An investigation on the influence of co-ordinated aliphatic amines on the rates of reduction of tetrachlorodiamineplatinum(IV) complexes

Abstract

The reduction reactions of trans- and/or cis-[PtCl₄(NRH₂)₂] by [Fe(η⁵-C₅H₅)₂], Nal, and [Pt(NEtH₂)₄][ClO₄]₂ in the presence of chloride ions have been kinetically investigated in methanol [R = H, Me, Et, Prⁿ, Prⁱ, Buⁿ, Buⁱ, Bu^s, Bu^t, CH₂Bu^t, CH₂Ph, or cyclo-C₆H₁₁]. The rate constants for the cis complexes are sensitive to both σ-donor ability and steric hindrance of R, according to relationships of the Taft's type: log k_red=a+ρ_I[–σ_I(R)]+ρ_S[–E_S(R)]. The rates are increased by lowering the σ-donor ability of R and by increasing its bulkiness; the trans complexes behave similarly.