Computed gas-phase thermodynamics of the N 2O 2 complexes

Abstract

The thermodynamics of the gas-phase dimerizations of N 2 and O 2 has been evaluated in terms of partition functions, constructed using quantum chemical ab initio computations. Two different evaluations of the dimerization energetics have been employed and two minimum-energy structures of the dimer (a linear structure and a T shape) have been considered. In both sets, the structures co-exist, although at temperatures relevant for atmospheric conditions the T-shaped species is more populated. The isomeric interplay is reflected in an enhancement of heat capacity, especially at very low temperatures. For the dimerization equilibrium constant, an interval in which the true value should be applicable is suggested.