Experimental evidence for the molecular molybdenum fluorides MoF to MoF6: a matrix isolation and DFT investigation

Abstract

All of the molecular molybdenum fluorides, MoF to MoF₆, have been synthesised from the reaction of thermally evaporated molybdenum atoms with fluorine molecules and atoms, trapped in argon matrices, and characterised by matrix isolation IR spectroscopy in conjunction with DFT calculations. This includes the first spectroscopic characterisation of MoF and MoF₂, the latter of which is very bent with a bond angle of ca. 133°, the reassignment of the IR spectral data for trigonal planar MoF₃, the observation of tetrahedral MoF₄, the assignment of new features to MoF₅ which displays a Jahn-Teller distorted trigonal bipyramidal structure, and octahedral MoF₆. When the reaction of fluorine molecules and heated molybdenum is allowed to take place, MoF₆, MoF₄ and (MoF₅)₃ are observed.