Gas phase structure of ((fluoroformyl)imido)sulfuryl difluoride, FC(O)N [dbnd6]S(O)F 2

Abstract

The geometric structure and conformational properties of gaseous ((fluoroformyl)imido) sulfuryl difluoride, FC(O)N S(O)F 2, was investigated by gas electron diffraction (GED) and quantum chemical methods (MP2 and B3LYP with 6-31G(d) and 6-311+G(2df) basis sets). In combination with earlier reported infrared spectra, the GED study results in a mixture of at least three conformers, 71(10)% syn(N S)– syn(N–C), 14(8)% anti(N S)– syn(N–C) and 15(5)% syn(N S)– anti(N–C). Syn(N S) or anti(N S) implies synperiplanar or anticlinal orientation of the FC(O) group with respect to the SF 2 bisector and syn(N–C) or anti(N–C) implies synperiplanar or antiperiplanar orientation of the C O bond with respect to the N S bond. The anti(N S)– anti(N–C) conformer has not been observed, but a small amount (<5%) cannot be excluded. These conformational properties are well reproduced by quantum chemical calculations with small basis sets and the geometric parameters are reproduced satisfactorily with large basis sets.