Photochemistry of anthraquinone-2-sodium methylsulphonate in aqueous solutions

Abstract

Flash photolysis of anthraquinone-2-sodium methylsulphonate (AQMS) in aqueous solution forms a long-lived transient which decays by first-order kinetics. The rate of decay of this transient is unaffected by oxygen or the concentration of AQMS. In the presence of chloride or bromide the anthrasemiquinones, either AQMS^– or AQMSH· depending on pH, are formed by electron transfer and they decay by second-order kinetics. The electron-transfer reaction appears to take place between the triplet state of AQMS and the Cl^– or Br^– anion.