Information card for entry 1569411

Structure parameters

• Common name: Leucopterin (variable hydrate) Remark: According to Rietveld refinement, the structure contains a partially occupied H2O molecule, which is represented by a single oxygen atom O1W. Its occupancy value Occ(O1W) = 0.421(8) corresponds to 0.17 H2O per leucopterin molecule. But this value is very uncertain (Powder data of limited quality). Hence, the water content of this structure should be regarded as being between 0 and 0.2 molecules of water per leucopterin molecule. The crystal structure and the tautomeric state were confirmed by DFT-D and SSNMR.
• Formula: C6 H5.34 N5 O3.17
• Calculated formula: C6 H5 N5 O3.2106
• Title of publication: Leucopterin, the white pigment in butterfly wings: structural analysis by PDF fit, FIDEL fit, Rietveld refinement, solid-state NMR and DFT-D.
• Authors of publication: Bravetti, Federica; Tapmeyer, Lukas; Skorodumov, Kathrin; Alig, Edith; Habermehl, Stefan; Hühn, Robert; Bordignon, Simone; Gallo, Angelo; Nervi, Carlo; Chierotti, Michele R.; Schmidt, Martin U.
• Journal of publication: IUCrJ
• Year of publication: 2023
• Journal volume: 10
• Journal issue: 4
• Pages of publication: 448 - 463
• a: 8.10257 ± 0.0004 Å
• b: 4.83656 ± 0.00029 Å
• c: 17.8289 ± 0.0014 Å
• α: 90°
• β: 88.531 ± 0.0042°
• γ: 90°
• Cell volume: 698.46 ± 0.08 ų
• Cell temperature: 296 ± 2 K
• Ambient diffraction temperature: 296 ± 2 K
• Number of distinct elements: 4
• Space group number: 13
• Hermann-Mauguin space group symbol: P 1 2/c 1
• Hall space group symbol: -P 2yc
• Residual factor for all reflections: 0.01192
• Goodness-of-fit parameter for all reflections: 1.591
• 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