The effect of free valencies on the chemical properties of azacarbons and carbons

Abstract

Carbons of high nitrogen content were prepared by charring urea-formaldehyde condensation products, and their adsorption properties studied after activation at various temperatures. The products were found to have only low basicity, which, it is suggested, is partly due to the presence of positive holes formed in the π-band during devolatilization (removal of hydrogen atoms and substituents) of the carbons. The quinone character of the carbons and their behaviour in adsorption and rubber reinforcement are also discussed in the light of this theory. It is suggested that the stabilization of devolatilized carbons, their facile adsorption of oxygen and resistance to hydrogenation, is explained by the presence in the σ-band of unshared electron pairs resulting from the formation of the π-band holes.