Information card for entry 1566972

Structure parameters

• Common name: 4,11-Difluoro-quinacridone from Rietveld refinement Remark: This is the correct structural model. The model which fits well to the powder data, fits well to the pair-distribution function, has the lowest energy in lattice-energy minimisations, and agrees with solid-state NMR data. Three wrong structural models are deposited in the CSD as well. Further discussion see publication.
• Chemical name: 4,11-Difluoroquino[2,3-b]acridine-7,14(5H,12H)-dione, wrong structural model A
• Formula: C20 H10 F2 N2 O2
• Calculated formula: C20 H10 F2 N2 O2
• Title of publication: Ambiguous structure determination from powder data: four different structural models of 4,11-difluoroquinacridone with similar X-ray powder patterns, fit to the PDF, SSNMR and DFT-D
• Authors of publication: Schlesinger, Carina; Fitterer, Arnd; Buchsbaum, Christian; Habermehl, Stefan; Chierotti, Michele R.; Nervi, Carlo; Schmidt, Martin U.
• Journal of publication: IUCrJ
• Year of publication: 2022
• Journal volume: 9
• Journal issue: 4
• a: 14.2172 ± 0.0015 Å
• b: 3.76778 ± 0.00016 Å
• c: 13.7038 ± 0.0013 Å
• α: 90°
• β: 102.504 ± 0.012°
• γ: 90°
• Cell volume: 716.66 ± 0.11 ų
• Cell temperature: 300 K
• Ambient diffraction temperature: 300 K
• Number of distinct elements: 5
• Space group number: 14
• Hermann-Mauguin space group symbol: P 1 21/c 1
• Hall space group symbol: -P 2ybc
• Residual factor for all reflections: 0.01504
• Goodness-of-fit parameter for all reflections: 5.275
• Method of determination: powder diffraction
• Diffraction radiation wavelength: 1.54056 Å
• Diffraction radiation type: CuKα~1~
• Has coordinates: Yes
• Has disorder: No
• Has Fobs: No