Kinetics and mechanism of oxidation of chromium(III)-guanosine 5-monophosphate complex by periodate

摘要

The kinetics of oxidation of the chromium(III)-guanosine 5-monophosphate complex, [Cr-III(L)(H2O)(4)](3+) (L = guanosine 5-monophosphate) by periodate in aqueous solution to Cr-VI have been studied spectrophotometrically over the 25-45degreesC range. The reaction is first order with respect to both [IO4-] 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 IO4- to chromium(III).