Complex formation equilibria of some dipeptides (glycyl-alanine, glycyl-lysine, alanyl-alanine, alanyl-lysine, histidyl-alanine and histidyl-lysine) with the Ni(II) ion have been studied in aqueous solution at I=0.1 mol dm−3 (KNO3) and T=25°C. Protonation and complex formation constants have been potentiometrically determined. The structure of the main complex species is discussed on the basis of thermodynamic data obtained by direct calorimetry, CD and absorption spectra. The participation of the amide nitrogen in complex formation is suggested, while no evidence supports the participation of the NH2 side group of lysine in coordination.
Nickel complexes of dipeptides: a thermodynamic and spectroscopic study
CONATO, Chiara;PULIDORI, Fernando;REMELLI, Maurizio
2001
Abstract
Complex formation equilibria of some dipeptides (glycyl-alanine, glycyl-lysine, alanyl-alanine, alanyl-lysine, histidyl-alanine and histidyl-lysine) with the Ni(II) ion have been studied in aqueous solution at I=0.1 mol dm−3 (KNO3) and T=25°C. Protonation and complex formation constants have been potentiometrically determined. The structure of the main complex species is discussed on the basis of thermodynamic data obtained by direct calorimetry, CD and absorption spectra. The participation of the amide nitrogen in complex formation is suggested, while no evidence supports the participation of the NH2 side group of lysine in coordination.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
