Oxygen radical character in group 11 oxygen fluorides
Lin Li, Tony Stüker, Stefanie Kieninger, Dirk Andrae, Tobias Schlöder, Yu Gong, Lester Andrews, Helmut Beckers and Sebastian Riedel – 2018
Transition metal complexes bearing terminal oxido ligands are quite common, yet group 11 terminal oxo complexes remain elusive. Here we show that excited coinage metal atoms M (M = Au, Ag, Cu) react with OF₂ to form hypofluorites FOMF and group 11 oxygen metal fluorides OMF₂, OAuF and OAgF. These compounds have been characterized by IR matrix-isolation spectroscopy in conjunction with state-of-the-art quantum-chemical calculations. The oxygen fluorides are formed by photolysis of the initially prepared hypofluorites. The linear molecules OAgF and OAuF have a ³Σ ⁻ ground state with a biradical character. Two unpaired electrons are located mainly at the oxygen ligand in antibonding O−M π* orbitals. For the ²B₂ ground state of the OMᴵᴵᴵF₂ compounds only an O−M single bond arises and a significant spin-density contribution was found at the oxygen atom as well.