Complexes of silver(III) with oxoanions
Date of Original Version
Silver(III) has a half-life at pH 11 of several hundred seconds in aqueous solutions in the presence of 0.1-1.0 M concentrations of certain basic oxoanions (Oxo) (phosphate, carbonate, borate, pyrophosphate, and arsenate). This compares with a lifetime of a few seconds at pH 11 in the absence of these oxoanions. UV-visible spectra and kinetic data for these solutions are interpreted as evidence for the following equilibria in the pH range 9-13. Ag(OH)4-1 + H2O ⇌ Ag(OH)3H2O + OH- (1). Ag(OH)4-1 + Oxo ⇌ Ag(OH)3Oxo + OH- (2). Ag(OH)3Oxo + H2O ⇌ Ag(OH)2(Oxo)H2O + OH- (3) Values of K3 lie in the range 10-3 < K3 <104 M for the systems studied. K2 is estimated to be ∼102 for phosphate and slightly smaller for the other systems. Ag(OH)4- undergoes an unusual reaction with pyrophosphate at pH ∼ 8 to form a novel silver(II) complex, [Ag(P2O7)2]6-, for which EPR and electronic absorption spectral parameters are reported. © 1992.
Publication Title, e.g., Journal
Rush, James D., and Louis J. Kirschenbaum. "Complexes of silver(III) with oxoanions." Polyhedron 4, 9 (1985). doi: 10.1016/S0277-5387(00)87230-7.