Powder X-ray diffraction of fluorometholone, C₂₂H₂₉FO₄

Journal Article · Sun Mar 01 00:00:00 EST 2020 · Powder Diffraction

DOI:https://doi.org/10.1017/S0885715619000915· OSTI ID:1608058

Gonzalez, Diana; Golab, Joseph T.; Kaduk, James A. ; Gindhart, Amy M.; Blanton, Thomas N.

Commercial fluorometholone, CAS #426-13-1, crystallizes in the monoclinic space group P 2₁(#4) with a = 6.40648(2), b = 13.43260(5), c = 11.00060(8) Å, β = 92.8203(5)°, V = 945.517(5) ų, and Z = 2. A reduced cell search in the Cambridge Structural Database yielded one previous structure determination, using single-crystal data at 292 K. In this work, the sample was ordered from the United States Pharmacopeial Convention (Lot # R032K0) and analyzed as-received. The room temperature (295 K) crystal structure was refined using synchrotron ( λ = 0.412826 Å) powder diffraction data and optimized using density functional theory (DFT) techniques. Hydrogen positions were included as a part of the structure and were re-calculated during the refinement. The diffraction data were collected on beamline 11-BM at the Advanced Photon Source, Argonne National Laboratory, and the powder X-ray diffraction pattern of the compound has been submitted to ICDD® for inclusion in the Powder Diffraction File™. The agreement of the Rietveld-refined and DFT-optimized structures is excellent; the root-mean-square Cartesian displacement is 0.060 Å. In addition to the O–H⋯O hydrogen bonds observed by Park et al. (Park, Y. J., Lee, M. Y., and Cho, S. I. (1992). “Fluorometholone,” J. Korean Chem. Soc.36, 812–817), C–H⋯O hydrogen bonds contribute to the crystal energy.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: DOE - BASIC ENERGY SCIENCES
• OSTI ID: 1608058
• Journal Information: Powder Diffraction, Vol. 35, Issue 1; ISSN 0885-7156
• Publisher: Cambridge University Press
• Country of Publication: United States
• Language: ENGLISH