The Heat of Dissociation of the Molecule O₄ and Sutherland's Constant for Oxygen

Abstract

THE law of interaction of two colliding molecules follows the curve shown in Fig. 1, where the mutual potential energy U of the molecules is plotted against the distance r between their nuclei. In the case of molecules with saturated bonds, U is determined by the polarisation forces and repulsive forces, the nature of which we do not propose to discuss here. When the chemical bonds are unsaturated, the ‘chemical forces’ (Austauscheffekt) also must be taken into account. In both cases the energy minimum (U₀) corresponds to a definite stationary state of the associated molecule. Such a twin will appear if the molecules lose during the collision a certain amount of their energy, for example by means of a triple collision, so that the total energy attains a negative value. The dissociation energy W of this twin is equal to −U₀ (Fig. 1).