S. Chaplot, G. McIntyre, A. Mierzejewski
Oct 15, 1981
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Influential Citations
13
Citations
Journal
Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry
Abstract
The crystal structure of the symmetric 1,3,5-trichloro2,4,6-trifluorobenzene, C6CIaF a, was determined at room temperature by single-crystal X-ray diffraction and at 4.2 K by neutron powder diffraction. The space group is P63/m with a hexagonal primitive cell of dimensions a = b = 8.541 (3) and c = 6.282 (2)/k [which become a = b = 8.441 (2) and c = 6.052 (2)/k at 4.2 K], V = 397/k 3 and Z = 2. The cell contains two planar molecules at 6 (2d) sites. The single-crystal R factor of 3.9% was reached with unconstrained refinement on 401 symmetry-independent Bragg intensities. The structure was solved using constrained refinement on the molecular orientation. Constrained refinement on the thermal parameters has indicated significant internal vibrations in the molecule. The low-temperature study showed there to be no phase transition when the powder is cooled.