Formation of the Silver Hydride Ion AgH+ upon the Reduction of Silver Ions by H· in Aqueous Solution. A Pulse Radiolysis Study

Abstract

The reaction of hydrogen atoms and of alcohol radicals with monovalent silver ions is studied in aqueous solution by means of pulse radiolysis. In acidic aqueous solutions containing silver ions and an alcohol, hydrogen atoms react with silver ions to form AgH+ with a rate constant of k=1.5 × 1010dm3mol-1s-1. This complex dissociates into free silver atoms and hydrogen ions with a first order rate constant of 2 × 107s-1. A reaction of alcohol radicals with silver ions could not be observed in aqueous solutions containing either methanol, ethanol or 2-propanol during times of up to 15ms; the rate constant would therefore have to be smaller than 1 × 104dm3mol-1s-1.