Studies of Radiation-Induced Reactions of 2,5-Dichlorohydroquinone in Aqueous Solutions I. Reactions in the Absence of Oxygen PDF

Keywords

radiation, oxygen, 2,5-Dichlorohydroquinone

Abstract

The radiolysis of 2,5-dichlorohydroquinone (H2QCl2) at different pHs leads to no change in the system. The addition of some alcohols leads only to a small removal o H2QCl2. This was taken to indicate an efficient back reaction. The saturation of H2QCl2 with N2O leads to the formation of 2,5-dichlorobenzoquinone (QCl2). It yield is dependent on dose and it increases with pH being a maximum in the pH range 2.1- 2.8. A satisfactory agreement is obtained between G(QCl2)calc. and G(QCl2)meas. upto pH ~2.1. At higher pH, the low yields were taken to indicate a back reaction involving N2O- and semiquinone radical (HQCl2). In the presence of H2O2, QCl2 is also produced. Its yield is dependent on radiation dose, [H+], [H2O2] and [H2QCl2]. This system has indicated that, in addition to the oxidation of H2QCl2 by OH perhydroxyl radical (HO2) can also oxidize H2QCl2 and possibly HQCl2. Whatever the reaction mechansim may be, it is concluded that H2QCl2 has a strong resistance to radiation damage