Although being an old concern, phosphate analysis is still a tremendous challenge. While many different experimental techniques are found in the literature, very few use powder X-ray diffraction (PXRD) patterns for quantitative phase analysis of different phosphate types. Our measurements performed in four commercial samples of diammonium hydrogen phosphate ((NH4)2HPO4) (DAP) show the existence of phosphate contamination mixtures, such as ammonium dihydrogen phosphate (NH4H2PO4) (ADP). The larger the amount of ADP, the larger the microstrain induced in the DAP phase, which impacts both the aggregation of the nanoparticles in solution and the final anticancer activity of the nanostructure. This study shows that PXRD is an excellent technique for quantitative phase analysis to determine the presence and amount of phosphate contamination in diammonium hydrogen phosphate samples.

A new polymorphic form of sodium selenite pentahydrate is reported in this contribution. We determined its crystal structure from laboratory powder diffraction data recorded at room temperature. It crystallizes in the monoclinic system P21/n with Z = 4. The lattice parameters are a = 15.01473(16) Å, b = 7.03125(7) Å, c = 8.13336(10) Å, β = 98.4458(10)°, and V = 849.345(16) Å3. The crystal structure exhibits a layered structure with isolated 1D chains running along the b-axis.

The crystal structure of meglumine diatrizoate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Meglumine diatrizoate crystallizes in space group P21 (#4) with a = 10.74697(4), b = 6.49364(2), c = 18.52774(7) Å, β = 90.2263(3), V = 1292.985(5) Å3, and Z = 2. Two different crystal structures, which yielded essentially identical refinement residuals and positions of the non-H atoms, were obtained. The differences were in the H atom positions and the hydrogen bonding. One structure was 123.0 kJ/mol/cell lower in energy than the other and was adopted for the final description. The crystal structure consists of alternating double layers of cations and anions along the c-axis. The hydrogen bonds link the cations and anions into a three-dimensional framework. Each of the hydrogen atoms on the ammonium nitrogen of the cation acts as a donor in a strong N–H⋯O hydrogen bond. One of these is to a hydroxyl group of another cation, and the other is to the carboxylate group of the anion. Each of the amide nitrogen atoms of the anion forms a strong N–H⋯O intermolecular hydrogen bond, one to a carbonyl and the other to a carboxylate group. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of danofloxacin mesylate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Danofloxacin mesylate crystallizes in space group P1 (#1) with a = 6.77474(8), b = 12.4973(4), c = 12.82826(28) Å, α = 84.8709(29), β = 87.7501(10), γ = 74.9916(4)°, V = 1044.723(11) Å3, and Z = 2. The protonation of the danofloxacin cations was established by the analysis of potential intermolecular interactions and differs from that expected from isolated-cation calculations. The crystal structure consists of alternating layers of cations and anions parallel to the ac-plane. There is parallel stacking of the oxoquinoline rings along the a-axis. The expected N–H⋯O hydrogen bonds between the cations and anions are not present. Each cation makes an N–H⋯O hydrogen bond with the other cation, resulting in zig-zag chains along the a-axis. Both cations have strong intramolecular O–H⋯O hydrogen bonds. There are several C–H⋯O hydrogen bonds between the danofloxacin cations and mesylate anions. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of 5-(3-methoxyphenyl)indoline-2,3-dione (C15H11NO3) was solved and refined using laboratory powder diffraction data and optimized using density functional techniques. The title compound crystallizes in space group Pbca with a = 11.1772(3) Å, b = 7.92536(13) Å, c = 27.0121(7) Å, and V = 2392.82(10) Å3. The asymmetric unit contains one molecule. Isatin molecules are joined into almost flat chains along the a direction by N–H⋯O bonds. The chains are linked into layers by π-stacking interactions. Finally, the third dimension of the crystal is formed by weaker C–H⋯π and C–H⋯O contacts.

The crystal structure of L-5-methyltetrahydrofolate calcium trihydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Calcium levomefolate trihydrate crystallizes in space group P212121 (#19) with a = 7.1706(6), b = 6.5371(5), c = 53.8357(41) Å, V = 2523.58(26) Å3, and Z = 4. The structure is characterized by alternating hydrophobic and hydrophilic layers along the c-axis. The Ca cations are 7-coordinate, and share edges to form chains along the b-axis. Each of the water molecules acts as a donor in two hydrogen bonds. The coordinated water molecule makes two strong intermolecular O–H⋯O hydrogen bonds to carboxyl and carbonyl groups. The two zeolitic water molecules form weaker hydrogen bonds, to carbonyl O atoms, ring N atoms, and aromatic C atoms. Several N–H⋯O/N hydrogen bonds, as well as C–H⋯O hydrogen bonds, also contribute to the lattice energy.

A new ternary intermetallic compound Al3GaCu9 was synthesized experimentally. A high-quality powder diffraction pattern of the compound was collected by an X-ray diffractometer, and its crystal structure was determined using the Rietveld refinement method. Results show that the compound has a cubic cell with the Al4Cu9 structure type (space group $P\bar{4}3m$ and Pearson symbol cP52). The lattice parameter a = 8.7132(3) Å, unit-cell volume V = 661.52 Å3, calculated density Dcalc = 7.26 g/cm3, and Z = 4. The residual factors converge to Rp = 2.96%, Rwp = 4.06%, and Rexp = 2.57%. The experimentally obtained reference intensity ratio value is 7.04.

X-ray powder diffraction data, unit-cell parameters, and space group for the barium copper iodate, Ba2Cu(IO3)6, are reported [a = 7.48540(15) Å, b = 7.51753(19) Å, c = 7.64259(17) Å, α = 98.8823(7)°, β = 95.0749(7)°, γ = 97.6297(7)°, V = 418.528(9) Å3, Z = 1, and space group P$\bar{1}$]. All measured lines are indexed and are consistent with the corresponding space group. The single-crystal diffraction data of Ba2Cu(IO3)6 are also reported [a = 7.493(3) Å, b = 7.521(6) Å, c = 7.644(5) Å, α = 98.855(18)°, β = 95.060(16)°, γ = 97.62(2)°, V = 419.3(5) Å3, Z = 1, and space group P$\bar{1}$]. The crystal structure of Ba2Cu(IO3)6 features isolated [Cu(IO3)6]4− anionic clusters separated by Ba2+ cations. The experimental powder diffraction pattern matches well with the simulated pattern derived from the single crystal data.

Synchrotron powder diffraction data is presented for a series of relatively phase-pure smectite clay mineral standards obtained from the Clay Minerals Society. Rietveld refinement using a model for turbostratic disorder was performed to estimate the lattice parameters and mineral impurities in the smectite standards. Bragg reflection lists and raw data have been provided for inclusion in the Powder Diffraction File.