Decafluoroquarterphenyl - crystal and molecular structure solved from X-ray powder data

The structure of decafluoroquarterphenyl has been solved and refined from l aboratory X-ray powder data. Structure analysis and nb initio Hartree-Fock calculation showed that the molecules are held by electrostatic interaction s and weak hydrogen bends. A Rietveld refine ment supported by slack constr aints gave dihedral angles which agreed with those found in similar compoun ds. In molecules such as these, where the planarity of the rings is known a -priori, and there is little improvement in the fit to the diffraction data at the expense of distorting the structure, conventional slack constrained Rietveld refinement may not bring much additional information and therefor e may not be worth the additional effort at the end of the structure soluti on process.