Acta Crystallographica Section C Structural Chemistry最新文献

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.

The hydrated salt 2-aminothiazolium 3,5-dinitrobenzoate monohydrate, C₃H₅N₃S⁺·C₇H₃N₂O₆^-·H₂O, was synthesized and its structure characterized with single-crystal X-ray diffraction and Hirshfeld surface analysis. In the crystal structure, proton transfer from the carboxylic acid group of the 3,5-dinitrobenzoic acid (DNBA) molecule to the thiazole N atom of the 2-aminothiazole (AT) molecule results in salt formation. The protonation is supported by a widened C-N(H)-C ring bond angle. The primary supramolecular synthon is a heterodimeric R₂²(8) ring motif formed via N-H...O hydrogen bonds. The lattice water molecules play a key role in assembling tetrameric [R₄²(9)] and hexameric [R₆⁵(17)] motifs through N-H...O, OW-HW...O, OW-HW...OW and C-H...OW interactions. These units propagate into hydrogen-bonded chains along the b axis via water-water interactions, which are further linked through C-H...O contacts to generate a 3D network incorporating a large R₈⁸(40) ring motif. The crystal structure is further stabilized by carbonyl-π interactions. Hirshfeld surface analysis reveals prominent red spots in the d_norm mapping, indicating strong O-H...O and N-H...O contacts. 2D fingerprint plots confirm the dominance of O...H/H...O interactions, supporting their important role in the cohesion and stability of the crystal structure.

The neodymium complex triaquatris(hexafluoroacetylacetonato-κ²O,O')neodymium(III) pyridazine trisolvate, [Nd(C₅HF₆O₂)₃(H₂O)₃]·3C₄H₄N₂ or [Nd(hfac)₃(H₂O)₃]·3pdz (hfac is hexafluoroacetylacetonate and pdz is pyridazine), (I), was synthesized via the reaction of [Nd(hfac)₃(H₂O)₂] and pdz, and was characterized by IR spectroscopy and single-crystal X-ray diffraction. The crystal structure reveals that complex (I) crystallizes in the trigonal space group R3c, where the Nd^III ion exhibits a nine-coordinated geometry composed of three bidentate hfac^- ligands and three coordinated water molecules. The UV absorption spectrum displays a strong ligand-centred (LC) absorption band at 302 nm attributed to the π→π* or n→π* transition of the hfac^- moiety. The near-IR luminescence spectrum features a dominant emission peak at 1066 nm, which corresponds to the ⁴F_3/2→⁴I_9/2 transition of the Nd^III ion with a lifetime (τ) of 623.97 ns under excitation at 352 nm. Compared to the precursor [Nd(hfac)₃(H₂O)₂] (τ = 49.70 ns), complex (I) shows a significant increase in luminescence lifetime, which can be attributed to the hydrogen-bonding-induced rigidity that suppresses solvent-induced non-radiative relaxation.

The title compound, (Z)-N-(fluorophenyl)-2-oxopropanehydrazonoyl chloride, C₉H₈ClFN₂O, was found to form concomitant colour polymorphs upon recrystallization from acetone. Block-shaped pale-orange crystals of form I (space group P2₁/n, No. 14) and prism-shaped yellow crystals of form II (space group P2₁/c, No. 14) both belong to the monoclinic crystal system. N-H...O hydrogen bonds resulting in zigzag chains [graph-set descriptor C(6)] are the dominating intermolecular interactions in both crystal forms. The hydrogen-bonded zigzag chains so formed extend by 2₁ screw symmetry in form I and by c-glide symmetry in form II, and are arranged in layers, which are more corrugated in form II than in form I. The polymorphs are virtually indistinguishable by their calculated densities, packing indices and melting points. Form I sublimes to yield crystals of form II, whereas form II sublimes to afford crystals of the same polymorph with characteristic crystal morphology.

Exploring blue emission lead-free halides with high photoluminescence quantum yields (PLQYs) is a significant and challenging issue for luminescent materials. Herein, a zero-dimensional (0D) organic-inorganic hybrid halide, namely, bis[4-(4-chlorophenyl)pyridinium] tetrabromidozincate, (C₁₁H₉ClN)₂[ZnBr₄] or [HCPP]₂[ZnBr₄] [CPP is 4-(4-chlorophenyl)pyridine], was synthesized through acid solution evaporation. The compound crystallizes in the monoclinic space group C2/c. The asymmetric unit consists of a [ZnBr₄]^2- dianion cluster and two monoprotonated [HCPP]⁺ cations. The [ZnBr₄]^2- unit presents an almost undistorted tetrahedral geometry. The [HCPP]⁺ cations adopt nearly coplanar conformations with small dihedral angles of 5.05 (3)°; there are relatively strong π-π interactions between adjacent [HCPP]⁺ cations due to slipped parallel packing, with a distance of 3.81 (1) Å. Significantly, this halide exhibits highly efficient blue-light emission (385-500 nm) with a PLQY of 56.35%.

Celecoxib peroxide (systematic name: 4-{5-[4-(hydroperoxymethyl)phenyl]-3-(trifluoromethyl)-1H-pyrazol-1-yl}benzenesulfonamide), C₁₇H₁₄F₃N₃O₄S, a compound identified in destruction experiments and the long-term storage of the active pharmaceutical ingredient (API) celecoxib, was synthesized and characterized using a variety of techniques, including NMR (¹H and ¹³C), UV, IR, MS and single-crystal X-ray diffraction (SC-XRD). Powder XRD and thermal differential scanning calorimetry/thermogravimetry (DSC/TG) techniques were also employed to further elucidate the features of the crystal. The structure analysis revealed that the molecule is disordered, with the peroxide O atoms distributed over two sites with occupancies of 0.598 (6) and 0.402 (6). The crystal structure features three distinct O-H...N and N-H...O hydrogen bonds, with the latter forming a heterosynthon that results in an R₄²(8) ring motif. Hirshfeld surface (HS) analysis revealed that O...H/O...H interactions were dominant, accounting for 25.3% of the total HS. Energy framework studies were conducted to assess the energetic contribution of supramolecular motifs in stabilizing interaction forces, encompassing dispersion energy and Coulombic energy. The molecular electrostatic potential surfaces (MEPS) indicated a maximum energy of 53.1 kcal mol^-1 and a minimum energy of -35.2 kcal mol^-1. Furthermore, the bond dissociation energies (BDEs) of the peroxide bonds were calculated using the B3LYP density functional theory (DFT) functional with the 6-311+G(d,p) basis set. The results of these calculations suggested that the peroxide bonds possess relatively low energies.