Oxygen radical character in group 11 oxygen fluorides

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Spectroscopy
• Computational Chemistry

Background:

• Terminal oxido ligands are common in transition metal complexes.
• Group 11 terminal oxo complexes have remained elusive, presenting a significant gap in chemical understanding.

Purpose of the Study:

• To synthesize and characterize novel group 11 terminal oxo complexes.
• To investigate the reactivity of excited coinage metal atoms (Au, Ag, Cu) with oxygen difluoride (OF2).

Main Methods:

• Reaction of excited coinage metal atoms with OF2 to form hypofluorites and oxygen metal fluorides.
• Characterization using infrared (IR) matrix-isolation spectroscopy.
• Theoretical analysis using quantum-chemical calculations.

Main Results:

• Successful synthesis of OAuF and OAgF, the first characterized group 11 terminal oxo complexes.
• Identification of OAuF and OAgF as linear molecules with a triplet sigma ground state and biradical character.
• Quantum-chemical calculations revealed unpaired electrons primarily located on the oxygen ligand in antibonding O-M π* orbitals for OAuF and OAgF.
• Characterization of OM^IIIF₂ compounds with a 2B2 ground state, featuring an O-M single bond and significant spin density on the oxygen atom.

Conclusions:

• The study reports the first successful synthesis and characterization of group 11 terminal oxo complexes (OAuF, OAgF).
• The findings elucidate the electronic structure and bonding in these novel compounds, highlighting their biradical character.
• This work expands the scope of known terminal oxido complexes and provides a foundation for future research in coinage metal oxido chemistry.