Solvent and salt effects on the kinetics of the reaction between [Ru(NH₃)₅pz]²⁺ and [Fe(CN)₅H₂O]^3–

Abstract

The kinetics of replacement of H 2 O by [Ru(NH 3 )pz] 2+ (pz = pyrazine) in [Fe(CN) 5 H 2 O] 3− have been studied in various concentrated electrolyte solutions and in various water-cosolvent mixtures, at 298 K. Salt and cosolvent effects can be rationalized taking into account specific medium effects on both the encounter complex formation process and the ligand-substitution process, once the encounter complex is formed. These effects in watercosolvent mixtures depend on the solvation of the reactants by the components of the mixture, as well as on the solvent-solvent interactions in these mixtures. Salt effects seem to be related to a primary salt effect as well as to the effect of the cations on the electronic density on the iron complex.

Formation of a Rotaxane from the End-Capping Process of a Pseudorotaxane. Effects of the Solvent

“…According to Scheme , the process of formation of the rotaxane can be interpreted as a ligand substitution reaction. Similar processes of ligand substitution were previously studied in these reaction media by us and others . In all cases, an increase of the rate constant was observed by increasing the percentage of the cosolvent in the medium for the same organic components.…”

Study of the base‐catalyzed nitrito–nitro isomerization reaction ([(NH3)5Co‐ONO]2+ → [(NH3)5Co‐NO2]2+) in mixed solvents

“…In this paper we have studied the kinetics of this reaction in some binary aqueous mixtures. The purpose of this study is to see the possibility of applying the same multiparameter equation which works well in the study of medium effects in other ligand substitution processes which follow a different mechanism 6, 13–15. In these cases, to rationalize medium effects in binary aqueous mixtures, a multiparameter regression in which A , B , and G exc (the acidity, basicity vectors, and the excess Gibss free energy of the mixture) are the solvent parameters, has been applied.…”