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 P212121 (#19) with a = 7.07758(23), b = 11.34599(27), c = 49.3041(22) Å, V = 3,959.22(22) Å3, 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.

High-energy mixing offers a novel approach to enhancing the efficiency of Portland cements that incorporate supplementary cementitious materials regarding the hydration time and compressive strength formation. This research focused on monitoring the formation and degradation of mineral phases, as well as the compressive strength development and heat flow of mortars, within the first 48 hours, using clinker-efficient Portland composite cements. This study involved mixing Portland cement containing 20 wt% amorphous blast furnace slag and 10 wt% limestone with water using three different high-energy mixing techniques. The results demonstrated that the compressive strength of the Portland composite cements was comparable to that of ordinary Portland cement within a 48-hour period. Rietveld refinement was employed to track the formation of portlandite and the sum of the amorphous phases quartz and tobermorite, as well as the degradation of tricalcium silicate. The decline in tricalcium silicate and the formation of Portlandite showed a significant increase in reaction speed due to high-energy mixing. Additionally, a reduction in calcite content was observed, suggesting that calcium carbonate contributes to the enhanced compressive strength observed within the first 48 hours.

The leucite group structures are tetrahedrally coordinated silicate framework structures with some of the silicate framework cations partially replaced by divalent or trivalent cations. These structures have general formulae A2BSi5O12 and ACSi2O6, where A is a monovalent alkali metal cation, B is a divalent cation, and C is a trivalent cation. These leucites can have crystal structures in several different space groups, dependent on stoichiometry, synthesis conditions, and temperature. Phase transitions are known for temperature changes. This paper reports a high-temperature X-ray powder diffraction study on RbGaSi2O6, which shows a phase transition from I41/a tetragonal to Iad cubic on heating from room temperature to 733 K. On cooling to room temperature, the crystal structure reverts to I41/a tetragonal.

The crystal structures of two arylcyclohexylamine derivatives – methoxmetamine·HCl (2-(3-methoxyphenyl)-2-(methylamino)cyclohexan-1-one hydrochloride, MMXE·HCl) and methoxetamine·HCl (2-(ethylamino)-2-(3-methoxyphenyl)cyclohexan-1-one hydrochloride, MXE·HCl) – have been determined using laboratory X-ray powder diffraction data contained in the Powder Diffraction File™. MMXE·HCl and MXE·HCl exhibit anesthetic and sedative effects and have been illicitly used as recreational drugs due to their dissociative hallucinogenic and euphoriant effects. The structure determination of MMXE·HCl and MXE·HCl was carried out with DASH, and the Rietveld refinements were performed with TOPAS Academic in monoclinic unit cells. The parameters obtained for MMXE·HCl were a = 15.0429(5) Å, b = 14.0721(5) Å, c = 6.5716(2) Å, β = 90.9864(14)°, and V = 1,390.91(8) Å3, with Z = 4 and space group P21/n. The parameters obtained for MXE·HCl were a = 8.7772(5) Å, b = 9.9528(7) Å, c = 8.5841(6) Å, β = 100.276(3)°, and V = 737.86(8) Å3, with Z = 2 and space group P21. The structures were validated by dispersion-corrected DFT calculations. Hirshfeld surface analysis and fingerprint plots calculations are also reported.

CrFeCoNi high-entropy alloy (HEA) powder with an equimolar composition was produced via gas atomization and applied as a coating using the cold-spray technique. X-ray diffraction patterns were analyzed to characterize the microstructure of the raw HEA powder and cold-sprayed coatings using Rietveld refinement methods. The HEA powders exhibited a single-phase face-centered cubic crystal structure with a lattice parameter of 0.357349(1) nm, a low microstrain of 4.3(0.17) × 10−4, and a crystallite size of 225(8) nm, attributed to the rapid cooling during atomization. In contrast, the cold-sprayed coatings exhibited broadened diffraction peaks, with a reduced crystallite size of 67.9(1.2) nm and an increased microstrain of 2.2(0.23) × 10−3, showing crystallite size refinement and an increase in the density of crystalline defects due to severe plastic deformation during deposition. Additional microstructural analysis revealed texture in the {200} plane and intrinsic stacking fault probabilities increasing to 4.4(0.21) × 10−3. These findings highlight microstructural changes produced by the cold-spray process. This study provides valuable insights into optimizing cold-spray parameters and tailoring HEA properties for industrial applications.

The crystal structure of resmetirom heminonahydrate Form CSI has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Form CSI had been described previously as a dihydrate. Resmetirom heminonahydrate Form CSI crystallizes in space group P-1 (#2) with a = 11.3094(23), b = 15.158(6), c = 16.570(7) Å, α = 67.405(13), β = 74.425(7), γ = 69.526(7)°, V = 2,427.2(4) Å3, and Z = 4 at 298 K. The crystal structure consists of layers of resmetirom molecules parallel to the bc-plane. These layers are separated by water-rich layers also parallel to the bc-plane. A strong N–H···O links the two resmetirom molecules. The equivalent amino group in the other molecule acts as a donor to a water molecule. A number of C–H···O and C–H···N hydrogen bonds also contribute to the lattice energy. Water molecules act as donors to both O and N in the resmetirom molecules. The structure is more complicated than a hydrogen-bonded framework of resmetirom molecules with water in the pores. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD) for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of fluvoxamine hydrogen maleate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Fluvoxamine maleate crystallizes in space group P21/c (#14) with a = 21.6310(15), b = 5.3180(4), c = 19.5555(15) Å, β = 99.979(5)°, V = 2,215.48(25) Å3, and Z = 4 at 298 K. The crystal structure consists of alternating double layers of cations and anions parallel to the bc-plane. Hydrogen bonds link the layers of anions and cations parallel to the bc-plane. The powder pattern has been submitted to the International Centre for Diffraction Data for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of Form A of dequalinium chloride has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Dequalinium chloride Form A crystallizes in space group P42212 (#94) with a = 26.2671(8), c = 9.1119(4) Å, V = 6,286.9(4) Å3, and Z = 8 at 298 K. Despite the conventional representation of the cation, the ring N atoms are not positively charged. The positive charges are distributed on the ring carbon atoms ortho and para to these N atoms. The central decyl chain conformation is more kinked than the all-trans that might be expected in the solid state, but contains only one unusual torsion angle. The crystal structure consists of an array of dequalinium cations, with chloride anions located in regions between the cations. There are short stacks of roughly parallel rings in multiple directions. There is only one classical hydrogen bond in the structure, N–H···Cl between one of the amino groups and one of the chloride anions. Several C–H···Cl hydrogen bonds are prominent, involving ring, chain, and methyl hydrogen atoms as donors. Particularly noteworthy are the hydrogen bonds from the first and second C atoms at each end of the decyl chain. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD) for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of protriptyline hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Protriptyline hydrochloride crystallizes in space group P21/n (#14) with a = 10.10772(19), b = 32.0908(6), c = 10.45302(21) Å, β = 92.8748(10)°, V = 3,386.33(15) Å3, and Z = 8 at 298 K. The crystal structure contains the expected N–H···Cl hydrogen bonds, which link the cations and anions into crankshaft-shaped chains along the c-axis. The cations and the anions form layers parallel to the ac-plane, with van der Waals interactions between the layers. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD®) for inclusion in the Powder Diffraction File™ (PDF®).

The crystal structure of racemic afoxolaner has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Afoxolaner crystallizes in space group P21/a (#14) with a = 9.6014(6), b = 14.0100(11), c = 39.477(10) Å, β = 94.389(7)°, V = 5,294.7(17) Å3, and Z = 8 at 298 K. The crystal structure consists of layers of molecules parallel to the ab-plane. The boundaries of the layers are rich in halogens. Within the layers, there is parallel stacking of rings along both the a- and b-axes. Two classical N–H···O hydrogen bonds link the two independent molecules into dimers. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD®) for inclusion in the Powder Diffraction File™ (PDF®).

Isaac Newton spent some four decades researching “chymistry,” the early modern equivalent of our chemistry. Although his laboratory notebooks survive, his experimental goals remain obscure to the present day. Our work reveals that Newton was engaged in fruitful chemical research even by modern standards. Replication of his experiments, involving Newton’s “vitriol” (from his “liquor of antimony,” NH4Cl, HNO3, and Sb2S3) and verdigris (Cu(CH3COO)2), produced a variety of NH4+-, Cl−-, SO4−2-, NO3−-, and Cu-containing crystallization products. We analyzed these products using powder X-ray diffraction (XRD) (Cu Kα radiation) and Rietveld refinement, which revealed a complex mixture of (NH4)2Cu(SO4)2(H2O)6, NH4NO3, NH4Cl, (NH4)2CuCl4(H2O)2, and (NH4)[Cu(NH3)2Cl3]⋅2H2O. The XRD data also consistently showed a suite of peaks unmatched by any phase in the PDF-5 database. A crystal of the unknown product was analyzed using single-crystal X-ray methods (Mo Kα radiation), revealing a previously unknown compound, (NH4)2[Cu2Cl2(C2H3O2)4]·2NH4Cl, with space group Pmna and room-temperature unit-cell parameters of a = 14.550(3) Å, b = 8.850(1) Å, and c = 9.116(2) Å. The inclusion of this phase in the Rietveld refinements yielded a satisfactory fit. Our ongoing replications of Newton’s crystallization experiments reveal that his research produced a complex, unusual suite of phases, including the aforementioned previously unknown compound.