The relative importance of H-bonding and p-stacking in isolated cold complexes of 2-pyridone (2PY) with 1,2,4,5-tetrafluorobenzene (4FB), pentafluorobenzene (5FB), and hexafluoro-benzene (6FB) was investigated. Unexpectedly, only 2PY•6FB exhibits p-stacking in the gas phase and a broad UV spectrum. The other 2PY•nFB complexes show narrow absorption spectra characteristic of doubly H-bonded dimers.

This work was carried out in the group of Prof. Samuel Leutwyler.

References:

• R. Leist, J. Frey, P. Ottiger, H. M. Frey, S. Leutwyler, R. A. Bachorz, W. Klopper;
  "Nucleobase–Fluorobenzene Interactions: Hydrogen Bonding Wins over p Stacking"
  Angewandte Chemie Int. Ed., 46, 7449-7452, (2007); doi:10.1002/anie.200701171.