Acta Crystallographica Section B

Structural Science

Volume 55, Part 3 (June 1999)

research papers

Acta Cryst. (1999). B55, 375-379 [ doi:10.1107/S0108768198012907 ]

Thermal vibrations in potassium 3-benzoyl-2-thiophenecarboxylate

B. M. Craven and F. L. Ballas

Abstract: The atomic thermal displacement parameters at 293 K for the anion in the title salt have been analyzed in terms of a body having two rigid segments, namely the benzoyl and the 2-thiophenecarboxylate groups. These segments are each nearly planar and have a dihedral angle of 80.1° between them. The internal torsional libration of the anion is physically correlated with its overall external translational and librational motion. Bond distances involving the heavier atoms have an s.u. [sigma] from 0.002 to 0.003 Å while librational corrections in these distances range up to 4 [sigma] . A short nonbonded intersegment CO distance of 2.817 (2) Å becomes 2.831 Å after correction, the correction being 7 [sigma] . An intermolecular SO distance of 3.1891 (14) Å becomes 3.215 Å after correction for independent vibration of the two molecules, the correction being 18 [sigma] .