Matrix Infrared Spectroscopy and Quantum‐Chemical Calculations for the Coinage‐Metal Fluorides: Comparisons of ArAuF, NeAuF, and Molecules MF 2 and MF 3

The reactions of laser‐ablated Au, Ag, and Cu atoms with F 2 in excess argon and neon gave new absorptions in the MF stretching region of their IR spectra, which were assigned to metal‐fluoride species. For gold, a NgAuF bond was identified in mixed neon/argon samples. However, this bonding was much weaker with AgF and CuF. Molecules MF 2 and MF 3 (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 AuF 5 molecule was characterized by its strongest stretching mode and theoretical frequency calculations. Additional evidence was observed for the formation of the Au 2 F 6 molecule.