Matrix Infrared Spectroscopy and Quantum-Chemical Calculations for the Coinage-Metal Fluorides: Comparisons of ArAuF, NeAuF, and Molecules MF2 and MF3

The reactions of laser‐ablated Au, Ag, and Cu atoms with F2 in excess argon and neon gave new absorptions in the MF stretching region of their IR spectra, which were assigned to metal‐fluoride species. For gold, a NgAuF bond was identified in mixed neon/argon samples. However, this bonding was much weaker with AgF and CuF. Molecules MF2 and MF3 (M=Au, Ag, Cu) were identified from the isotopic distribution of the Cu and Ag atoms, comparison of the frequencies for three metal fluorides, and theoretical frequency calculations. The AuF5 molecule was characterized by its strongest stretching mode and theoretical frequency calculations. Additional evidence was observed for the formation of the Au2F6 molecule. To coin a phrase: Experiments in solid neon and argon under cryogenic conditions led to the formation and characterization of MF2 and MF3 molecules (M=Au, Ag, Cu), NgAuF complexes (Ng=Ne, Ar), and AuF5 (see figure), whilst also providing evidence for the formation of Au2F6. IR spectra were in excellent agreement with state‐of‐the‐art quantum‐chemical calculations.