Lewis Acidic Behavior of MoOF₄ towards the Alkali Metal Fluorides in Anhydrous Hydrogen Fluoride Solutions

Abstract

Previous studies performed on samples of MoOF 4 dissolved in anhydrous hydrogen fluoride (aHF) solutions have indicated the presence of the [Mo 2 O 2 F 9 ] – anion. Building upon this earlier work, MoOF 4 , and M F ( M = Li–Cs) were dissolved in aHF solutions to produce M [Mo 2 O 2 F 9 ] ( M = Li–Cs) salts. Structural analysis of the obtained compounds was performed using single‐crystal X‐ray diffraction. This study provides the first single crystal structures for the [Mo VI 2 O 2 F 9 ] – anion. Additionally, IR and Raman spectroscopy were used to characterize each salt. These spectra were compared to calculated ones for the solid‐state structure of each salt using the DFT‐PBE0 density functional method. The calculated spectra were used to give band assignments in the experimentally obtained spectra.