Kinetics and mechanism of the formation and oxidation of iminodiacetato-chromium(III)‎ complex

Abstract EN

The kinetics of formation of chromium (III)-iminodiacetic acid complex has been studied spectrophotometric ally in the temperature range 35-55 °C.

The reaction is first order with respect to chromium (III) and the rate of reaction increases with increasing of pH.

The kinetics of formation obeys the rate law: Rate = kcKosc [ Crm (H20)5(OH)} 2T+ [ \DA}/( \ + S0SC[IDA]) While the kinetics of oxidation of Crln (IDA) 2 (H20)2]_by JV-bromosuccinimide (NBS) in aqueous solution to chromium(VI) were carried out and obey the following equation: D [Crv,] / d / = {k4K2 + A: 5S3^I / [H+])[CrIII(IDA)2(H20)2]"[NBS]. Thermodynamic activation parameters have been calculated.

It is proposed that electron transfer proceeds through an inner-sphere mechanism via coordination of NBS to chromium (III).