Initial state and transition state effects in the mercury(II)-catalysed aquation of chlorotransition-metal complexes in binary aqueous solvent mixtures

Abstract

Rate constants are reported for the mercury(II)-catalysed equation of the [Co(NH₃)₅Cl]²⁺, trans-[Co(en)₂Cl₂]⁺, and [ReCl₆]^2– ions in water-rich methanol–, ethanol–, butyl alcohol–, ethylene glycol–, glycerol–, dioxan–, and acetonitrile–water mixtures. The observed reactivity trends are discussed and, as far as possible, analysed into initial- and transition-state components from estimated single-ion Gibbs free energies of transfer. In connection with this analysis the solubilities of the tetraphenylborates of mercury(II) and of caesium in several binary aqueous solvent mixutres are also reported.