kinetics of oxidation of hydroquinone by [Co3-Salen] 2 O2 complex in acetic acid media

ABSTRACT

The keaotiox of C[o] [III]-salen[2]O[2] with hydroquinone [H[2]O[2], has been studied spectrophotometrically. Spectrophotometric measurements show that an intermediate [Co[III] - salen[+], [H[2]O[2], complex is formed, and the rate of oxidation of H[2]O is of fraction order [n = 1.5] at various equal concentrations of oxidant and reductant, and depends on both acidity, in the range of 1-8 M acetic acid, and temperature in the range of 35-60 degree. The energy of activation E = 26 Kcal mole[-1] and the entropy of activation Delta S=-16.65 cal-deg.[-1] mole[-1]. This reaction is found to be first order at various concentration of Co [III] - salen [2]O[2] complex and excess H[2]O as given by the linear relation of log [At -A infinity], vs. time