and larger sizes (i.e.…”

Lead-selective poly(vinyl chloride) electrodes based on some synthesized benzo-substituted macrocyclic diamides

“…pPb = 4.44-2 and pPb = 5.44-3.16 with slopes of 22 (r 2 = 0.995) and 20.5 (r 2 = 0.996) mV decade −1 , respectively. The largely decreased efficiency of macrocycles L4 and L5 compared with L1-L3 seems to be mainly due to the existence of three benzo groups on the macrocyclic ring which results in the enhanced configuration rigidity of ligand L5 [38][39][40].…”

A Review of the Thermodynamics of Complexation of Crown Ethers With Metal Ion

“…In addition, studies of crown ether toxicity have shown that the compound is not genetically toxic, despite cytotoxicity in mammalian cells, but it is highly toxic in prokaryotes and eukaryotes [72]. Some chiral derivatives of the crowns were able to differentiate between enantiomers of optically active species, making them of specific biological interest [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]73]. For example a review, with 18 references, discussing the structure and properties of crown ethers, especially with respect to their use in medical diagnosis and therapy was reported [74].…”

“…Jabbari et al [46] in 1993 studied the complexation reactions between Ag + and Tl + and DA18C6, DC18C6, DB30C10, 18C6, DB21C7, DB24C8, DB18C6, B15C5 and 12C4 in aceto nitrile, acetone, and dimethyl formarnide at 25°C by using a conductometric technique. They determined the stability constants of the resulting 1:1 complexes and found to decrease in the ordering DA 18C6>DC18C6>DB30C10>18C6>DB21C7>DB24C8 >DB18C6>B15C5>12C4 in the case of TI + complexes and in ordering DA18C6>DC18C6>18C6>DB18C6> DB24C8>DB30ClO>B15C5>DB21C7 for Ag + complexes.…”