Matrix Isolation Spectroscopic and Relativistic Quantum Chemical Study of Molecular Platinum Fluorides PtF (n=1-6) Reveals Magnetic Bistability of PtF.

Molecular platinum fluorides PtF , n=1-6, are prepared by two different routes, photo-initiated fluorine elimination from PtF embedded in solid noble-gas matrices, and the reaction of elemental fluorine with laser-ablated platinum atoms. IR spectra of the reaction products isolated in rare-gas matrices under cryogenic conditions provide, for the first time, experimental vibrational frequencies of molecular PtF , PtF and PtF . Photolysis of PtF enabled a highly efficient and almost quantitative formation of molecular PtF , whereas both PtF and PtF were formed simultaneously by subsequent UV irradiation of PtF . The vibrational spectra of these molecular platinum fluorides were assigned with the help of one- and two-component quasirelativistic DFT computation to account for scalar relativistic and spin-orbit coupling effects. Competing Jahn-Teller and spin-orbit coupling effects result in a magnetic bistability of PtF , for which a spin-triplet ( B , D ) coexists with an electronic singlet state ( A , D ) in solid neon matrices.