Acta Crystallographica Section C Structural Chemistry最新文献

Two 1:1 cocrystals of imidazo[1,2-a]pyridine-3-carbonitrile (IPC) with 4-nitrobenzoic acid (4-NBA) and 4-nitrophenol (4-NP), namely, imidazo[1,2-a]pyridine-3-carbonitrile-4-nitrobenzoic acid (1/1), C₈H₅N₃·C₇H₅NO₄ or (IPC)·(4-NBA) (I), and imidazo[1,2-a]pyridine-3-carbonitrile-4-nitrophenol (1/1), C₈H₅N₃·C₆H₅NO₃ or (IPC)·(4-NP) (II), were obtained and their crystal structures determined by single-crystal X-ray diffraction. Molecules of I and II are both linked by O-H...N, C-H...O and C-H...N hydrogen bonds to form two-dimensional planes, which are further connected into three-dimensional frameworks by C-H...π interactions (in I) and π-π interactions (in II).

The extraction and separation of rare earth elements (lanthanides) can be difficult due to their chemical similarities. Biological processes can have very selective activity towards different elements. We investigated the use of microalgae for this purpose by looking at the interaction of Ce, Gd and Yb with the microalga Chlamydomonas reinhardtii, which has been induced to form polyphosphate granules. X-ray absorption spectroscopy with XANES and EXAFS at the Ce L₃-edge, Gd L₃-edge and Yb L₃-edge was used to characterize the interaction between the lanthanides and the phosphate-containing algae. All three of the lanthanides, added as the chloride salt to the algae, appeared to react to form phosphate compounds. These form both in the presence of phosphate granules or when there is only a low level of P present. CePO₄ could be determined by XANES, but the structures of GdPO₄ and YbPO₄ were determined by EXAFS analysis without reference to the XAS spectra of the standard compounds. It is proposed that C. reinhardtii or other similar microalgae may be useful in the selective removal of rare earths from solution.

The HIV-1 protease inhibitor indinavir sulfate was cleaved via a one-pot reflux synthesis using 1-propanol, yielding the salt bis(2-hydroxy-2,3-dihydro-1H-inden-1-aminium) sulfate, 2C₉H₁₂NO⁺·SO₄^2-. Single-crystal X-ray diffraction (SC-XRD) revealed that the salt crystallizes in the monoclinic space group P2₁. The structure consists of two conformationally distinct cations and one sulfate anion, stabilized through an extensive hydrogen-bonding network. Thermal analysis showed minor solvent loss around 200 °C, followed by a two-step decomposition process commencing at 306.6 °C. Hirshfeld surface analysis revealed dominant O...H/H...O (44.4-41.0%) and H...H (45.2-40.1%) intermolecular contacts, with minor contributions from C...H/H...C and C...O/O...C interactions. These contact percentages were calculated for each of the two independent cations. The van der Waals surface area (687.30 Ų) accounts for 71.43% of the unit cell. These results provide structural and thermal evidence for the transformation of indinavir sulfate under alcoholytic conditions, highlighting the formation and stabilization of the resulting salt.

The crystal structure of the ortho-isomer trans-[N-(2-bromo-3,4,5,6-tetrafluorophenyl)-N',N'-diethylethane-1,2-diaminato(1-)]chloridopyridineplatinum(II), [PtBr_0.1(C₁₂H₁₄BrF₄N₂)Cl_0.9(C₅H₅N)][PtBr_0.4(C₁₂H₁₄BrF₄N₂)Cl_0.6(C₅H₅N)] or [Pt{(o-BrC₆F₄)N(CH₂)₂NEt₂}Cl(py)], 1o, revealed syn and anti rotamers in a 1:1 ratio in the solid state. 1o crystallizes in the centrosymmetric space group P1. The Pt-coordinated Cl ligand exhibits partial occupancy with Br, predominantly in the syn-rotamer. Notably, agostic interactions are observed between the Pt centre and a H atom of one of the ethyl groups. The ortho-isomer 1o was successfully isolated as a side product from the reaction of [Pt{H₂N(CH₂)₂NEt₂}Cl₂], Tl₂CO₃ and C₆F₅Br. While the para-isomer [Pt{(p-BrC₆F₄)N(CH₂)₂NEt₂}Cl(py)], 1p, is the main product, the higher solubility of 1o facilitates its isolation.

The crystalline form of sparsentan (SST) (systematic name: 2-{4-[(2-butyl-4-oxo-1,3-diazaspiro[4.4]non-1-en-3-yl)methyl]-2-(ethoxymethyl)phenyl}-N-(4,5-dimethyl-1,2-oxazol-3-yl)benzenesulfonamide), C₃₂H₄₀N₄O₅S, was produced and characterized using single-crystal and powder X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and IR spectroscopy. The SST molecule displays positional disorder in three different sections. Viability tests of alternative disorder models involved the calculation of energetic contributions to analyse each possible molecular conformation within its crystal environment and identify the energetically most favourable conformations in the lattice.

The crystal structures of N-(furan-3-yl)benzamide, C₁₁H₉NOS, FAP, and N-(thiophen-3-yl)benzamide, C₁₁H₉NO₂, TAP, were determined by single-crystal X-ray diffraction at 173 K. The molecular units in both structures consist of three planar regions: a five-membered aryl ring, an amide linkage, and a phenyl ring. Both compounds crystallize in the space group P1 with no solvent in the unit cell. There are two crystallographically unique, but geometrically similar, molecules in the asymmetric unit of FAP. N-H...O hydrogen bonds in FAP link the molecules into a linear chain lying along the b axis. The asymmetric unit in TAP is a disordered molecule containing contributions from two conformers with different orientations of the thiophenyl ring. N-H...O hydrogen bonds in TAP link the molecules into a linear chain lying along the a axis. Conformations of the gas-phase isolated conformers were predicted with density functional theory (DFT) calculations at the M06-2X/6-31+G(d) level. The conformers in FAP possess similar twist angles with respect to their calculated isolated conformers. However, the DFT calculations revealed a significant difference (>20°) in the twist angles of the thiophenyl rings-amide plane in TAP relative to the predicted gas-phase conformations. The π-stacking ring interactions between hydrogen-bonded molecules in the two crystal structures are not the same and are related to the difference in the magnitude of the dispersion and electrostatic interactions in the FAP and TAP environments..

The crystal structures of eight compounds whose common features are an aromatic ring (naphthalene or benzene) and the presence of two hydroxymethyl groups or two sulfanylmethyl groups were examined. These are the isomers 1,2-, 1,3-, 1,5- and 1,7-bis(hydroxymethyl)naphthalene, C₁₂H₁₂O₂; 2,3-bis(hydroxymethyl)naphthalene, C₁₂H₁₂O₂; 2,3-bis(sulfanylmethyl)naphthalene, C₁₂H₁₂S₂; 1,2-bis(hydroxymethyl)benzene, C₈H₁₀O₂; and 1,2-bis(sulfanylmethyl)benzene, C₈H₁₀S₂. Different positions of the functional groups relative to each other are of fundamental importance in the way the molecules of these compounds are packed in the unit cells and have an impact on the interactions of the molecules of the compounds with each other. The changes that occur in the crystal structures when O atoms are replaced with S atoms in the functional groups are compared. A characteristic feature of the compounds studied is the lack of intramolecular hydrogen bonds between adjacent -OH or -SH groups.

The synthesis and structural characterization of two coumarin derivatives, ethyl 7-(methanesulfonyloxy)-2-oxo-2H-chromene-3-carboxylate, C₁₃H₁₂O₇S, Cou01, and ethyl 7-(benzoyloxy)-2-oxo-2H-chromene-3-carboxylate, C₁₉H₁₄O₆, Cou02, are reported. The compounds were characterized by NMR spectroscopy, mass spectrometry and single-crystal X-ray diffraction. The X-ray diffraction analyses showed that Cou01 crystallized in the orthorhombic space group Pna2₁, while Cou02 crystallized in the monoclinic space group P2₁/c. The packing of both derivatives is controlled by C-H...O hydrogen-bond networks between the coumarin nuclei and the substituent groups at the 7-position. In silico evaluation through density functional theory (DFT) calculations afforded an investigation of the electronic properties, showing that the molecular electrostatic potential (MEP) maps correlate with the formation of hydrogen bonds in the derivatives at the highest and lowest electronic density sites (O and H atoms). The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and HOMO-LUMO gap indicate that Cou01 has good reactivity and electron-donating potential. Global reactivity analysis confirms that this derivative is more reactive (nucleophilic) and polarized. Finally, predictions of antioxidant and anti-inflammatory bioactivities reveal that the substituent group in the 7-position has a significant influence on the bioactivity score predictions and the improvement of toxicological and side effects. Results suggest that Cou01 is a novel and promising molecule with good potential as an antioxidant and anti-inflammatory agent.

The structure of O-ethyl N-phenylthiocarbamate, C₉H₁₁NOS (2), has been redetermined, confirming the results obtained in three earlier structure determinations. The higher data quality provided by modern diffractomers has enabled a reliable analysis (absent from the earlier reports) of the hydrogen bonding. However, conventional refinement of the structure of 2 was unsatisfactory because of the large number of extremely badly-fitting reflections, leading to many checkCIF `ALERT A' messages that might be detrimental to ease of publication. A refinement using nonspherical scattering factors effectively eliminated this problem. There are three independent molecules of 2 in the asymmetric unit; two are directly connected by two N-H...S hydrogen bonds, forming a dimer with the well-known R₂²(8) motif. The other molecule forms a topologically identical but inversion-symmetric dimer. Each type of dimer occupies a different region parallel to the ac plane (molecule 1, y ≃ 0; molecules 2 and 3, y ≃ 1/3 and 2/3). All three molecules lie in planes parallel to (031). The title compound is effectively isotypic to 1-ethyl-3-phenylthiourea (another known structure for which the hydrogen bonding was not analysed) because its EtNH group, like the EtO group of 2, is not involved in hydrogen bonding.

The synthesis and characterization of six novel chromone hydrazide derivatives are described, namely, (E)-2,4-dichloro-N'-[(4-oxo-4H-chromen-3-yl)methylidene]benzohydrazide monohydrate, C₁₇H₁₀Cl₂N₂O₃·H₂O, (I), (E)-4-chloro-N'-[(4-oxo-4H-chromen-3-yl)methylidene]benzohydrazide hemihydrate, C₁₇H₁₁ClN₂O₃·0.5H₂O, (II), (E)-2-methoxy-N'-[(4-oxo-4H-chromen-3-yl)methylidene]benzohydrazide monohydrate, C₁₈H₁₄N₂O₄·H₂O, (III), tert-butyl (E)-2-[(4-oxo-4H-chromen-3-yl)methylidene]hydrazine-1-carboxylate, C₁₅H₁₆N₂O₄, (IV), tert-butyl (E)-2-[(2-amino-4-oxo-4H-chromen-3-yl)methylidene]hydrazine-1-carboxylate, C₁₅H₁₇N₃O₄, (V), and (E)-N'-[(4-oxo-4H-chromen-3-yl)methylidene]acetohydrazide, C₁₂H₁₀N₂O₃, (VI). Compounds (I)-(III) crystallize as hydrates, with water molecules playing a significant role in the hydrogen-bonding networks. The studied compounds exhibit diverse supramolecular architectures driven by various types of hydrogen bonds (N-H...O, O-H...O and O-H...N), weak C-H...O contacts and aromatic π-π stacking interactions. Energy frameworks, illustrating the distribution of the total energy and dispersive energy contributions, predominantly reveal di-periodic patterns that reflect the layered crystal structures. However, in compounds (I) and (III), tri-periodic motifs appear, primarily influenced by dispersive interactions.