Stability and Structure of Silver–l-methionine Complexes

Abstract Stability and structure of complexes between silver (I) l -methionine (L) deduced from potentiometric 1 H NMR measurements allow to assume the prevailing several protonated species. The experimental data are compatible with formation following complexes: AgL, AgL 2 , AgH L, L 3 4 . coordination sites obtained by spectra, showing that only bond methylthioether sulfur atom is responsible complex stability. system studied potentiometrically glass electrodes at 25 °C 1.00 mol·dm −3 NaClO as ionic medium. Amino acids containing few not extensively studied. In particular, -methionine, even if it most important, enantiomer their present anticarcinogenic properties, quite investigated. same conditions, protonation constants determined. one that, in moderately alkaline solution, six membered chelate rings amino nitrogen, while carboxylic groups involved. No polynuclear species high stability ratio 1:2 (silver (I)/ -methionine), involving also two hydrogen ions, predominating a wide range ion concentration suggests propose study for preparation an electrode measure deprotonated concentration.