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Titolo:
Hydrogen-bonded complexes of carboxylate anions and dextrins in an aproticpolar solvent
Autore:
Kano, K; Tanaka, N; Negi, S;
Indirizzi:
Doshisha Univ, Fac Engn, Dept Mol Sci & Technol, Kyoto 6100321, Japan Doshisha Univ Kyoto Japan 6100321 ol Sci & Technol, Kyoto 6100321, Japan
Titolo Testata:
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
fascicolo: 19, , anno: 2001,
pagine: 3689 - 3694
SICI:
1434-193X(200110):19<3689:HCOCAA>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUCLEIC-ACID BASES; MOLECULAR RECOGNITION; INCLUSION COMPLEXES; CHIRAL RECOGNITION; BETA-CYCLODEXTRIN; CHAIN-LENGTH; WATER; BINDING; DERIVATIVES; RECEPTORS;
Keywords:
cyclodextrins; hydrogen bonds; NMR spectroscopy; oligosaccharides; solvent effects;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Kano, K Doshisha Univ, Fac Engn, Dept Mol Sci & Technol, Kyoto 6100321, Japan Doshisha Univ Kyoto Japan 6100321 Technol, Kyoto 6100321, Japan
Citazione:
K. Kano et al., "Hydrogen-bonded complexes of carboxylate anions and dextrins in an aproticpolar solvent", EUR J ORG C, (19), 2001, pp. 3689-3694

Abstract

Complexation of p-methylbenzoate (p-CH3C6H4CO2-) and alkanoate anions (CnCO2-) with cyclodextrins (CDs) and acyclic dextrins (Gas) through hydrogen bonding in an aprotic polar solvent, [D-6]DMSO, has been studied by means ofH-1 NMR spectroscopy. Although undissociated p-methylbenzoic acid, p-CH3C6H4CO2H, does not interact with dextrins, p-CH3C6H4CO2- binds through hydrogen-bonding interactions with fairly large binding constants (K) both to native CDs such as alpha-, beta-, and gamma -CDs and to Gns. Similar complexation was observed with CnCO2- anions. The K values are related to the basicity of the carboxylate anions. H-1 NMR spectroscopy shows that the CO2- group of the guest interacts with the secondary OH groups at the vicinal 2- and3- positions of the dextrins, while the primary OH groups do not participate at all. Formation of the hydrogen-bonded complex of beta -CD and p-CH3C6H4CO2 is an entropically favorable process. Addition of a small amount of D2O suppresses the formation of the hydrogen-bonded complexes, suggesting that hydrogen-bonding interactions between simple hosts possessing dense OH groups as hydrogen-bond donors and guests with CO2 groups as hydrogen-bond acceptors hardly occur in aqueous solution.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 20:49:26