Adsorbed nitro-compounds and electron donor properties of magnesium oxide

Abstract

The adsorption of nitro-compounds on the surface of MgO powder has been studied by e.s.r. and reflectance spectrophotometry. Radical anions are formed on clean MgO surfaces prepared in vacuo whereas this no longer occurs if the MgO surface is contaminated with water and carbon dioxide. Several possibilities for the source of electrons in MgO are discussed and it is suggested that some of the lattice oxygen ions on the surface may act as electron donors. The nitrobenzene radical ion appears to lie flat on the surface and the e.s.r. data indicate considerable rotational freedom at 20°C.