PHOTOCHEMISTRY OF HYDROGEN SULFIDE-FLUORINE COMPLEXES IN SOLID ARGON - INFRARED-SPECTRA OF (HSF)(HF) COMPLEXES

Codeposition of H2S and F2 in excess argon on a cold window at 12 +/- 1 K gave sulfur fluorides and evidence for Lewis acid-base precursor complexes. Photolysis of these complexes with 590-1000-nm light formed several new products. Ab initio SCF calculations with the standard double-zeta plus polarization function (DZP) basis set were performed to support the identification of new product species. The HSF--HF and HFS--HF complexes exhibited H-F stretching modes at 3850 and 3724 cm-1 and S-F stretching modes at 759 and 816 cm-1, respectively. The most stable arrangement was a cyclic (HSF)(HF) complex, which exhibited a strongly perturbed H-F stretching mode at 3383 cm-1 and librational mode at 508 cm-1. The remarkable observation of F2 dissociation at 590 nm in the hydrogen sulfide complexes, as opposed to F2 dissociation at 290 nm in the (H2O)(F2) complex, is attributed to sulfur-fluorine interaction which enhances the continuous red absorption of fluorine.