Detection of Oxidized Ferrocenes by LC-MS with Electrospray Ionization Using Picric Acid as the Counter Ion

Abstract

Ferrocene is an organometallic compound that readily undergoes oxidation in atmosphere under acidic conditions. However, because of its diamagnetic nature, ferrocene does not lend itself to structural analysis by nuclear magnetic resonance (NMR) spectroscopy. In this work, the oxidation of ferrocene and several of its derivatives were analyzed by liquid chromatography-mass spectrometry (LC-MS). An electrospray ionization (ESI) source was used, with picrate serving as the counter ion. This method is particularly effective for studying oxidation of ferrocenes because their reactivity toward oxygen under ambient conditions is low.