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Updated: Apr 22, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Two tautomers in the same crystal: 3-(4-fluoro-phen-yl)-1H-pyrazole and 5-(4-fluoro-phen-yl)-1H-pyrazole
Thammarse S Yamuna1, Manpreet Kaur1, Jerry P Jasinski2
1Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India.
Abstract:
The title co-crystal, 3-(4-fluoro-phen-yl)-1H-pyrazole-5-(4-fluoro-phen-yl)-1H-pyrazole (1/1), C9H7FN2, crystallizes with four independent mol-ecules (A, B, C and D) in the asymmetric unit exhibiting two tautomeric forms (A and D; B and C) due to N-H proton exchange between the two N atoms of the pyrazole ring. The dihedral angles between the mean planes of the pyrazole and benzene rings are 15.6 (1), 19.8 (9), 14.0 (1) and 10.7 (7)° in mol-ecules A, B, C and D, respectively. In the crystal, N-H⋯N hydrogen bonds link the four mol-ecules in the asymmetric unit into a ring with an R 4 (4)(12) motif. Furthermore, weak C-H⋯F inter-actions link the mol-ecules into a three-dimensional network.
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