Acta Crystallographica Section C

Crystal Structure Communications

Volume 64, Part 6 (June 2008)

organic compounds

gg3148 scheme

Acta Cryst. (2008). C64, o326-o329 [ doi:10.1107/S0108270108013632 ]

3,3',5,5'-Tetramethyl-4,4'-bipyrazole-pentafluorophenol (2/3)

K. V. Domasevitch

Abstract: In the title compound, 2C₁₀H₁₄N₄·3C₆HF₅O, one of the pentafluorophenol molecules resides on a mirror plane bisecting the OF axis. The components aggregate by N-HN, N-HO and O-HN hydrogen bonds involving equal disordering of the H atoms into molecular ensembles based on a 2:1 pyrazole-phenol cyclic pattern [ON = 2.7768 (16) Å and NN = 2.859 (2) Å], crosslinked into one-dimensional columns via hydrogen bonding between the outer pyrazole groups and additional pentafluorophenol molecules. The latter yields a 1:1 pyrazole-phenol catemer with alternating strong O-HN [2.5975 (16) Å] and weaker N-HO [2.8719 (17) Å] hydrogen bonds. This is the first reported molecular adduct of a pentafluorinated phenol and a nitrogen base, and suggests the utility of highly acidic phenols and pyrazoles for developing hydrogen-bonded cocrystals.

Formula: 2C₁₀H₁₄N₄·3C₆HF₅O