Study of complex formation between 18-crown-6 and Pb2+, Tl+ and Cd2+ cations in binary aqueous/non-aqueous solvents using polarographic techniques (DPP and SWP)

Authors
Rounaghi, G Chamsaz, M Nezhadali, A
Citation
G. Rounaghi et al., Study of complex formation between 18-crown-6 and Pb2+, Tl+ and Cd2+ cations in binary aqueous/non-aqueous solvents using polarographic techniques (DPP and SWP), J INCL P MA, 38(1-4), 2000, pp. 153-161
Citations number
34
Categorie Soggetti
Chemistry
Journal title
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
ISSN journal
13883127 → ACNP
Volume
38
Issue
1-4
Year of publication
2000
Pages
153 - 161
Database
ISI
SICI code
1388-3127(200012)38:1-4<153:SOCFB1>2.0.ZU;2-9
Abstract
The complexation of Pb2+, Tl+ and Cd2+ cations by 18-crown-6 was studied in water/propanol (H2O/PrOH), water/acetonitrile (H2O/AN) and water/dimethylf ormamide (H2O/DMF) binary systems at 20 degrees C using square wave polarog raphy (SWP) and differential pulse polarography (DPP). It was confirmed tha t the stoichiometry of each of the complexes formed between 18C6 and the re spective cations is 1 : 1. The formation constants of the complexes were fo und to increase with increasing concentration of the non-aqueous solvent. I n all cases, a stability order of Pb2+ > Tl+ > Cd2+ was observed. In genera l, the stabilities of individual complexes were found to decrease as the bi nary solvent mixture varied from H2O/AN to H2O/PrOH to H2O/DMF.