Electrochemical Studies of Molybdenum Hexafluoride and Related Compounds in Anhydrous Hydrogen Fluoride

Electrochemical investigations in anhydrous hydrogen fluoride on molybdenum hexafluoride and related compounds, at platinum and glassy carbon electrodes, have shown that a series of chemically reversible, one-electron redox processes occur: MoF₆ + e⁻ ⇌ MoF₆⁻ + e⁻ ⇌ MoF₆²⁻ and MoOF₄ + e⁻⇌ MoOF₄⁻. From the electrochemical data derived from this work, molybdenum hexafluoride is shown to be a stronger oxidant than tungsten hexafluoride by approximately 1 V. While the order of oxidant strengths is consistent with the previously reported chemistry of both hexafluorides, the magnitude of the difference is unexpectedly large.