The crystal structure of the nonclassical carbonyl [Au(CO)₂][UF₆] is determined by single-crystal X-ray diffraction. The ν(CO) vibration is observed at 2250 cm⁻¹ in the Raman spectrum. Quantum-chemical calculations with the PBE0 hybrid density functional theory method for the solid state and the [Au(CO)₂]⁺ cation in the gas phase are carried out.

The oxidation of Au powder with UF₆ in anhydrous hydrogen fluoride (aHF) under a CO atmosphere yields the previously reported nonclassical carbonyl [Au(CO)₂][UF₆], with AuC bond lengths of 1.971(10) and 1.973(10) Å and CO bond lengths of 1.146(15) and 1.088(13) Å. Its composition is now proven by the determination of its crystal structure and powder X-ray diffraction on the bulk phase. A Raman spectrum is successfully recorded and the CO vibration is observed at 2250 cm⁻¹. The nonclassical carbonyl compound [Au(CO)₂][UF₆] is synthesized by reacting Au powder, CO, and UF₆ in aHF. Its crystal structure is determined by single-crystal X-ray diffraction for the first time. Quantum-chemical calculations with the PBE0 hybrid density functional theory method (DFT-PBE0) for the crystal structure of [Au(CO)₂][UF₆] and the [Au(CO)₂]⁺ cation in the gas phase are carried out to allow for a comparison and assignment of the Raman bands.