The molecular structure of tetrafluorohydroquinone has been determined by electron diffraction in the gas phase. The molecular geometry indicates possible formation of a weak intramolecular hydrogen bond between the OH and F substituents in ortho positions. The nearest H⋯F and O⋯F interactions, at 2.02 ± 0.07 and 2.66 ± 0.05 Å, are closer than the sums of van der Waals radii, 2.55 and 2.75 Å, respectively. The C-OH and C-F bonds are somewhat tilted towards each other. The C-O-H angle, 98 ± 2°, is smaller than in hydroquinone. The C-O bond, (rg), 1.353 ± 0.009 Å, is shorter than in phenol and in hydroquinone. The ring parameters are rg(C-C)mean 1.394 ± 0.003 Å, 〈C-C(OH)-C = 117.0 ± 0.5°, (〈C-C(F)-C)mean = 121.5 ± 0.2°. The angular ring deformation corresponds to additivity of the individual substituent effects with no appreciable consequence of substituent interaction within experimental error. The mean C-F bond length (rg) is 1.346 ± 0.005 Å. A mixture of two conformers with C2v and C2h symmetry is likely.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry