Matrix Infrared Spectroscopic and Theoretical Study on the Pt(SF4) and PtF2SF2 Complexes with Multiple Pt-S Bonding Characters

Abstract

The reactions of laser-ablated platinum atoms with SF4 in neon matrixes at 4 K resulted in the formation of two complexes Pt(SF4) and PtF2SF2. Their structures were identified by the specific infrared absorptions as well as isotopic frequency shifts upon 34S substitution and density functional theory calculations. The Pt(SF4) complex grew up during sample annealing, which was converted to PtF2SF2 upon λ>280 nm irradiation. Density functional theory calculations at the PBE0 level of theory show that both the PtF2SF2 and Pt(SF4) complexes possess singlet ground states. The former possesses a nonplanar Cs symmetry whereas a geometry with Pt atop SF4 is obtained for the latter. Geometric and bonding analysis reveal the presence of multiple bonding characters between Pt and S in both PtF2SF2 and Pt(SF4) complexes, but the PtF2SF2 complex exhibits a less polarized S based σ bond and more polarized Pt based π bond than Pt(SF4).