ISSN:
1573-1111
Keywords:
Enantiomeric recognition
;
pyridino-18-crown-6 type ligands
;
primary alkylammonium salts
;
equilibrium constant (K)
;
enthalpy change (ΔH)
;
entropy change (ΔS)
;
NMR
;
titration calorimetry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Equilibrium constant (K), enthalpy change (ΔH), and entropy change (ΔS) values were determined for the interactions of a series of chiral pyridino-18-crown-6 type ligands with enantiomers of several primary alkylammonium salts in various solvents. Good enantiomeric recognition in terms of Δ logK was observed in many systems with Δ logK values greater than 0.4. The extent of enantiomeric recognition and the stabilities of the chiral crown ether-ammonium salt complexes were found to depend on the rigidity of the macrocyclic frame of the ligand, the type and arrangement of the donor atoms on the ligand, the bulkiness of the substituents on the ligand's chiral centers, the location of the chiral centers on the ligand, and the solvent. The effects of these factors on the extent of enantiomeric recognition and on the stabilities of the complexes were examined for the systems studied.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00711856
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