Journal of Chemical Crystallography最新文献

Strychnine is well known as a highly toxic alkaloid derived from the plant Strychnos nux-vomica. It has been applied for chiral separations as a resolving agent for co-crystallizations, as a standard for chromatographic separations, as a rodenticide, as a natural therapy and stimulant, and as a poisonous plot device in works of fiction. Dissolving strychnine into the common organic solvent dichloromethane results in the spontaneous crystallization of the title compound N-(chloromethyl)strychninium chloride. Crystals of the compound were isolated in the orthorhombic space group P2₁2₁2₁ with a = 7.6819(2) Å, b = 7.9621(2) Å, c = 30.7170(9) Å, α = 90°, β = 90°, γ = 90°. The crystal structure has bilayers of N-(chloromethyl)strychninium cations with corresponding bilayers of chloride ions interacting to the cations through C–H hydrogen bonds.

Graphical Abstract

The novel third-order nonlinear optical organic material 4-fluoro-N-[4-(diethylamino)benzylidene]aniline (FDEABA) is synthesized and single crystals of FDEABA are grown using the slow evaporation method. The placement of the protons is confirmed by nuclear magnetic resonance spectral analysis. Employing Fourier transform infrared spectral analysis, vibrational frequencies of various functional groups of the FDEABA compound are identified. The three-dimensional crystal structure of the grown crystal is elucidated using single crystal X-ray diffraction studies, which reveal that the compound FDEABA crystallized in the monoclinic non-centrosymmetric space group P2₁. Intermolecular interactions are studied using Hirshfeld surface analysis and compared with similar structures of halogen-substituted benzylideneaniline derivatives. Thermal stability of FDEABA is measured using thermogravimetric and differential thermal analyses and the melting point of the synthesized FDEABA compound is 51 °C. Open aperture Z-scan measurements carried out at 532 nm using 5 ns laser pulses reveal nonlinear optical absorption leading to strong optical limiting behaviour, which can be useful in the protection of eyes and sensitive optical detectors from harmful laser radiation.

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The reaction of the N,N-diethyl-N'-(p-nitrobenzoyl)thiourea with K₂[PtCl₄] results in the complex of configurational cis-[Pt(L-kS,O)₂], and structurally characterized by elemental analyses, FT-IR, ¹H NMR, ¹³H NMR, UV–Vis spectroscopy, and cis-[Pt(L-kS,O)₂] complex have been also characterized by a single-crystal X-ray diffraction study. The cis-[Pt(L-kS,O)₂] crystallizes in the monoclinic crystal system, space group P2₁/c, with Z = 4, and unit cell parameters, a = 15.09299(15) Å, b = 15.26600(14) Å, c = 14.39268(14) Å, α = 90°, β = 107.6347(11)° and γ = 90°. The single-crystal diffraction analysis of the complex shows that the molecular configuration of cis-[Pt(L-kS,O)₂] is a slightly distorted square-planar geometry, and both deprotonated ligands (L) contribute one O atom and one S atom coordinate with a central Pt(II) ion. The intermolecular interactions in the cis-[Pt(L-kS,O)₂] complex were analyzed using the Hirshfeld surface method, including 2D fingerprint plots. In addition, the fluorescence properties of the compounds at room temperature were also studied. The results show that both ligands and complexes have good fluorescence properties, and the fluorescence intensity of the coordination compound enhances.

Graphical Abstract

In this paper, single-crystal X-ray analysis shows cis-[Pt(L-kS,O)₂] belongs to monoclinic crystal system, space group P2₁/c. The connectivity of the ligand to the metal as 2:1 and the platinum atom is coordinated with two N,N-diethyl-N'-(p-nitrobenzoyl)thiourea ligands in a distorted square-planar geometry.

The crystal structures of 8-R¹-7-bromo-3-tert-butyl-1-R²-pyrazolo[5,1-c][1,2,4]triazin-4(1H)-ones 1a–c, 2a,c (R¹ = CN, CO₂Et, NO₂, R² = H, 1:1 and 3:1 solvates with DMSO; R¹ = CN, CO₂Et, R² = CH₂Boc), 8-R¹-7-bromo-3-tert-butyl-1-R²-1,4-dihydropyrazolo[5,1-c][1,2,4]triazin-4-ols 3a,b (R¹ = CN, R² = n-Bu; R¹ = Br, R² = CH₂Boc), 1,4-dihydro- and aromatic 7-R³-3-tert-butyl-4-R⁴-8-methylpyrazolo[5,1-c][1,2,4]triazines 5a,b, 6 (R³ = H, R⁴ = n-Pr; R³ = Br, R⁴ = n-Bu) were investigated by X-ray diffraction analysis. The structural preferences and different packing modes based on the intermolecular interactions were analyzed by the Hirshfeld surface and energy framework analysis.

Graphical Abstract

The crystal structures of ten 3-tert-butyl-4-oxo, 4-hydroxy- and 4-alkyl-7-bromopyrazolo[5,1-c][1,2,4]triazines including non-solvated, 1:1 and 3:1 solvates with DMSO were investigated by single crystal X-ray diffraction, Hirshfeld surface and energy framework analyses.

Two new proton transfer salts (HABT)⁺(SA)⁻ (1) and (HABT)⁺₂(ADSA)²⁻·2H₂O (2) were synthesized from the reaction of benzo[d]thiazol-2-amine (2-aminobenzothiazole) (ABT) with 2-hydroxybenzoic acid (salicylic acid) (HSA) and 2-aminobenzene-1,4-disulfonic acid (H₂ADSA), respectively. The molecular structures of these salts were carried out by elemental analysis, X-ray diffraction crystallography, FTIR and UV–Vis techniques Single-crystal X-ray analysis of the compounds revealed proton transfer from acidic moieties to basic moieties to form salts with intermolecular hydrogen bond motifs R₂²(8) for 1 and R₃³(10) for 2. The intramolecular hydrogen bond creates the cyclic S(6) motif in both structures (1 and 2). For salt 1, crystallization took place in the P2(1)/c space group of the monoclinic system, and for salt 2 in the P-1 space group of the triclinic system. The antibacterial and antifungal properties of the compounds are assayed against various Gram positive bacteria {Bacillus subtilis, Listeria monocytogenes (ATCC 7644), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (NRRL B-767)}, Gram negative bacteria {Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853)} and fungus {Candida albicans (F89)}. Minimum inhibitory concentrations (MIC) of synthesized salts were compared with antibacterial (levofloxacin cefepime, vancomycin) and antifungal (Fluconazole) reference compounds.

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The adjoined 3d–4f metallacrown (MC) molecule Dy^III₂Mn^III₆(H₂shi)(Hshi)(shi)₇(py)₉·2py·0.7H₂O, 1, where H₃shi is salicylhydroxamic acid and py is pyridine, has been synthesized and characterized by FT–IR spectroscopy and single-crystal X-ray diffraction. The core of the molecule consists of two metallacrown (MC) rings, an archetypal 12-MC-4 and a collapsed 11-MC-4, that are linked through a common ring Dy^III center. For the 12-MC-4 portion of 1, the heterobimetallic composition of the MC ring with one Dy^III and three Mn^III ions is uncommon for metallacrowns as most 12-MC-4 rings are homometallic. In addition, the 12-MC-4 binds a Dy^III cation in the central cavity of the MC. The coordination environment about the central Dy^III ion has a triangular dodecahedron shape, which again is atypical. For 12-MC-4 molecules with a central lanthanide ion, the central lanthanide ion typically adopts a square antiprism geometry. The ring Dy^III cation of the 12-MC-4, which has a biaugmented trigonal prism shape, is shared with the collapsed 11-MC-4 and serves to join both metallacrowns. The collapsed 11-MC-4 ring is also composed of three Mn^III and one Dy^III ions. For one of the ring metal–metal linkages, only an oxygen atom is present, and an eleven membered ring is generated. In addition, the Dy^III center and one of the Mn^III centers bind to ring oxygen atoms on the opposite side of the MC ring; thus, the potential cavity of the MC is collapsed, and the MC does not bind a central metal ion as is customary.

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The preparation and characterization of two supramolecular complexes from octahedral [Ta₆Cl₁₂(CN)₆]^4−/3− units and 2, 2′: 6′, 2″-terpyridine (Terpy) metal complexes as building blocks are reported. Single crystal analyses revealed [Mn(Terpy)]₂[Ta₆Cl₁₂(CN)₆]·MeOH (1) features a neutral two-dimensional (2D) framework composed of layers based on [Ta₆Cl₁₂(CN)₆]⁴⁻ and [Mn(Terpy)]²⁺. Each layer is built of 6-connected [Ta₆Cl₁₂]²⁺ and 3-connected Mn(II) nodes bridged by cyanide ligands. The layers are held together by MeOH molecules. The layered structure is maintained after the removal of solvent molecule (MeOH) upon heating, leading to the formation of [Mn(Terpy]₂[Ta₆Cl₁₂(CN)₆] (1′). In the case of using Gd³⁺, the resultant product was revealed by single-crystal analyses to be an ionic compound [Gd(Terpy)(H₂O)₄(DMF)₂][Ta₆Cl₁₂(CN)₆]⋅DMF ⋅3H₂O (2). 2 has a three-dimensional (3D) framework built of [Gd(Terpy)(H₂O)₄(DMF)₂]³⁺ and [Ta₆Cl₁₂(CN)₆]³⁻ ions connected to each other via extensive hydrogen bonds and π-π interactions between the cations, anions, and solvent molecules. Thermal stabilities of 1‒2 are reported.

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The X-ray structures and thermal stabilities of a coordination polymer [Mn(Terpy)]₂[Ta₆Cl₁₂(CN)₆] ⋅MeOH and an ionic compound [Gd(Terpy)(H₂O)₄(DMF)₂][Ta₆Cl₁₂(CN)₆]⋅DMF⋅3H₂O are presented.

The crystal structures of di-μ-chlorobis[2-(5-methyl-pyridin-2-yl-κN)phenyl-κC(1)] diplatinum(II) (1) and chloro(N,N-dimethylformamide-κO)[2-(5-methyl-pyridin-2-yl-κN)phenyl-κC(1)]platinum(II) (2) have been determined by means of the X-ray diffraction. Both complexes cocrystallize in the monoclinic space group C2/c with a = 39.5457(18) Å, b = 7.2482(4) Å, c = 21.2269(10) Å and β = 121.460(2)°. The asymmetric unit consists of half a centrosymmetric compound (complex 1) and one full independent compound (complex 2).

Graphical Abstract

The X-ray structures of co-crystallized di-μ-chlorobis[2-(5-methyl-pyridin-2-yl-κN)phenyl-κC(1)]diplatinum(II) (1) as starting material and of the derivative chloro(N,N-dimethylformamide-κO)[2-(5-methyl-pyridin-2-yl-κN)phenyl-κC(1)]platinum(II) (2) are reported.