Kinetics of the reaction of NO₂ with a macrocyclic nickel complex

The kinetics of the reaction between NO₂ and ([14]aneN₄)Ni²⁺ were determined by laser flash photolysis. The NO₂ was generated in two independent reactions, one of which is based on the photochemistry of (NH₃)₅CoNO₂²⁺, and the other on the photochemistry of HNO₂/NO₂⁻. The results from both sets of experiments yielded a consistent value for the rate constant, k₁ = 1.2 × 10⁸ M⁻¹ s⁻¹ in aqueous solutions at pH 1–4. There was no evidence for the reverse reaction. NO₂ reacts with Fe_aq²⁺ more slowly, k_Fe ∼ 2 × 10⁵ M⁻¹ s⁻¹. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 278–281, 2002