The crystal structure of cephalexin monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Cephalexin monohydrate crystallizes in space group C2 (#5) with a = 27.32290(17), b = 11.92850(4), c = 16.75355(8) Å, β = 108.8661(4)°, V = 5166.99(3) Å3, and Z = 12. Although the general arrangement of molecules is similar to that in cephalexin dihydrate, the structural differences result in very different powder patterns. The crystal structure is characterized by alternating layers of hydrogen bonds and van der Waals contacts parallel to the bc-plane. The water molecules occur in clusters. Five of the six protons in the water molecules act as donors in O–H⋯O hydrogen bonds. The sixth hydrogen atom acts as a donor to two different phenyl ring carbon atoms to form bifurcated O–H⋯C hydrogen bonds. Each cephalexin molecule is a zwitterion, containing ammonium and carboxylate groups. The ammonium ions form N–H⋯O hydrogen bonds to carboxylate groups and water molecules, as well as to carbonyl groups. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1417.

The crystal structure of ceftriaxone sodium hemiheptahydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Ceftriaxone sodium hemiheptahydrate crystallizes in the space group C2 (#5) with a = 30.56 492(16), b = 4.75 264(2), c = 18.54 978(16) Å, β = 90.3545(6), V = 2694.562(21) Å3, and Z = 4. Both Na exhibit trigonal bipyramidal coordination. Prominent in the structure are alternating Na/O and organic layers perpendicular to the c-axis. There are many O–H⋯O hydrogen bonds involving the water molecules and the ionized portions of the anion. There are a surprising number of C–H⋯S hydrogen bonds, as well as C–H⋯N and C–H⋯O hydrogen bonds. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

The crystal structure of atazanavir has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Atazanavir crystallizes in space group P21 (#4) with a = 15.33545(7), b = 5.90396(3), c = 21.56949(13) Å, β = 96.2923(4)°, V = 1941.134(11) Å3, and Z = 2. Despite being labeled as “atazanavir sulfate”, the commercial reagent sample consisted of atazanavir free base. The structure consists of an array of extended-conformation molecules parallel to the ac-plane. Although the atazanavir molecule contains only four classical hydrogen bond donors, hydrogen bonding is, surprisingly, important to the crystal energy. Both intra- and intermolecular hydrogen bonds are significant. The hydroxyl group forms bifurcated intramolecular hydrogen bonds to a carbonyl oxygen atom and an amide nitrogen. Several amide nitrogens act as donors to the hydroxyl group and carbonyl oxygen atoms. An amide nitrogen acts as a donor to another amide nitrogen. Several methyl, methylene, methyne, and phenyl hydrogens participate in hydrogen bonds to carbonyl oxygens, an amide nitrogen, and the pyridine nitrogen. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1426.

The new compound (4R)-methyl-3-(1-(4-chlorophenyl)-1H-1,2,3-triazole-4-carbonyl)thiazolidin-4-carboxylate was synthesized by the 1,3-dipolar cycloaddition reaction between (4R)-methyl-3-propionyl-thiazolidin-4-carboxylate (1) and 4-chlorophenylazide using the click chemistry approach. Molecular characterization was carried out by infrared spectroscopy and mass spectrometry. The X-ray powder diffraction study determined that the title compound crystallized in an orthorhombic system with unit-cell parameters a = 20.876 (2) Å, b = 12.111 (1) Å, and c = 6.288 (9) Å. The volume of the unit cell is V = 1589.7 (2) Å3. All measured diffraction maxima were indexed and are consistent with the P2221 space group (No. 17). No detectable impurities were observed.

Single-crystal and powder X-ray diffraction data, collected at room temperature, unit-cell parameters and space group for eluxadoline nitrate monohydrate, C32H35N5O5⋅2HNO3⋅H2O, are reported [a = 11.066(5) Å, b = 13.452(6) Å, c = 24.373(9) Å, unit-cell volume V = 3628.15 Å3, Z = 4, ρcal = 1.344 g⋅cm−3, and space group P212121]. All the diffraction peaks in the experimental pattern have been indexed and are consistent with the P212121 space group.

The crystal structure of atorvastatin calcium trihydrate (ACT) has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. ACT crystallizes in space group P1 (#1) with a = 5.44731(4), b = 9.88858(16), c = 29.5925(10) Å, α = 95.859(3), β = 94.211(1), γ = 105.2790(1)°, V = 1521.277(10) Å3, and Z = 1. The most prominent feature of the crystal structure is a hydrophilic layer parallel to the ab-plane. The atorvastatin anions bond to each side of the hydrophilic layer, forming a triple layer. The calcium coordination is distorted octahedral, with the CaO6 coordination sphere being comprised of four carboxylate oxygens, one coordinated water molecule, and a hydroxyl group from one but not the second atorvastatin anion. Several O–H⋯O hydrogen bonds form a two-dimensional network parallel to the ab-plane. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

The crystal structures of two forms of alclometasone dipropionate have been solved and refined using a single synchrotron X-ray powder diffraction pattern and optimized using density functional techniques. Both forms crystallize in the space group P212121 (#19) with Z = 4. The lattice parameters of Form 1 are a = 10.44805(7), b = 14.68762(8), c = 17.31713(9) Å, and V = 2657.44(2) Å3, and those of Form 2 are a = 10.69019(13), b = 14.66136(23), c = 17.17602(23) Å, and V = 2692.05(5) Å3. Both density functional theory and molecular mechanics optimizations indicate that Form 2 is lower in energy, but the differences are within the expected uncertainties of such calculations. In both forms, the only traditional hydrogen bond is between the hydroxyl group and the ketone in the steroid A ring. The chlorine atom acts as an acceptor in two intramolecular C–H⋯Cl hydrogen bonds involving ring hydrogens, as well as in an intermolecular hydrogen bond involving a methyl group. There are several C–H⋯O hydrogen bonds, mainly to ketone oxygens, but also to the hydroxyl group and an ether oxygen. The powder patterns have been submitted to ICDD for inclusion in the Powder Diffraction File™.

The crystal and molecular structure of fenspiride, a bronchodilator and anti-inflammatory drug, are reported. Fenspiride crystallizes in the monoclinic system, with two crystallographically independent molecules in the general position of the space group P21/n (No. 14) and Z = 8. Rietveld refined unit cell parameters are a = 11.52013(8) Å, b = 5.614091(31) Å, c = 44.1567(4) Å, α = 90°, β = 93.0885(6)°, γ = 90°, and V = 2851.69(4) Å3.

The crystal structure of oseltamivir phosphate has been refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Oseltamivir phosphate crystallizes in space group P21212 (#18) with a = 24.0079(3), b = 24.6716(2), c = 7.45254(5) Å, V = 4414.24(5) Å3 at 295 K, and Z = 8. Prominent in the crystal structure are hydrogen bonds between the phosphate groups and the ammonium groups of the oseltamivir cations. The strong hydrogen bonds link the cations and the anions into columns parallel to the c-axis, with van der Waals interactions between the columns. Thermal expansion between 120 and 295 K is anisotropic. The powder pattern is included in the Powder Diffraction File™ as entry 00-068-1107.

The crystal structure of pantoprazole sodium sesquihydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Pantoprazole sodium sesquihydrate crystallizes in space group Pbca (#61) with a = 33.4862(6), b = 17.29311(10), c = 13.55953(10) Å, V = 7852.06(14) Å3, and Z = 16. The crystal structure is characterized by layers parallel to the bc-plane. One layer contains the Na coordination spheres. The two independent sodium ions are trigonal bipyramidal and octahedral. The NaO3N2 and NaO4N2 coordination spheres share an edge to form pairs. The sodium bond valence sums are 1.17 and 1.15. The difluoromethyl groups are probably disordered. Two water molecules act as hydrogen bond donors to pyridine nitrogen atoms and sulfoxide oxygen atoms. The third water molecule participates in bifurcated hydrogen bonds, but one of its hydrogen atoms does not participate in hydrogen bonds. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1424.

The crystal structure of ipratropium bromide monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Ipratropium bromide monohydrate crystallizes in the space group P21/c (#14) with a = 8.21420(7) Å, b = 10.54617(13) Å, c = 24.0761(39) Å, β = 99.9063(7) °, V = 2054.574(22) Å3, and Z = 4. Both hydrogen atoms of the water molecule act as donors to the bromide cation, forming a ring with the graph set R2,4(8). The hydroxyl group also acts as a donor to Br. Several C–H⋯Br hydrogen bonds are present. The water molecule acts as an acceptor in two C–H⋯O hydrogen bonds from methyl groups. The ketone acts as an acceptor in C–H⋯O hydrogen bonds from methyl groups, a methylene group, and a methyne group. The hydroxyl group acts as an acceptor in a C–H⋯O hydrogen bond from a phenyl carbon atom. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1611.