The exchange of acetonitrile on iron(II) in acetonitrile solvent. A nitrogen-14 nuclear magnetic resonance study

Abstract

A ¹⁴N n.m.r. study of the exchange reaction Fe(CH₃CN)₆²⁺ ╲ CH₃CN in CH₃CN solvent is reported. The value for k ₁ (25°C) from the rate law R = 6k₁[Fe(CH₃CN)₆²⁺] is (5.5 ± 0.8) × 10⁵ s^-1, ΔH^‡ = 9.7 ± 0.7 kcal mol^-1, ΔS^‡ = 0.3 ± 2.2 cal mol^-1 K^-1, and A/h = 5.0 × 10⁶ Hz. These data are compared with those of related systems.