Polypeptide Complexes of Silver(III)
Document Type
Article
Date of Original Version
2-1-1984
Abstract
Trivalent silver complexes of triglycine (G3) and tetraglycine (G4) have been prepared by direct reaction of the ligand with Ag(OH)4− in aqueous alkali media. The multistep formation reaction of AgIIIG4 is accompanied by a silver ion catalyzed path and a competing redox path. These complexes have characteristic spectra and, except for the method of preparation, are strikingly similar to the analogous Cu(III) system studied by Margerum and co-workers. The region of maximum stability (kd ∼7 × 10−3 s−1 for AgIIIG4) is at pH 5–10. The pKa for the interconversion of AgIII(H−3G4)− and AgIII(H−4G4)2− is about 12.5. Above pH 10 both species decompose mainly by a path involving abstraction of a methylenic proton by OH− followed by reduction of the metal to Ag1. The net activation energy for AgIIIG4 decomposition is about 16 kcal/mol. AgIIIG3 is considerably less stable than the tetraglycine complex at lower pH. © 1984, American Chemical Society. All rights reserved.
Publication Title, e.g., Journal
Journal of the American Chemical Society
Volume
106
Issue
4
Citation/Publisher Attribution
Kirschenbaum, Louis J., and James D. Rush. "Polypeptide Complexes of Silver(III)." Journal of the American Chemical Society 106, 4 (1984). doi: 10.1021/ja00316a032.