Kinetics of formation of intermediates in silver ion assisted aquations

There is kinetic evidence of the formation of Co(NH₃)₅NCSAg₃]⁵⁺ in the interaction of Co(NH₃]⁵NCS]²⁺ with Ag⁺ in aqueous solution, with pseudo-first-order formation rate constant k = 0.158 s⁻¹ for the forward reaction in the following equation at 25°C and Ag⁺] in the range of 1.23–5.0 × 10⁻² mol dm⁻³ and 0.10 ionic strength (NaClO₄):

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Additionally, the formation constant, β₂, for Co(NH₃)₅NCSAg₂]⁴⁺ has been determined to be log β₂ = 4.717. For the Rh(NH₃)₅I]²⁺-Ag⁺ reaction there is evidence of an outer-sphere interaction with rate constants of k₂ = 670 dm³ mol⁻¹ s⁻¹ at 25°C and 0.10 ionic strength. This outer-sphere species undergoes further reaction to give the silver ion containing intermediates of the aquation reactions.