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The influences of solvents (in water-cosolvent mixtures) and salts on the kinetics and thermodynamics of the inclusion of [Ru(NH3)5(4,4'-bpy)]2+ in beta-cyclodextrin (beta-CD) have been studied. Solvent effects on the kinetics can be described as a consequence of the competition of the cosolvent for the beta-CD cavity. The salt effects on the kinetics depend on the ion pairing of the anions with the [Ru(NH3)5(4,4'-bpy)]2+ complex. On the other hand, the solvent effects on the equilibrium constant depend on the stabilization of the 4,4'-bipyridine ligand in the water-cosolvent mixture relative to water. Finally, salt effects on the equilibrium constant are interpreted as a consequence of ion pairing between the anion of the salt and the inclusion complex.

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Micellar effects on the oxidation reaction of [Ru(NH3)5pz]2+ with [Co(C2O4)3]3- in the presence of different NaCl concentrations were studied. Experimental results are discussed by using an approach based on the transition-state theory. It is shown that this approach used here is better than others based on the pseudophase model, which can also be used, because the former is able to give a clear meaning to the parameters of the model. Changes in the observed reactivity are explained by a change in the degree of association of the reactant to the micelles, which depends on the surface potential of the micelles. This potential determines the strength of binding of one of the reactants ([Ru(NH3)5pz]2+) to the micellar surface.

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