Crystal and molecular structure of S-methyl(pentafluorosulfanyl)thiocarbamate

The X-ray structure of S-methyl(pentafluorosulfanyl)thiocarbamate, SF₅NHC(O)SCH₃, has been determined from three-dimensional diffractometer data and refined by full-matrix least-squares techniques. The crystals are monoclinic:P2₁/m, a=5.008 (5), b=7.811 (2), c=9.348 (4) Å, β=99.08 (7)°, and Z=2; final R=0.046 for 517 observed reflections. The structure comprises hydrogen-bonded (NH⋯O) chains with the component monomers in the cis, cis-conformation, i.e., the arrangement of the nonhydrogen and nonfluorine atoms is nearly planar, the SF₅ group and the O are in a cis position with respect to the C-NH bond, and the O and the CH₃ group are in a cis position with respect to the C(O)-S bond. Theoretical methods including MNDO and molecular modeling were used to study the relative stabilities of the four possible conformations of SF₅NHC(O)SCH₃.