Das Gleichgewicht F 2 S 2 O 6 ⇌ 2 FS0 3, das Absorptionsspektrum des Radikals FS0 3 und die Kinetik der thermischen Reaktion zwischen Bis-Sulfurylfluoridperoxid und Schwefeltetrafluorid

Evidences for a new Ultraviolet Absorption Band of the FSO3 Radical

An unpublished absorption band of the fluorosulphate radical, FSO3, based on earlier experiments of Schumacher and co-workers (Z. Phys. Chem. NF 42 (1964) 174) and detailed calculations of the whole FSO3 spectra based on the time-dependent (TD) generalization of the density functional theory (DFT), TD-DFT, are reported. Part of this band, that increases in intensity at wavelengths below 275 nm, has been extracted from an absorption spectrum taken from equilibrated mixtures of FSO3 with the dimer FS(O2)OO(O2)SF at 403 K. A set of thirteen exchange-correlation hybrid functionals combined with the 6-311+G(3df) basis set predict an intense absorption band centred at 256 ± 10nm in very good agreement with the experimental observations. Another significant band peaked at 184 ± 10nm was also found. The calculations reproduce accurately the position of the maximum and the experimental oscillator strength of the well-known visible FSO3 band system.