Determination of the difference in the zero point energies of gauche- and trans-N 2F 4 from the equilibrium constant of NF 2 radical dimerization

Abstract

Experimental equilibrium constants of the dimerization process 2 NF 2(g) = N 2F 4(g) were used for the determination of the energy difference in the ground states of gauche- and trans-N 2F 4(g) molecules. The equilibrium studied was taken as a result of two partial processes, viz. 2 NF 2(g) = trans-N 2F 4(g) and 2 NF 2(g) = gauche-N 2F 4(g). The treatment used represents a generalization of the “third law analysis”, leading to a non-linear problem which was solved by the “variable metric method” iteration technique. After treatment of all the experimental data available in the literature the value 2.39 kJ.mol -1 was found. The applicability of quantum chemistry methods for this kind of calculation is discussed.