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Titolo:
Complexing properties of [(glycylamino)methyl]phosphinic acids towards Co2+, Ni2+, Cu2+ and Zn2+ in aqueous solutions
Autore:
Lukas, M; Kyvala, M; Hermann, P; Lukes, I; Sanna, D; Micera, G;
Indirizzi:
Charles Univ, Dept Inorgan Chem, CZ-12840 Prague 2, Czech Republic CharlesUniv Prague Czech Republic 2 , CZ-12840 Prague 2, Czech Republic CNR, Ist Applicaz Tecn Chim Avanzate Problemi Agro, I-07100 Sassari, ItalyCNR Sassari Italy I-07100 Avanzate Problemi Agro, I-07100 Sassari, Italy Univ Sassari, Dept Chem, I-07100 Sassari, Italy Univ Sassari Sassari Italy I-07100 ri, Dept Chem, I-07100 Sassari, Italy
Titolo Testata:
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS
fascicolo: 19, , anno: 2001,
pagine: 2850 - 2857
SICI:
1472-7773(20011007):19<2850:CPO[AT>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
TRANSITION-METAL COMPLEXES; COPPER(II) COMPLEXES; CRYSTAL-STRUCTURE; AMINOMETHYLPHOSPHONIC ACID; AMINOPHOSPHONIC ACIDS; PHOSPHINIC PEPTIDE; ZINC(II) COMPLEXES; ANALOGS; PHOSPHONODIPEPTIDES; DIPEPTIDES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
59
Recensione:
Indirizzi per estratti:
Indirizzo: Lukes, I Charles Univ, Dept Inorgan Chem, Hlavova 2030, CZ-12840 Prague 2,Czech Republic Charles Univ Hlavova 2030 Prague Czech Republic 2 Czech Republic
Citazione:
M. Lukas et al., "Complexing properties of [(glycylamino)methyl]phosphinic acids towards Co2+, Ni2+, Cu2+ and Zn2+ in aqueous solutions", J CHEM S DA, (19), 2001, pp. 2850-2857

Abstract

The complexing properties of the phosphinic acid analogues of glycylglycine ([(glycylamino)methyl]phosphinic acids) NH2CH2C(O)-NHCH2P(O)(R)(OH) [GlyGly(P-R)] (R = Ph, Me and tert-Bu) towards Co2+, Ni2+, Cu2+ and Zn2+ ions inaqueous solutions are investigated using potentiometry, and absorption andEPR spectroscopies. The potentiometric results indicate different properties of the Cu2+-GlyGly(P-R) systems in comparison with glycylglycine and itsphosphonic acid analogue NH2CH2C(O)-NHCH2P(O)(OH), [GlyGly(P)]. The phosphinic dipeptides GlyGly(P-R) readily form complexes with Cu2+/ligand molar ratio 1:2 exhibiting the (N-amine, N-amide)(2) coordination mode above pH 9 even in solutions with only a slight excess of the ligand. In the system with GlyGly, the Cu2+ complex is observed at pH 12-13 and a metal:ligand ratio of 1:500. The metal-induced deprotonation of the amide nitrogen and the extent of formation of the 1 : 2 complexes depend on the acidity of the phosphinic acid group which is influenced by the substituent at the phosphorus atom. The models based on potentiometry are confirmed by spectroscopic measurements. Stability constants of the phosphinic dipeptides GlyGly(P-R) withthe other metal ions are the same as for glycylglycine and, therefore, thesame binding pattern through the amine group and peptide oxygen is proposed. The presence of protonated. complexes is assumed in all the systems studied. In the protonated complexes, the peptide is bound through the phosphinic acid group whereas the amino group remains protonated.. The presence of the species in the system containing the phosphonic acid analogue of glycylglycine [GlyGly(P)] with Cu2+, which was investigated by potentiometry previously, is confirmed by EPR spectroscopy.

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Documento generato il 01/04/20 alle ore 11:31:09