Formation of metal oxyfluorides from specific metal reactions with oxygen difluoride: infrared spectroscopic and theoretical investigations of the OScF2 radical and OScF with terminal single and triple Sc-O bonds.
The scandium oxydifluoride free radical, OScF(2), is produced by the spontaneous, specific reaction of laser ablated Sc atoms with OF(2) in solid argon and characterized by using matrix infrared spectroscopy and theoretical calculations. The OScF(2) molecule is predicted to have C(2v) symmetry and a (2)B(2) ground state with an unpaired electron located primarily on the terminal oxygen atom, which makes it a scandium difluoride molecule coordinated by a neutral oxygen atom radical in forming the Sc-O single bond. The closed shell singlet OScF molecule with an obtuse bent geometry has a much shorter Sc-O bond of 1.682 Å than that of the OScF(2) radical (1.938 Å) on the basis of B3LYP calculations. The Sc-O bond in OScF consists of two covalent bonds and a dative bond in which the oxygen 2p(π) lone pair donates electron density into an empty Sc 3d orbital thus forming a triple oxo bond. Density functional calculations suggest it is highly exothermic for fluorine transfer from OF(2) to scandium, which favors the formation of the OScF(2) radical species as well as the OScF molecule after fluorine loss.
Department of Chemistry, University of Virginia, Charlottesville, VA 22904-4319, USA.
Yu
Y
Gong
Lester
L
Andrews
Charles W
CW
Bauschlicher