Journal of Chemical Crystallography最新文献

A cocrystal of 2,3,5,6-tetramethylpyrazine and 1,3,4,5-tetrabromo-2,6-difluorobenzene has been prepared and its crystal structure has been determined via single-crystal X-ray diffraction. Infinite chains of roughly coplanar donor and acceptor molecules are held together by two crystallographically distinct and highly linear Br···N halogen bonds. Four further crystallographically distinct Br···Br halogen bonds are also observed. Each of the two Br atoms in the 3 and 5 positions on the benzene ring acts simultaneously as a halogen bond donor and acceptor to two additional bromines on two neighbouring 1,3,4,5-tetrabromo-2,6-difluorobenzene molecules. These halogen bonds are also classified as type II halogen-halogen contacts. As a result of these contacts, a staggered herringbone arrangement of the infinite chains results. These structural features are shown to be consistent with computed molecular electrostatic potential and Hirshfeld surfaces. The insights gained through this analysis imply that additional systematic variations in the substitution motifs of aromatic halogen bond donors may lead to new structures and properties. As part of this work, a single-crystal X-ray structure of 1,3,4,5-tetrabromo-2,6-difluorobenzene of moderate quality is also reported.

Graphical Abstract

The single-crystal X-ray diffraction structure of a 1:1 cocrystal of 2,3,5,6-tetramethylpyrazine and 1,3,4,5-tetrabromo-2,6-difluorobenzene is reported. Bromine-nitrogen halogen bonds link the two types of molecules together, forming infinite chains. Bromine-bromine halogen bonds (type II contacts) between aromatic molecules stabilize a herringbone-like packing arrangement.

A vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand viz. [V^IVO(salala)(phen)]1.66H₂O (where salala = Schiff base derived from salicylaldehyde and L-alanine, phen = 1,10-phenanthroline) have been synthesized and its structure determined by single crystal X-ray diffraction. The crystal lattice parameters of the complex was determined by single crystal X-ray diffraction with lattice parameters, a = 18.4361 [5] Å, b = 22.4926 [6] Å, c = 12.4035 [6] Å, β = 126.904 [1]°, C2 space group, Z = 2. In the crystal, the V(IV) ions are in distorted octahedral geometry, coordinated to two oxygen atoms and one nitrogen atom of Schiff base ligand and two phenanthroline nitrogen atoms. The π···π stacking interactions as well as C–H···O hydrogen bonds were found to play an important role in the self-assembly of the complex molecules. The non-covalent interactions of the complex were further evaluated by Hirshfeld Surface Analysis. Spectroscopic characterization of the complex by Infrared and UV–visible spectroscopic techniques is also reported.

Graphical Abstract

Crystal structure of a vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand have been determined by single crystal X-ray diffraction and non-covalent interactions between the complex molecules studied by Hirshfeld surface analysis.

A new aqua-tricaesium-sodium polymetavanadate compound, [Cs₃Na(VO₃)₄(H₂O)] (1), was synthesized by reacting caesium chloride and sodium metavanadate at ambient pH. The structure was characterized and identified using single-crystal X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, and energy dispersive X-ray analysis (EDS). Compound (1) crystallizes in an orthorhombic system with a Pnma space group, and cell parameters a = 11.6554(4), b = 8.3408(2), c = 16.1121(5). Vanadium has tetrahedral coordination connected to the next vanadium atom through an oxygen bridge. The infinite zigzag metavanadate chains formed by corner-sharing VO₄ tetrahedral constitute a1D building block. The chains were laterally connected through Cs, Na, and H₂O. This connectivity generates continuous 2D layers within the ab plane. The photocatalytic performance of (1) was evaluated by measuring the degradation of methylene blue under visible light. The results confirmed the efficiency of the photocatalytic activity because of the narrowed bandgap energy of 2.18 eV, and 85% degradation rate, making it suitable for absorbing visible light.

Graphical Abstract

The paper reports the synthesise and characterization of a new isopolyvanadate compound, [Cs₃Na(VO₃)₄H₂O], which contains vanadim in the five oxidation state with tetrahedral coordination.  It forms metavanadate chains interconnected by caesium and sodium cations. The photocatalytic activity was tested by degrading methylen blue under visible light irradiation. The results showed decent activity attributed to the narrowed bandgap energy of 2.18 eV.

Reaction of 4,6-dinitroresorcinol (1) and the nitrogen base 1,4-diazabicyclo[2·2·2]octane (2) affords the 1:2 salt and proton-transfer compound 1,4-diazabicyclo[2·2·2]octane-1,4-diium bis(5-hydroxy-2,4-dinitrophenolate) (3). Compound 3 crystallizes in the triclinic crystal system (space group P-1) with a = 8.3242(5) Å, b = 11.9915(7) Å, c = 12.4595(7) Å, α = 116.282(2)°, β = 100.576(3)°, γ = 101.051(2)°, 1042.30(11) ų and Z = 2. The dication 2-({text{H}}_{2}^{2+}) forms charge assisted donating bifurcated N⁺−H⋅⋅⋅O⁻ hydrogen bonds to the phenolate moieties of two monoanions of 1. The latter exhibit an intramolecular O−H⋅⋅⋅O hydrogen bond between the hydroxy group and the nitro group in ortho position. The crystal structure of 3 features pseudo B-centering of the lattice, which relates the two crystallographically distinct monoanions of 1 by a pseudo translation. The possible B-centring is broken by the ethylene groups of 2-H₂²⁺, which are related in neighbouring molecules by centres of symmetry.

Graphical Abstract

The 1:2 proton-transfer compound 1,4-diazabicyclo[2.2.2]octane-1,4-diium bis(5-hydroxy-2,4-dinitrophenolate) features pseudo B-centering of the lattice.

The crystal structure of tetrachloroferrate(III) complex with methylene blue, [Mb]⁺[FeCl₄]⁻ (where [Mb]⁺ methylthioninium or 3,7-bis(dimethylamino)-phenothiazine-5-ium cation), has been prepared by mechanochemical way and studied by the single crystal X-ray crystallography. The crystal structure of title compound is built from by [FeCl₄]⁻ tetrahedral ion and planar [Mb]⁺ counter ions. The [Mb]⁺ cation is linked in the 3D network by the C–H···Cl hydrogen bonds and is stacked in an antiparallel fashion with the sulfur atom disposed alternatively on an opposite sides of the stacking. The interplanar distance between two neighboring aromatic cycles is 3.431 Å, and a centroids–centroids distance between thiazine rings is 3.975 Å. Dihedral angle between aromatic rings is 1.6°. Intermolecular short contacts were analyzed by 3D Hirshfeld surfaces method and 2D fingerprint plots. Intermolecular interaction energy between two neighboring Mb⁺ cation pair was calculated by using of CE-B3LYP/6-31G(d,p) theoretical level.

Graphical Abstract

The π···π stacking interactions were found plays an important role in the crystal structure formation of the FeCl₃ complex with methylene blue, and calculation by the CrystalExlorer17.5 program indicates that π···π interaction energy between two neighboring methylene blue cations is −33.5 kJ/mol.

Copper(II) and zinc(II) complexes, [Cu(esct)(4-pico)] (1), [Zn(esct)(5,5′-dmbipy)]·H₂O (2), [Cu(esct)(5,5′-dmbipy)] (3), (where H₂esct = 3-ethoxysalicylaldehye-N⁴-cyclohexylthiosemicarbazone) were synthesized by reacting copper acetate/zinc acetate with the thiosemicarbazone derivative (H₂esct) along with heterocyclic bases. The thiosemicarbazone forms doubly deprotonated anions in all the complexes to coordinate via thiolate S, azomethine N and phenolate O atoms. The complexes were characterized by various spectroscopic techniques like infrared, UV–vis, ¹H NMR and EPR spectra. The single crystal XRD studies confirmed the structures. All the three complexes got crystallized in triclinic space group P (overline{1 }.) Complexes are found to have four, five and six coordination around the metal center. The importance of van der Waals interactions in them is explained by Hirshfeld surface analysis. We have used Density Functional Theory (DFT) methods and optimized ground states of the studied complexes using the Gaussian 09 package. Electrostatic potential plots of complexes were investigated. Further, docking studies were carried out with various Epidermal Growth Factor Receptor (EGFR) enzymes.

Graphical Abstract

Three mixed ligand Cu(II) and Zn(II) complexes prepared from a thiosemicarbazone showed interesting geometries and structures

A new complex compound, catena-triglycinium-µ-chlorido-tetrachloridocuprate(II) glycine co-crystal (or glycine-triglycinium pentachlorocuprate), {(C₂H₆NO₂)₃CuCl₅·(C₂H₅NO₂)}_n, was synthesized and studied by single crystal X-ray diffraction (SC XRD) and mid-range infrared spectroscopy. The compound crystallizes in a non-centrosymmetric triclinic P1 space group with lattice parameters a = 5.1277(2) Å, b = 9.1412(6) Å, c = 12.2023(5) Å, α = 101.407(4)°, β = 97.460(3)°, γ = 105.832(4)°, Z = 1. The unit cell contains four glycine ions—three glycinium cations and single zwitter-ion—linked through hydrogen bonds network. The anionic part of the compound is presented by infinite chains [CuCl₆]_n of distorted (elongated) octahedra, connected by vertices and alternating direction of elongated axis. Positions of hydrogen atoms were refined using geometry optimization via density functional theory (DFT) approach. Thermogravimetric analysis (TGA) showed the title compound to be stable in air atmosphere up to ∼ 388‒393 K and decomposes upon further heating.

Graphical Abstract

Unit cell content of the glycine-triglycinium pentachlorocuprate, determined by the SC XRD analysis

Thermolysis of [Ru₃(CO)₁₀(μ-dppm)] (1) in refluxing benzene, followed by chromatographic separation by TLC, afforded the new cluster [HRu₄(CO)₉(μ₃-PhPCH₂PPh₂)(μ₃,η²:η¹:η¹-C₆H₄)] (10) in 7% yield in addition to the previously reported clusters [Ru₃(CO)₉{µ₃-PhPCH₂PPh(C₆H₄)}] (2) and [HRu₄(CO)₉(μ₄-PhPCH₂PPh₂)(μ₄,η⁶:η¹:η¹-C₆H₄)] (8) in 70% and 4% yields, respectively. The molecular structure of 10 has been determined by single-crystal X-ray diffraction analysis. Compound 10 possesses a Ru₄ metal core where two of the six triangular faces are capped by μ₃,η²:η¹:η¹-C₆H₄ (benzyne) and µ₃-PhPCH₂PPh₂ ligands. Compound 10 transforms to the known cluster [HRu₄(CO)₉(μ₃-PhPCH₂PPh₂)(μ₄,η⁶:η¹:η¹-C₆H₄)] (8) slowly at 80 °C. The bonding in the new cluster 10 has been investigated by electronic structure calculations.

Graphical Abstract

A new tetraruthenium cluster has been isolated and structurally characterized from the thermolysis of [Ru₃(CO)₁₀(μ-dppm)] at 80 °C.

The preparation, X-ray crystal structure, Fourier Transform infrared (FTIR) spectroscopy, and elemental analysis of the three complexes (1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione): (2,6-dichlorobenzoic acid)₂: H₂O [(tp)· (Hbza)₂ · H₂O, Hdcba = 2,6-dichlorobenzoic acid] (1) (1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione): (2-pyrazinecarboxylic acid) [(tp) · (Hpyca), Hpyca = 2-pyrazinecarboxylic acid] (2) and (1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione): (3-nitrophthalic acid) [(tp) · (Hntpa)] (3) based on 1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione, 2,6-dichlorobenzoic acid 2-pyrazinecarboxylic acid, and 3-nitrophthalic acid are reported. XRD and FTIR analysis indicated that they are all co-crystal. 1 crystallizes in the monoclinic, space group P2₁/n, with a = 7.1019(7) Å, b = 12.9494(12) Å, c = 26.253(3) Å, β = 93.536(3)°, V = 2409.8(4) ų, Z = 4. 2 crystallizes in the monoclinic, space group P2₁/c, with a = 6.9863(7) Å, b = 25.437(3) Å, c = 7.3987(7) Å, β = 95.152(2)°, V = 1309.5(2) ų, Z = 4. 3 crystallizes in the monoclinic, space group P2₁/n, with a = 14.2133(15) Å, b = 8.2333(9) Å, c = 15.3860(17) Å, β = 117.236(5)º, V = 1600.9(3) ų, Z = 4. The imidazole-carboxylic acid synthon of the CO₂H···N type is observed in all the co-crystal. The imidazole H–N also donated the N–H···O hydrogen bonds in all cases. Apart from the classical hydrogen bonds, the auxiliary expanding interactions as CH···O, CH₃···O, CH···Cl, O···O, Cl···O, Cl···Cl, Cl···π, O···π, and π···π also play important roles in the structure extension. For the coexistence of the various weak interactions these structures adopted the most common R₂²(7) supramolecular synthon. In conclusion, we have shown that 2D–3D connections can be constructed by the collective non-covalent interactions.

Graphical Abstract

In the three prepared supramolecular assemblies there are plenty of weak nonbonding interactions such as directional hydrogen bonds of O–H···N, N-H···O, O–H···O, intra- and interchain CH···O, CH₃···O, CH···Cl, O···O, Cl···O, Cl···Cl, Cl···π, O···π, and π···π interactions, on account of these collective weak interactions, these compounds displayed the 2D–3D framework structures.