Heats of formation of C₁C₄ alkyl nitrites (RONO) and their RO‐NO bond dissociation energies

The heats of formation of C 3 and C 4 alkyl nitrites (RONO) have been determined via their heats of combustion by bomb calorimetry, thereby providing a complete set of values of ΔHº f for C 1 ‐C 4 alkyl nitrites. The experimental values are in excellent agreement with values derived from group additivity rules. For branched compounds these calculations involve corrections for gauche interactions. In these cases, the gauche interactions are reflected in the activation energies E 1 determined by recent kinetic studies, required for breaking the RO‐NO bond. equation image The heats of formation of the alkoxy radicals involved together with Δ H º f (NO) = 21.6 kcal/mole leads to the result D (RO‐NO) = 41.5 ± 1 kcal/mole. The concordance between D (thermochemical) and D (kinetic), unlike previous kinetic studies, implies that E 2 = 0 ± 1 kcal/mole.