Formation of organic nitro-compounds in flowing H2O2+ NO2+ N2+ organic vapour systems. Part 2.—H2O2+ NO2+ N2+ alkane system

Abstract

The principal products from the surface-initiated reactions in flowing mixtures of H₂O₂, NO₂, N₂ and RH, where RH = ethane, propane, n-butane and n-pentane, have been identified as the nitroalkane, alkyl nitrite and alkyl nitrate. The product yields have been measured; in the case of propane the variation of the yields with total gas pressure has also been studied.

Values have been obtained for the relative rates of primary and secondary H-atom abstraction from each alkane by OH and for the rate-constant ratios k₃/k₄ and k₅/k₆ at 298 K: R + NO₂(+ M)→ RNO₂(+ M)(3) R + NO₂(+ M)→ RONO^*(+ M)(4) RONO^*+ M → RONO + M (5) RONO^*→ RO + NO. (6).

The trends in the product yields with variation of pressure and change of R indicate that RO radicals are produced via reactions (4)–(6) rather than by a direct single-step reaction of R with NO₂.