The microwave spectra and structure of the complex 7-oxabicyclo[2.2.1]heptane center dot center dot center dot HF

The hydrogen-bonded complex formed between 7-oxabicyclo[2.2.1]heptane and H F (OBH . . . HF) has been generated in a supersonic jet and characterised b y Fourier transform microwave spectroscopy. The rotational transitions of t he parent and C6H10O . . . DF species, together with the spectra correspond ing to C-13 monosubstituted species have been analysed. Spectral analysis y ielded rotational and centrifugal distortion constants and the parameter D- aa accounting for HF subunit spin (H)-spin (F) coupling. These data are con sistent with C-s symmetry and a linear hydrogen bond lying in the symmetry plane bisector to the angle COC. The structure of the OBH subunit in the co mplex has been determined and it can be concluded that no significant struc tural distortion occurs upon complexation. No detectable inversion doubling attributed to the HF inversion has been observed.