Electron transfer at tetrahedral cobalt(II), Part III: kinetics of copper(II) ion catalysed reduction of periodate

Abstract

The stoichiometry, kinetics and mechanisms of copper(II)-catalysed reduction of periodate ion by the dodecatung-stocobaltate(II) anion in aqueous HClO4 has been investigated. The reaction follows the empirical rate law: d[Reductant]/dt=2(a+b [H+]) [Cu11] [oxidant] [Reductant] wherea=1.47±0.07×10−4 M−2 s−1b=1.90±0.05×10−4 M−3 s−1 at 24.5±0.1°C [H+]=0.02–0.20 M and I=0.50 M (NaClO4). This is, to our knowledge, the first example of an outer-sphere reduction of periodate by a metal complex in aqueous solution.