Kinetics of oxidation of eleven organic and inorganic substrates by the ethylenebis(biguanide)silver(III) ion have been determined in aqueous perchlorate media. Widely different rates and mechanistic versatility were observed thereby. Depending on the nature of the reductant, inner sphere, outer sphere, or Ag⁺-catalysed reactions may be observed. The Ag⁺-catalysis may involve a Ag⁺/Ag⁰ or Ag^I/Ag^II catalytic cycle. Factors controlling the nature of the mechanistic pathways to be adopted, have been discussed. The Ag^III complex is kinetically more active than its conjugate bases towards a neutral or anionic reductant. Towards a cationic reductant, however, the conjugate bases are more active. This complex exhibits some kinetic selectivity in its reactions and could therefore be utilised in kinetic methods for estimation of benzyl alcohol and hypophosphite.

In acidic aqueous media the complex [Ag^IIILL⁻)³⁺[L = ethylenebis (bi-guanide)] reacts quantitatively with oxalic acid and bioxalate ion to produce CO₂, Ag⁺ and L. Kinetic evidence indicates preequilibrium adduct formation, but the reactions appear to be outer-sphere with these adducts (I₁ and I₂) acting as kinetic dead ends.No Ag⁺ catalysis could be detected.

The dioxo-bridged Mn^IIIMn^IV complexes [Mn^IIIMn^IV(μ-O)₂L₄]³⁺(1³⁺, L=bipy=2,2′-bipyridine; 2³⁺, L=phen=1,10-phenanthroline) can be stabilized in aqueous solutions containing excess L in the rangepH 4–6. Thus stabilized in solution, the parent complex coexists only with its aqua derivative [Mn^IIIMn^IV(μ-O)₂L₃(H₂O)₂]³⁺ (1a³⁺ for L=bipy;2a³⁺ for L=phen) in rapid equilibrium. The solutions are novel oxidants and quantitatively oxidize NO₂⁻ to NO₃⁻, S₂O₃²⁻ to S₄O₆²⁻, H₂O₂ to O₂ and N₂H₅⁺ to N₂. Simple first-order kinetics is observed except in reactions of the bipy complex with NO₂⁻, H₂O₂ and in the reaction of the phen complex with N₂H₅⁺. Reaction of the bipy complex with NO₂⁻ produces the one-electron reduced intermediate1a²⁺, while H₂O₂ gives the two-electron reduced intermediate [Mn^III(bipy)₂(OH)(H₂O)]²⁺. It is concluded that (a) the aqua complexes are kinetically more active than their parents, (b) the phen complexes react slower than the bipy-complexes, (c) Mn²⁺ has no catalytic role, but intermediate manganese complexes and radical species may act as autocatalysts, (d) outer-sphere one-electron transfer occurs generally, but H₂O₂ prefers a two-electron pathway in its reactions with the dimers, (e) nuclearity is retained until one of the manganese in the dimers is reduced to the +2 state.