ISSN:
1573-1111
Keywords:
crown ether
;
thallium and silver nitrate
;
conductivity
;
formation constant
;
enthalpy
;
entropy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The complexation reactions between Ag+ andTl+ ions with 15-crown-5 (15C5) and phenyl-aza-15-crown-5(PhA15C5) have been studied conductometrically in 90%acetonitrile-water and 50% acetonitrile - water mixed solvents attemperatures of 293, 298, 303 and 308 K. The stability constants of theresulting 1 : 1 complexes were determined, indicating that theTl+ complexes are more stable than the Ag+complexes. The enthalpy and entropy of crown complexation reactions were determined from the temperature dependence of the complexation constants.The enthalpy and entropy changes depend on solvent composition and the TΔ S0 o–ΔH0 plotshows a good linear correlation, indicating the existence of entropy –enthalpy compensation in the crown complexation reactions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007987912346
