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Titolo:
Complexation thermodynamics of p-tert-butylcalix[4]arene derivatives with light lanthanoid nitrates in acetonitrile
Autore:
Liu, Y; Li, S; Bai, XP; Wada, T; Inoue, Y;
Indirizzi:
Nankai Univ, Dept Chem, Tianjin 300071, Peoples R China Nankai Univ Tianjin Peoples R China 300071 anjin 300071, Peoples R China ERATO, Inoue Photochirogenesis Project, JST, Toyonaka, Osaka 5650085, Japan ERATO Toyonaka Osaka Japan 5650085 t, JST, Toyonaka, Osaka 5650085, Japan Osaka Univ, Dept Mol Chem, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 ol Chem, Suita, Osaka 5650871, Japan
Titolo Testata:
SUPRAMOLECULAR CHEMISTRY
fascicolo: 4, volume: 13, anno: 2001,
pagine: 529 - 537
SICI:
1061-0278(2001)13:4<529:CTOPDW>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
ENTHALPY-ENTROPY COMPENSATION; CALORIMETRIC TITRATION; MOLECULAR RECOGNITION; INCLUSION COMPLEXATION; CYCLODEXTRINS; CHEMISTRY;
Keywords:
calix[4]arene derivatives; calorimetric titration; complexation thermodynamics; light lanthanoid cations; ions selectivities;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
28
Recensione:
Indirizzi per estratti:
Indirizzo: Liu, Y Nankai Univ, Dept Chem, Tianjin 300071, Peoples R China Nankai Univ Tianjin Peoples R China 300071 00071, Peoples R China
Citazione:
Y. Liu et al., "Complexation thermodynamics of p-tert-butylcalix[4]arene derivatives with light lanthanoid nitrates in acetonitrile", SUPRAMOL CH, 13(4), 2001, pp. 529-537

Abstract

Calorimetric titrations have been performed for the first time in anhydrous acetonitrile at 25 degreesC to give the complex stability constant (K-s) and thermodynamic quantities for the complexation of light lanthanoid(III) nitrates (La-Gd) with 5,11,17,23-tetratert-butyl-26,28-bis(cyanomethoxy)-25,27-dihydroxy- calix[4]arene (1) and 5,11,17,23-tetra-tert-butyl-26, 28-bis(2-aminoethoxy)-25,27-dihydroxycalix[4]arene (2). X-ray crystallographic structures of I and 2 were also determined and compared. Possessing the cyanomethoxy and aminoethyl substituents, 1 and 2 displayed strikingly differentcation binding abilities and selectivity profiles with much higher Ks values for La3+ and Ce3+, which may be related to the original structures in the solid state. Thus, the binding profile for 2 showed a rapid decrease in KS with decreasing ionic diameter from La3+ to Pr3+ and then became flat up to Gd3+, while 1 gave a very flat profile which is superimposable with thatfor 2 between Pr3+-Gd3+. Thermodynamically, the complexation is driven absolutely by enthalpy which compensates the entropic loss arising from the structural freezing of the calix[4]arene derivatives upon simultaneous binding of lanthanoid ion by the phenolic oxygen and acetonitrile molecule in thecavity. The general validity and the meaning of the compensative enthalpy-entropy relationship observed are discussed.

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Documento generato il 15/07/20 alle ore 21:36:34