Preparation and Spectroscopical Studies of FC(O)SSCl

Abstract

The hitherto unknown FC(O)SSCl molecule was prepared by the reaction of ClC(O)SSCl with TlF in vacuum conditions. The molecule was characterized by its electron-impact mass spectrum, the IR spectrum in vapour phase, the Raman spectrum of the liquid, and also the matrix isolated FTIR spectra. FC(O)SSCl is composed by an equilibrium mixture of two conformers, syn-gauche and anti-gauche, both in vapour and liquid phases, with an approximately ratio of 80:20 %. The valence electronic properties were studied by means of photoelectron spectroscopy. The first ionization potential was observed at 10.14 eV, and the HOMO was assigned to the non-bonding electron lone pair located at the S atom bonded to the carbonyl group. A decrease in the dihedral angle of the S-S bond after ionization was predicted by quantum chemical calculations.