Weak hydrogen bonds C-H center dot center dot center dot S and C-H center dot center dot center dot F-C in the thiirane-trifluoromethane dimer

摘要

The complex thiirane-trifluoromethane ((C2H4SHCF3)-H-...) has been observed in a supersonic expansion using Fourier-transform microwave spectroscopy. Its structure was derived from the rotational spectra of the parent and three minor S-34 and C-13 isotopomers observed in natural abundance. The thiirane-trifluoromethane dimer exhibits an equilibrium C, symmetry stabilized by one C-(HS)-S-... and two C-(HF)-F-...-C weak hydrogen bonds. The rotational spectrum shows A-E splittings due to the internal rotation of trifluoromethane in the complex around an axis close to its C-H bond, suggesting that the C-(HS)-S-... linkage is the primary hydrogen bond interaction in the dimer. (C) 2004 Elsevier B.V. All rights reserved.