Crystal structure, Hirshfeld surface analysis and DFT studies of tetrakis(μ-3-nitrobenzoato-κ2 O 1:O 1′)bis[(N,N-dimethylformamide-κO)copper(II)] dimethylformamide disolvate

The title compound, [Cu2(C7H4NO4)4(C3H7NO)2]·(C3H7NO)2, is a binuclear copper(II) complex located on an inversion center midway between the two copper(II) cations. The asymmetric unit consists of one CuII cation, two 3-nitrobenzoato ligands, and two dimethylformamide (DMF) molecules, one of which coordinates to the CuII cation and one is a solvate molecule. The carboxylate groups of the ligands bridge two CuII cations with a Cu—Cu distance of 2.6554 (6) Å, completing a distorted octahedral O5Cu coordination environment. The dihedral angles between the carboxylate and the aromatic ring planes of the two independent ligands are different from one another, viz. 5.2 (3) and 23.9 (3)°. The three-dimensional structure is consolidated by weak C—H...O interactions and stabilized by π–π stacking interactions between the aromatic rings. The complex and the free ligand were further characterized by Fourier-transform infrared spectroscopy (FT–IR), and the energies of the frontier molecular orbitals of the complex were determined by DFT calculations at the B3LYP/def2-TZVP level of theory.

Epalrestat tetrahydrofuran monosolvate: crystal structure and phase transition

The title compound, epalrestat {systematic name: (5Z)-5-[(2E)-2-methyl-3-phenylprop-2-en-1-ylidene]-4-oxo-2-sulfanylidene-1,3-thiazolidine-3-acetic acid}, crystallized as a tetrahydrofuran monosolvate, C15H13NO3S2·C4H8O. Epalrestat, an important drug for diabetic neuropathy, has been reported to exist in polymphic, solvated and co-crystal forms. In the molecule reported here, the phenyl ring is inclined to the rhodamine ring by 22.31 (9)°, and the acetic acid group is almost normal to the rhodamine ring, making a dihedral angle of 88.66 (11)°. In the crystal, pairs of O—H...O hydrogen bonds are observed between the carboxylic acid groups of epalerstat molecules, forming inversion dimers with anR22(8) loop. The dimers are linked by pairs of C—H...O hydrogen bonds, forming chains along [101]. The solvate molecules are linked to the chain by a C—H...O(tetrahydrofuran) hydrogen bond. A combination of thermal analysis and powder X-ray diffraction revealed that title compound desolvated into epalerstat Form II. One C atom of the tetrahydrofuran solvate molecule is positionally disordered and has a refined occupancy ratio of 0.527 (18):0.473 (18).

(RS)-Efonidipine acetone hemisolvate

The asymmetric unit of the title compound, C34H38N3O7P·0.5C3H6O {systematic name: (RS)-2-[phenyl(phenylmethyl)amino]ethyl 5-(5,5-dimethyl-2-oxo-1,3-dioxa-2λ5-phosphacyclohex-2-yl)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carboxylate acetone hemisolvate}, contains oneR-efonidipine molecule, oneS-efonidipine molecule and half of a solvate acetone molecule. In both efonidipine molecules, the six-membered rings of the dioxaphosphinanyl moieties display a chair conformation and the dihydropyridine rings display a flattened boat conformation. In the crystal, N—H...O, C—H...O hydrogen bonds and weak C—H...π interactions link the molecules into a three-dimensional supramolecular structure. A solvent-accessible void of 199 Å3is found in the structure; the contribution of the heavily disordered solvate molecule was suppressed by use of the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst. C71, 9–18].

Crystal structure of chlorido{4,5-dimethoxy-2-[(2,3-η)-2-prop-2-en-1-yl]phenyl-κC1}(piperidine-κN)platinum(II) ethanol monosolvate

In the title compound, [Pt(C11H13O2)Cl(C5H11N)]·C2H5OH, the PtIIcation is pentacoordinated in a distorted square-planar geometry. In the crystal, inversion dimers showing C—H...Cl and C—H...π interactions are further stacked in columns along theaaxisviaC—H...π interactions. The ethanol solvate molecule interacts with neighbouring methoxy groups of methyleugenol through O—H...O hydrogen bonds.

Structural Studies of Iron(III) Complexes with N4O2 Coordination Sphere

The Spin-Crossover (SCO) phenomenon implicates a switchable between a low-spin (LS) diamagnetic state, which is stable at low temperatures and a paramagnetic high-spin state (HS), which is stable at higher temperatures. This transition is generated by an external perturbation such as temperature, pressure or light. In general, the switching process in solid-state systems is controlled by cooperative intermolecular interactions. The correlation of structure with physical properties is crucial to the identification of these interactions and ultimately the understanding of the complex processes that control the SCO phenomenon[1]. With the aim of developing new SCO materials, we carried out the syntheses and crystal structure analysis of seven iron(III) complexes, mixing 5-bromo-salicylaldehyde or 5-chloro-salicylaldehyde and ethylendiamine with iron(III) chloride and/or ammonium hexafluorophosphate solutions by slow diffusion or reflux in methanol or 2-propanol (figure 1). The crystal structures show the iron(III) centre is hexacoordinated (FeN4O2) and the coordination polyhedron can be described as a distorted octahedron formed by the 4 N atoms of the ethylenediamine fragment and 2 hydroxyl O atoms from the salicylaldehyde fragment, this distortion was evaluated at 120 and 298 K, the major distortion were observed in complexes [2]+ PF6–· MeOH, [2]+ PF6–·iPrOH and [1]+ PF6–·MeOH, which is characteristic in HS states, while the complexes [2]+ Cl–·iPrOH, [1]+ PF6–·iPrOH [2]+ and [2]+ClO4–, shows a minor distortion according to LS states. On the other hand, [1]+ClO4– is a SCO complex with a typical geometry for both spin states at 120 K (LS) and 298 K (HS). Finally, we studied the intermolecular interactions using Crystal Explorer Software[2] between the iron complexes, the counterion and/or the solvate molecule, for instance, in the [2]+PF6–·MeOH complex, the most remarkable feature observed are Br···Br intermolecular interactions (figure 2). ACKNOWLEDGMENTS: FONDECYT N01130640, FONDEQUIP EQM120095 and Beca CONICYT folio 21130944

Dichlorido{(2E)-2-[phenyl(pyridin-2-yl)methylidene]hydrazinecarbothioamide}cadmium(II) methanol monosolvate

In the title compound, [CdCl2(C13H12N4S)]·CH3OH, the coordination geometry of the CdIIion is slightly distorted square-pyramidal, as indicated by the τ index of 0.36 (8). The S atom, two N atoms from the pyridyl-azomethine moiety and one of the Cl atoms comprise the basal plane, while the other Cl atom occupies the apical position. The hydrazinecarbothioamide moiety adopts anEconformation with respect to the azomethine bond. The solvate molecule in the crystal lattice plays a major role in interconnecting adjacent molecules by means of O—H...Cl and N—H...O hydrogen-bonding interactions. A supramolecular three-dimensional architecture is sustained in terms of further N—H...Cl and C—H...Cl hydrogen-bonding interactions.

Synthesis, Crystal Structure and Antitumor Study of a Zinc Complex of the 2-Benzoylpyridine Thiosemicarbazone Ligand

A zinc complex of the 2-benzoylpyridine thiosemicarbazone (Hbpt) ligand, Zn(bpt)2 · DMF, has been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The molecular structure has a Zn2+ cation bonded to two perpendicular bpt ligands in a distorted octahedral geometry through two sulfur and four nitrogen atoms. The crystal contains a disordered DMF solvate molecule. Adjacent molecules are interconnected by means of hydrogen bonding generating a 1-D chain structure. The cytotoxic activity measurement indicates that the complex exhibits higher antitumor activity against lung cancer A549 cell lines than the free ligand.