
%0 Journal Article
%A Creaser, II 
%A Lancaster, MJ 
%A Lawrance, GA 
%A Sargeson, AM 
%A Sullivan, JC 
%T Oxidation of Formatopentaamminecobalt(III) Perchlorate by Silver(II)
%J Australian Journal of Chemistry
%D 1988/09/01
%V 41
%N 9
%P 1275-1287
%K 
%R https://doi.org/10.1071/CH9881275
%U https://www.publish.csiro.au/paper/CH9881275 
%X Formatopentaamminecobalt (III) perchlorate is oxidized relatively rapidly by AgO in acid conditions (1 M H2SO4, HNO3 or HO3SCF3), with approximately 97% of the total cobalt retained in the cobalt(III) state as [Co(NH3)5(OH2)]3+ and [Co(NH3)5X]n+ (X = SO42- or NO3-). A combination of product distribution, silver(I) and silver(II) concentration dependence and 18O-labelling experiments indicate that the major pathway (97%) is oxidation of [Co(NH3)5(OCHO)]2+ directly to [(NH3)5Co(OCO)]3+ and [(NH3)5Co(O2COH)]2+ by AgIII (through the disproportionation 2AgII &#8596; AgIII + AgI ) in a relatively rapid hydride extraction. A minor path (3%) appears to involve a one-electron oxidation by AgII to the complexed radical anion [(NH3)5Co(OC?O)]2+ which then decays intramolecularly to yield CoII and CO2. In 1 M H2SO4 the cobalt(III) intermediate, [(NH3)5Co(OCO)]3+, has been shown by 18O-labelling and competition experiments to decay by dissociation into [Co(NH3)5]3+ and CO2. The pentacoordinate intermediate [Co(NH3)5]3+ immediately captures OH2 and HSO4-. 
