((Fluoroformyl)imido)sulfuryl difluoride, FC(O)N=S(O)F2: structural, conformational, and configurational properties in the gaseous and condensed phases

Structural, conformational, and configurational properties of the gaseous molecule ((fluoroformyl)imido)sulfuryl difluoride, FC(O)N=S(O)F(2), have been studied by vibrational spectroscopy (IR (gas) and Raman (liquid)) and quantum chemical calculations (HF, MP2, and B3LYP with 6-31+G* and 6-311+G* basis sets); in addition, the solid-state structure has been determined by X-ray crystallography. FC(O)N=S(O)F(2) exists in the gas phase as a mixture of a favored antiperiplanar-synperiplanar form (the S=O double bond antiperiplanar with respect to the C-N single bond, and the C=O group synperiplanar with respect to the S=N double bond) in equilibrium with less abundant antiperiplanar-antiperiplanar, synclinal-synperiplanar, and synclinal-antiperiplanar structures. The crystalline solid at 163 K (monoclinic, P2(1)/c, a = 5.1323(7) A, b = 15.942(2) A, c = 16.798(2) A, beta = 95.974(3) degrees , Z = 12) consists of three similar antiperiplanar-synperiplanar forms.