A MATRIX PHOTOCHEMISTRY STUDY ON FC(O)SBR - THE PRECURSOR OF SBRF

The compound SBrF was obtained by UV photolysis of FC(O)SBr in a rare ps matrix. The formation of the radicals .FCO and .SBr during that process is proposed. Shorter irradiation times produce a randomization of the conformers of FC(O)SBr in the matrix. Ab initio methods at the Hartree-Fock level of sophistication predict the following geometric parameters for SBrF: S-F = 1.608 angstrom, S-Br = 2.151 angstrom, Br-S-F = 101-degrees (HF/3-21G*); S-F = 1.577 angstrom, S-Br = 2.156 angstrom, Br-S-F = 101.1-degrees (HF/3-21G* + d(F); additional polarization functions on F, alpha(d) = 0.8). The calculated dipole moments are 1.30 and 0.73 D, respectively. For the sake of comparison, ab initio calculations were also performed for the parent molecule SCIF.