Investigation of Molecular Alkali Tetrafluorido Aurates by Matrix-Isolation Spectroscopy.

Molecular alkali tetrafluorido aurate ion pairs M[AuF4 ] (M=K, Rb, Cs) are produced by co-deposition of IR laser-ablated AuF3 and MF in solid neon under cryogenic conditions. This method also yields molecular AuF3 and its dimer Au2 F6 . The products are characterized by their Au-F stretching bands and high-level quantum-chemical calculations at the CCSD(T)/triple-ζ level of theory. Structural changes in AuF4 - associated with the coordination of the anion to different alkali cations are proven spectroscopically and discussed.