Infrared Spectroscopic and Theoretical Studies on the OMF₂ and OMF (M = Cr, Mo, W) Molecules in Solid Argon

Abstract

Group 6 metal oxide fluoride molecules in the form of OMF and OMF (M = Cr, Mo, W) were prepared via the reactions of laser-ablated metal atoms and OF in excess argon. Product identifications were performed by using infrared spectroscopy, OF samples, and electronic structure calculations. Reactions of group 6 metal atoms and OF resulted in the formation of ternary OCrF, OMoF, and OWF molecules with C symmetry in which the tetravalent metal center is coordinated by one oxygen and two fluorine atoms. Both OCrF and OMoF are computed to possess triplet ground states, and a closed shell singlet is the ground state for OWF. Triatomic OCrF, OMoF, and OWF molecules were also observed during sample deposition. All three molecules were computed to have a bent geometry and quartet ground state. A bonding analysis showed that the OMF molecules have highly ionic M-F bonds. OCrF and OMoF have an M-O double bond composed of a σ bond and a π bond. OWF has an M-O triple bond consisting of a σ bond, a π bond, and a highly delocalized O lone pair forming the other π bond. The M-O bonds in the OMF compounds have triple-bond character for all three metals.

Infrared Spectroscopic and Theoretical Studies of the 3d Transition Metal Oxyfluoride Molecules

“…The OF free radical absorbing at 1028.1 cm –1 is the major metal-independent species formed during codeposition of OF 2 and laser-ablated metal atoms (V, Mn, Fe, Co, and Ni), , as observed in other reactions with metal atoms and laser plume photolysis of OF 2 . − Its infrared intensity varied as the metal and laser energy were changed. The OF absorption increased upon λ > 220 nm irradiation and decreased when the sample was annealed.…”

“…This matrix reaction route is significantly more convenient for making simple metal oxyfluoride molecules as compared to the direct evaporation of bulk materials synthesized by high-temperature reactions of solid state oxides and fluorides. Molecules in the forms of OMF 2 and OMF were the major products from the reactions of metal atoms and OF 2 . − Multiple M–O bonds with trivalent metal centers are common for the known OMF molecules, − except for OHgF which contains Hg­(II) and radical oxygen forming a single Hg–O bond . The known structures of OMF 2 molecules are more diverse depending on the nature of the metal atoms.…”

“…The known structures of OMF 2 molecules are more diverse depending on the nature of the metal atoms. The OMF 2 molecules for M = U, Th, and group 4 and 6 metal atoms have been characterized to have terminal M–O bonds with the metal centers in the +IV oxidation state. ,, The radical character on the oxygen was identified for group 3 OMF 2 molecules where the trivalent metal center is coordinated by two fluorine atoms and one oxygen radical, , as well as for the group 11 metals . For the lanthanide oxyfluoride molecules, the oxidation state is +IV for Ce and mixed +III/IV for Pr and Tb.…”

Magnetic Nanofibers: Unique Properties, Fabrication Techniques, and Emerging Applications

“…Wang et al [110] used a simple electrospinning method to encapsulate Ni 3 Sn 2 nanocrystals in CNFs to form NiSn/CNFs nanocomposite fibers, whose wave absorption performance was better than pure CNFs. When the Ni 3 Sn 2 load was 52.26 wt %, the maximum reflection loss (RL) of 39.81 dB was attained at 7.36 GHz (Figure 17).…”

Metal Oxo-Fluoride Molecules OnMF2 (M = Mn and Fe; n = 1–4) and O2MnF: Matrix Infrared Spectra and Quantum Chemistry

“…Many MO n species have been described in the literature, and a list of citations is provided in the Supporting Information, § S12. OMF 1,2 species were the major products from these reactions, and they have been identified through matrix infrared spectroscopy in solid argon supported by quantum chemical computations. − The permanganyl fluoride molecule, MnO 3 F, is a unique example of a molecular metal oxo-fluoride with a high formal OS of +VII at the metal center. , It is accessible under ambient conditions and has been prepared, isolated, and identified at the early stages, by various groups.…”