Complex formation of alkaline-earth cations with crown ethers and cryptands in methanol solutions
The complexation of alkaline-earth cations by different crown ethers, azacrown ethers, and cryptands has been studied in methanol solutions by means of calorimetric and potentiometric titrations. The smallest monocyclic ligands examined from 2:1 complexes (ratio of ligand to cation) with cations which are too large to fit into the ligand cavity. With the smallest cryptand, only Sr/sup 2 +/ and Ba/sup 2 +/ ions are able to form exclusive complexes. In the case of the reaction of cryptand (211) with Ca/sup 2 +/, a separate estimation of stability constants for the formation of exclusive and inclusive complexes was possible for the first time. Higher values for stability constants are found for the reaction of alkaline-earth cations with cryptands compared to the reaction with alkali ions. This increase is only caused by favorable entropic contributions.
- Research Organization:
- Univ. G-H Siegen, Siegen
- OSTI ID:
- 7005301
- Journal Information:
- J. Solution Chem.; (United States), Journal Name: J. Solution Chem.; (United States) Vol. 15:6; ISSN JSLCA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Discussion on the complexing ability of the uranyl ion with several crown ethers and cryptands in water and in propylene carbonate
Stability constants and thermodynamic data for complexes of 12-crown-4 with alkali metal and alkaline-earth cations in methanol solutions
Related Subjects
400201* -- Chemical & Physicochemical Properties
ALCOHOLS
ALKALINE EARTH METAL COMPLEXES
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPLEXES
BARIUM COMPOUNDS
BARIUM NITRATES
CALCIUM COMPOUNDS
CALCIUM NITRATES
CATIONS
CHARGED PARTICLES
COMPLEXES
DIAGRAMS
DISPERSIONS
GLYCOLS
HYDROXY COMPOUNDS
IONS
LIGANDS
METHANOL
MIXTURES
NITRATES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXYGEN COMPOUNDS
POLYETHYLENE GLYCOLS
POLYMERS
POTENTIOMETRY
QUANTITY RATIO
SILVER COMPOUNDS
SILVER NITRATES
SOLUTIONS
STRONTIUM COMPLEXES
STRONTIUM COMPOUNDS
STRONTIUM NITRATES
SYNTHESIS
TITRATION
TRANSITION ELEMENT COMPOUNDS