The Kinetics of Ferrocene Volatilisation from an Ionic Liquid

The volatilisation of ferrocene (Fc), dissolved in the ionic liquid N‐butyl‐N‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr][NTf2], to the gas phase has been indirectly monitored by cyclic voltammetry and chronoamperometry. Simulation of the observed trends in concentration with time using a simple model allowed quantification of the process. Volatilisation of dissolved Fc under flowing wet and dry dinitrogen gas (N2) was found to be kinetically limited with a rate constant in the region of 2×10−7 cm s−1. The activation energy of diffusion for Fc was found to be 28.2±0.7 kJ mol−1, while the activation energy of volatilisation of Fc from [C4mpyrr][NTf2] to dry N2 was found to be 85±2 kJ mol−1. Volatile solutes in non‐volatile liquids: The volatilization of ferrocene is studied in detail in the room‐temperature ionic liquid N‐butyl‐N‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr][NTf2] in a specially designed T‐cell (see picture). Ferrocene is removed by evaporation under a flow of either dry or wet nitrogen gas in a kinetically limited process with an activation energy of 85 (±2) kJ mol−1.