ISSN:
1573-1111
Keywords:
Alkali cations
;
calixarene
;
amide
;
phosphine oxide
;
complexation
;
extraction
;
transport
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The complexing, extracting and mobile carrier properties of the tetra(phosphine oxide)-calix[4]arene 1 and the hybrid diamide-di(phosphine oxide)-calix[4]arene 2 were studied. Both ligands give 1 : 1 complexes with alkali cations in THF as shown by the picrate method. 1H NMR experiments were run to follow encapsulation of sodium and potassium cations. The corresponding spectra indicate C2-symmetrical structure. The observed extraction orders of the alkali picrates were as follows K+〉Rb+〉Li+〉Cs+〉Na+ for 1 and Li+〉Na+〉K+〉Rb++ for 2. Transport kinetics was analysed by means of a model which assumes pure diffusion and which allows the evaluation of mass transfer coefficients in all systems. These coefficients and their influences on the transport rate are discussed in terms of size of the transporting species in the liquid membrane.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007975928021
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