A single-parameter activity coefficient formula for appreciable ionic strengths: extrapolated activation quantities for electron transfer rates

Abstract

The coefficient of the linear ionic strength (I) term of the Debye–Hückel equation (DH) is summarily equated to the pair-formation constant of the Bjerrum type and this together with Stead–Rosseinsky contraction of the free-ion/pair boundary gives complicated l dependences of Δ;S^‡, ΔH^‡, and ΔG^‡ in satisfactory accord with those from particular cation–cation electron-transfer rate data which are otherwise in conflict with DH, even distinguishing between the effects of ClO^–₄ and CF₃SO^–₃ as medium anions.