Oxygen radical character in group 11 oxygen fluorides.

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.