The crystal structure of valganciclovir hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Valganciclovir hydrochloride crystallizes in space group P2 1 2 1 2 1 (#19) with a = 7.07758(23), b = 11.34599(27), c = 49.3041(22) Å, V = 3,959.22(22) Å 3 , and Z = 8. Solution and refinement of the structure were made difficult by the limited data range, the relatively large size of the structure, the broad diffraction peaks, the relatively low crystallinity, and the significant preferred orientation. The two independent cations are protonated at the N atoms of the valine side chains. The crystal structure is dominated by alternating layers of ring systems and protonated side chains/anions along the c -axis. In addition to the ammonium–Cl hydrogen bonds, the ring systems and side chains are linked into a three-dimensional network by hydrogen bonds. The two independent cations have very different conformations. N–H···Cl, N–H···O, O–H···N, O–H···O, and O–H···Cl, as well as C–H···Cl, C–H···N, and C–H···O hydrogen bonds, are prominent in the structure. The powder pattern is included in the Powder Diffraction File ™ (PDF ® ) as entry 00-071-1641.
The crystal structure of trametinib dimethyl sulfoxide has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Trametinib dimethyl sulfoxide crystallizes in space group P-1 (#2) with a = 10.7533(4), b = 12.6056(5), c = 12.8147(6) Å, α = 61.2830(8), β = 69.9023(11), γ = 77.8038(10)°, V = 1,428.40(3) Å 3 , and Z = 2 at 298 K. The crystal structure contains hydrogen-bonded trametinib and dimethyl sulfoxide (DMSO) molecules. These are arranged into layers parallel to the (101) plane. There are two strong classical hydrogen bonds in the structure. One links the trametinib and DMSO molecules. Another is an intramolecular hydrogen bond. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.
The crystal structure of flumethasone has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Flumethasone crystallizes in space group P2 1 (#4) with a = 6.46741(5), b = 24.91607(20), c = 12.23875(11) Å, β = 90.9512(6)°, V = 1971.91(4) Å 3 , and Z = 4 at 298 K. The crystal structure consists of O–H⋯O hydrogen-bonded double layers of flumethasone molecules parallel to the ac -plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).
The crystal structure of delamanid has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Solution and refinement of the structure presented significant difficulties, and the result should be considered proposed or approximate. Delamanid crystallizes in the space group P2 1 2 1 2 1 (#19) with a = 67.3701(18), b = 12.86400(9), c = 5.65187(12) Å, V = 4,898.19(14) Å 3 , and Z = 8 at 295 K. There are two independent delamanid molecules, with different conformations, which are essentially identical in energy. The crystal structure consists of layers of delamanid molecules perpendicular to the a -axis. The imidazooxazole ring systems stack along the b -axis, and the trifluoromethyl groups make up the boundaries of the corrugated layers. There are no classical hydrogen bonds in the crystal structure. Eight C–H···O and one C–H···N hydrogen bonds contribute to the lattice energy. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File ™ (PDF ® ).
