Structural analysis, matrix Raman spectra, syn-anti photoisomerization and pre-resonance Raman effect of fluorocarbonylsulfenyl chloride, FC(O)SCl

The crystal structure of fluorocarbonylsulfenyl chloride, FC(O)SCI, was determined by X-ray diffraction analysis from crystals obtained at low temperature using a miniature zone melting procedure. The molecule exhibits only one form with C-s symmetry: the C=O double bond syn with respect to the S-Cl single bond. The matrix Raman spectrum of FC(O)SCl shows features originated by two conformers, which are in equilibrium in the gas phase. Irradiation of the Ar-matrix with UV light of lambda < 300 nm produces randomization. The pre-resonance Raman effect was also determined for the molecule. Its extension is associated with the planarity of the molecule and it is related to the pi-->pi* transition in the chromophore. Theoretical calculations reproduce both experimental parameters and vibrational data very well. (C) 1999 Elsevier Science B.V. All rights reserved.