On the stability of S(OF)2: A coupled-cluster analysis of the structures and thermochemical properties for conformers of sulfur-oxyfluorides

High level ab initio calculations have been performed on the C2, Cs, and C1 conformers of S(OF)2 using the rigorous (CCSD(T)) method for the first time. Although S(OF)2 has not been detected experimentally, we investigate the structure, harmonic vibrational frequencies, enthalpies of reaction ( Δ H rxn o ), and enthalpies of formation ( Δ H f o ) for these highly reactive prototypical sulfur oxyfluorides species. These calculations have been performed with a number of extended basis sets, namely the cc-pV(T+d)Z, aug-cc-pV(T+d)Z, cc-pV(Q+d)Z, and aug-cc-pV(Q+d)Z to provide benchmark accuracy and assist in the interpretation of potential experimental work. In this report, we recommend preferred values of Δ H f o for the C2 and Cs conformers to be −74.4 and −65.6 kJ mol−1, respectively.