Journal of Chemical Crystallography最新文献

Treatment of [Re₂(CO)₈(NCMe)₂] with caffeine in boiling toluene produces the dirhenium hydrido-carbonyl complex [Re₂(CO)₈(µ,η¹,κ¹-C₅N₄(CH₃)₃O₂}(µ-H)] (1) in low yield. Complex 1 is formed during this reaction through a C–H bond activation of caffeine at the imidazole ring. Crystal structure of 1, determined by XRD analysis, reveals that both the metalated caffeine and hydride act in bridging capacity by spanning across the rhenium-rhenium vector. The bonding in 1 has been confirmed by DFT calculations.

Graphical abstract

A new dirhenium complex containing a metalated caffeine ligand has been isolated and structurally characterized from the reaction of [Re₂(CO)₈(NCMe)₂] with caffeine.

The synthesis, X-ray crystallographic, and spectroscopic studies of N-(4-chlorophenyl)-6-[(4-chlorophenyl)carbamothioyl]pyridine-2-carboxamide (Cl-pcta) grown from EtOAc/ hexane (1:8) is reported. The compound crystallized in a monoclinic space group P 2₁/c with a = 9.8905(4) Å, b = 21.5491(9) Å, c = 8.9818(4) Å, β = 111.1277(13)° and V = 1785.62(13) ų with Z = 4. The structure of Cl-pcta is pseudo-planar with the Cl-aryl rings twisted in opposite directions out of the plane of the pyridyl ring. The packing of the molecules were stabilized by classical hydrogen bonding between NH and C = O/C = S groups. In the ¹H NMR the NH(C = O) and the NH(C = S) where observed at 9.44 and 11.19 ppm, respectively. In the IR spectrum, the NH(C = O) and the NH(C = S) were also resolved and observed at 3216 and 3302 cm^–1, respectively; coherent with the asymmetrical nature of the molecule.

Graphical abstract

Synthesis, X-ray crystallographic and spectroscopic studies of N-(4-chlorophenyl)-6-[(4-chlorophenyl)carbamothioyl]pyridine-2-carboxamide. The synthesis, X-ray crystallographic, and spectroscopic studies of N-(4-chlorophenyl)-6-[(4-chlorophenyl)carbamothioyl]pyridine-2-carboxamide (Cl-pcta) is reported.

A methanol solvate of the tetranuclear Cu(II) complex with 4-methoxypyridine (4-MOP) as co-ligand have been synthesized, [Cu₄OCl₆.(4-MOP)₄].CH₂OH, (4-MOP = 4-methoxypyridine) and characterized by IR, UV–Vis spectroscopy and single crystal X-ray diffraction. The complex exhibits a tetrahedral {Cu₄O} core, where four Cu(II) ions are bridged by six chloride ligands and further stabilized through coordination with 4-methoxypyridine ligands. Each copper center displays a distorted trigonal bipyramidal geometry. Intermolecular C–H···Cl and C–H···O hydrogen bonds interconnect the molecules, forming a three-dimensional supramolecular framework. Spectroscopic data, including UV-Vis and FT-IR, substantiate the formation of the Cu₄O cluster and align with the structural observations. These findings offer valuable insights into the coordination behavior and supramolecular organization of µ₄-oxo copper complexes, presenting a useful model for biomimetic systems and a potential foundation for applications in catalysis and material science.

Graphical Abstract

A rare example of a µ₄-oxo-bridged tetranuclear Cu(II) complex stabilized by 4-methoxypyridine ligands has been selectively synthesized and structurally characterized. This is among the few known Cu₄OCl₆ type architectures incorporating 4-MOP, revealing a well-defined {Cu₄O} core and a 3D supramolecular network through weak hydrogen bonding.

The title compound (1) was synthesized through reaction between Pd(CH₃CN)₄(BF₄)₂ and m-xylylenebis(pyridyltriazole) (m-xpt) in a mixture of CH₂Cl₂ and CH₃CN. The solid product was crystallized by vapor diffusion of ethyl ether into a DMSO solution. In the crystal structure of 1, square-planar trans-[Pd(pyridyltriazole)₂]²⁺ groups are joined by m-xylylene bridges to make centrosymmetric [Pd₂(m-xpt)₂]⁴⁺ cations with Pd⋯Pd = 5.1337(4) Å. As in previously published structures with the isomeric o-xpt ligand, ([Ag₂(o-xpt)₂]²⁺ and [Pd₂(o-xpt)₂]⁴⁺), the Pd(pyridyltriazole)₂ planes in 1 make close π contact (3.302 Å); this is accomplished by twisting of the m-xpt bridging groups, so that the longer Pd⋯Pd vector makes a 40° angle with the Pd(pyridyltriazole)₂ planes.

Graphical Abstract

The crystal structure of the title compound shows a Pd⋯Pd distance approximately as expected (5.1337(4) Å), but with its m-xylylene groups twisted in order to permit close π–π interactions (3.302 Å) between its Pd(pyridyltriazole)₂ planes.

A new tetrameric complex of Ba(II), [Ba₄(PA)₄(H₂O)₂₀]·4H₂O (PA = pamoate) has been prepared by gel diffusion technique at ambient condition. The grown crystals were characterized by elemental analysis, single crystal X-ray diffraction studies, thermogravimetry, FT-IR and UV–visible spectral studies. The single crystal X-ray diffraction studies show that the crystal structure consists of two different types of nine coordinated Ba centers (Ba1 and Ba2). In addition to the carboxylate groups of pamoate, two coordinated water also interconnect the Ba(II) centers. The carboxylate groups of pamoate exhibit monodentate, bismonodentate and bidentate, coordination modes with Ba(II) ions. Hydrogen bonding further stabilizes the crystal structure. Photoluminescence studies were also carried out.

Graphical Abstract

A new tetrameric complex of Ba(II) with pamoic acid (H₂PA) of formula [Ba₄(PA)₄(H₂O)₂₀]·4H₂O (BaPA) has been prepared by gel diffusion technique at ambient condition and is characterized by various analytical techniques.

A new lead tri-magnesium phosphate PbMg₃(HPO₄)(PO₄)₂ was synthesized by hydrothermal method and characterized by single crystal X-ray diffraction. This phosphate crystallizes in the monoclinic system with space group I2/m and unit cell parameters a = 6.6403(2)Å, b = 13.1169(5) Å, c = 10.7153(4) Å and β = 90.194 (1)°. The structure consists of two edge-sharing [MgO₆] octahedra linked to [PO₄] or [HPO₄] tetrahedra to build [Mg₂P₂O₁₄] and [Mg₂H₂P₂O₁₄] moieties, which are interconnected together through vertices to form a sheet parallel to (1 0 0) plan. In addition, an infinite chain ([MgPO₉]_∞) formed by the sharing of a vertex between the [MgO₆] octahedron and the [PO₄] tetrahedron ensures the connection of the sheets to form a three-dimensional structure containing tunnels parallel to the b and c axes. The Pb²⁺ and H⁺ cations are located in disordered sites in these tunnels. The structure of this phosphate exhibits also a strong hydrogen bond.

Graphical Abstract

(A) and (C) Polyhedral representation of the structure showing the tunnels along the [010] and [001] directions that house Pb and H atoms. The dashed lines in the tunnels of (C) represent the hydrogen bond O1–H1…O1ⁱ. (B) Infinite chain [MgPO₉]_∞ formed by alternating [MgO₆] octahedra and [PO₄] tetrahedra, which connect the layers stacked along the c-axis.

The monomeric magnesium complex, C₄H₈N₅⁺[Mg(C₇H₂N₂O₇)₂(H₂O)₂]·2 H₂O, crystallizes in a triclinic P-1 space group. In this structure, Mg(II) ion adopts an octahedral geometry. The coordination sphere around the metal center is formed by four oxygen atoms from two bidentate 3,5-dinitrosalicylate anions (DNS) in the equatorial plane, while two oxygen atoms from coordinated water molecules occupy the axial positions. Extensive hydrogen bonding stabilizes the crystal structure with the non-coordinated 2,4,6-triaminopyrimidinium cation (TAP) generating primary ring motifs such as R₂²(8) and R₂³(8), which extend into a complex three-dimensional hydrogen-bonded network. Coordinated and non-coordinated water molecules play a crucial role in maintaining the supramolecular framework by engaging in N–H…O, O–H…O and O–H…N hydrogen bonding interactions. Additionally, π–π stacking interactions contribute to the stabilization of the structure. These cooperative non-covalent interactions not only strengthen the crystal packing but also contribute to the overall stability of the supramolecular architecture, making this complex a potential candidate for future studies in crystal engineering and molecular assembly.

A novel transition metal complex was synthesized from the reaction between the copper(II)acetate and the Schiff base ligand (E)-2,4-di-tert-butyl-6-((2-fluorophenylimino)methyl)phenol. The title complex was structurally characterized by single crystal X-ray diffraction technique. Crystallographic analysis revealed that the copper(II) center in the investigated complex is four-coordinate, consisting of two imine nitrogen atoms and two phenolic oxygen atoms from two bidentate Schiff bases. The coordination geometry is a distorted seesaw configuration with a τ4 index of 0.33. Hirshfeld surface analysis was employed to investigate the intermolecular contacts within the crystal structure using 3D d_norm surface and 2D fingerprint histograms. The fingerprint plots indicated that the dominant contacts were Van der Waals interactions (H···H, 74.3%), with C···H and H···F interactions also contributing significantly to the overall packing. Density functional theory calculations with the B3LYP/LanL2DZ level were used to calculate the molecular geometric structure of the Cu(II) complex in the ground state. The calculated values were compared with the crystallographic one. Additionally, Natural Bond Orbital (NBO) analysis was performed using the same basis set. The electronic properties of the atoms within the coordination environment and their hyperconjugative interactions were evaluated using NBO analysis.

Graphical Abstract

In this study, the synthesis of a copper(II) complex compound, some DFT calculations, single-crystal X-ray and Hirshfeld surface analyses were performed and interpreted

The compound 1,4,7-trithia-10,13-diazacyclopentadecane-9,14-dione, 1, crystallizes in the space group P2₁/c with a = 9.3608(3) Å, b = 16.0333(5) Å, c = 9.5608(3) Å, β = 113.3521(14)°, and Z = 4. The title molecule forms chains via face-to-face N–H^…O hydrogen bonds. The structure of 1 is also compared to the previously reported oxygen analog, 1,4,7-trioxa-10,13-diazacyclopentadecane-9,14-dione.

Reaction of even parity primary alkyl amines with propanesultone produces 3-(N-alkylammonium)propanesulfonate inner salts as slightly-soluble solids in polar solvents and in good yields. A short series of amines, n-C_nH_2n+1NH₂ with n = 4, 6, 8, 10, was studied. Crystals of the N-butyl analog from water occurred as a dihydrate, orthorhombic, P nma, with molecules lying on mirror planes and waters in general positions. Secondary ammonium ions are hydrogen-bonded to waters of crystallization, which are hydrogen-bonded to sulfonate oxygens with only two-centered⁺N-H…O_w and O-H…O^- interactions. Beginning with the N-hexyl homolog, crystals are polycrystalline, fibrous and with sufficient alignment coherence to allow determination as though single crystals. The degree of fiber misalignment was 3–5^o, approximately. Crystals from water are triclinic (unsolvated), P -1, with molecules lying between crystal (0 2 2) planes. Molecular packing shows adjacent molecules hydrogen-bonded between secondary ammonium ions and sulfonate ions in which all ⁺N-H…(O, O’)^- interactions are three-centered. Terminal alkyl groups pack in adjacent regions so that both hydrogen-bonding and dispersion attractions contribute to increasing intermolecular attractions and melting temperatures, exceeding 260 ^oC for the N-decyl homolog. The four compounds are further characterized by infrared spectroscopy and proton and carbon magnetic resonance spectroscopy and solubilities in common solvents.

Graphical Abstract

3-(N-Butylammonium)propanesulfonate zwitterions are mirror symmetric in P nma, while hexyl, octyl and decyl homologs are fibrous triclinic (P -1) structures with molecules lying approximately along the (0 1 1) planes