Kinetics and Mechanism of Oxidation of Chromium(III)‐guanosine 5‐Monophosphate Complex by Periodate

The kinetics of oxidation of the chromium(III)‐guanosine 5‐monophosphate complex, [Cr III (L)(H 2 O) 4 ] 3+ (L = guanosine 5‐monophosphate) by periodate in aqueous solution to Cr VI have been studied spectrophotometrically over the 25–45 °C range. The reaction is first order with respect to both [IO 4 − ] and [Cr III ], and increases with pH over the 2.38–3.68 range. Thermodynamic activation parameters have been calculated. It is proposed that electron transfer proceeds through an inner‐sphere mechanism via coordination of IO 4 − to chromium(III).