Inverse kinetic dependence on hydroxide in the reaction of hypochlorite with nitroethane

Abstract

In strong aqueous base, pH > 11, the catalysed chlorination of nitroethane (N) obeys the rate law, v=k[N]₀[ClO^–][OH^–]^–1. These kinetics are consistent with a rate-determining attack of either hypochlorite on the nitronic acid (A)k_A= 1·8 × 10⁸ l mol^–1 s^–1, or hypochlorous acid on nitronate (C^–)k₈≃ 1·5 × 10⁵ l mol^–1 s^–1, at 25°C. A rationale is provided for the fact that the usual second-order kinetics for deprotonation of N do not apply to this halogenation of a nitro-alkane.