Heats of Formation of Two Isomers of Difluorodiazine

Abstract

The heats associated with the reactionN2F2(g)+83NH3(g)=2NH4F(c)43+N2(g),were observed for two mixtures containing the trans and the ``active'' isomeric forms of difluorodiazine (N2F2) in different proportions. From the observed heats of reaction of the two samples the heat of isomerization ΔH2980 of ``active'' to trans-N2F2 was found to be 3.0 kcal mole—1 with a calculated standard error of 0.3 kcal mole—1 based on four degrees of freedom. With the use of auxiliary data for NH3 and NH4F, the heats of formation ΔHf2980 were determined to be +19.4 and +16.4 kcal mole—1 for the trans and the ``active'' isomers, respectively. The bond energies in the two substances are discussed in terms of the possible molecular configurations.