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Two enanti­omeric non-heme iron complexes [Fe(R,R-BPMCN)(CH3CN)2](SbF6)2 and [Fe(S,S-BPMCN)(CH3CN)2](SbF6)2 (BPMCM = N,N′-dimethyl-N,N′-bis­(pyridin-2-ylmeth­yl)-cyclo­hexane-1,2-di­amine, C22H28N4) were obtained in parallel syntheses starting from the enanti­omerically pure R,R and S,S BPMCN ligands. The FeII cations have a distorted octa­hedral FeN6 geometry formed by a chelating N,N,N,N-tetra­dentate BPMCN ligand and two mol­ecules of aceto­nitrile. The ligand adopts a cis-α topology with the two pyridine groups coordinated trans to each other. In the crystals, a system of C—H⋯F hydrogen bonds links the cations to the hexa­fluoro­anti­monate anions, resulting in a three-dimensional architecture. [ABSTRACT FROM AUTHOR]

The structures of the title compounds 2-hy­droxy-N′-methyl­acetohydrazide, 1, and 2-hy­droxy-N-methyl­acetohydrazide, 2, both C3H8N2O2, as regioisomers differ in the position of the methyl group relative to the N atoms in 2-hy­droxy-acetohydrazide. In the structure of 1, the 2-hy­droxy-acetohydrazide core [OH—C—C(=O)—NH—NH] is almost planar and the methyl group is rotated relative to this plane. As opposed to 1, in the structure of 2 all non-hydrogen atoms lie in the same plane. The hydroxyl and carbonyl groups in structures 1 and 2 are in trans and cis positions, respectively. The methyl amino group and carbonyl group are in the cis position relative to the C—N bond in structure 1, while the amino group and carbonyl group are in the trans position relative to the C—N bond in stucture 2. In the crystal, mol­ecules of 1 are linked by N—H⋯O and O—H⋯N inter­molecular hydrogen bonds, forming layers parallel to the ab crystallographic plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 55.3%. The contribution of the H⋯O/O⋯H inter­action is somewhat smaller, amounting to 30.8%. In the crystal, as a result of the inter­molecular O—H⋯O hydrogen bonds, mol­ecules of 2 form dimers, which are linked by N—H⋯O hydrogen bonds and a three-dimensional supra­molecular network The major contributors to the Hirshfeld surface are H⋯H (58.5%) and H⋯O/O⋯H contacts (31.7%). [ABSTRACT FROM AUTHOR]

The title compound, bis[μ-2,2′-(4H-1,2,4-triazole-3,5-diyl)diacetato]bis[diaquacopper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octahedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitrogen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxylate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water molecules. Two additional solvent water molecules are linked to the title molecule by O—H⋯N and O⋯H—O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supramolecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) interactions. The crystal studied was twinned by a twofold rotation around [100]. [ABSTRACT FROM AUTHOR]

In the title complex, [U(C10H7N3O3)O2(CH3OH)]n, the UVI cation has a typical penta­gonal–bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hy­droxy­phen­yl)-1H-1,2,4-triazol-3-yl]acetic acid ligand, a carboxylate O atom of the symmetry-related ligand and the O atom of the methanol mol­ecule [U—N/Oeq 2.256 (4)–2.504 (5) Å]. The axial positions are occupied by two oxide O atoms. The equatorial atoms are almost coplanar, with the largest deviation from the mean plane being 0.121 Å for one of the O atoms. The benzene and triazole rings of the tetra­dentate chelating–bridging ligand are twisted by approximately 21.6 (2)° with respect to each other. The carboxyl­ate group of the ligand bridges two uranyl cations, forming a neutral zigzag chain reinforced by a strong O—H⋯O hydrogen bond. In the crystal, adjacent chains are linked into two-dimensional sheets parallel to the ac plane by C/N—H⋯N/O hydrogen bonding and π–π inter­actions. Further weak C—H⋯O contacts consolidate the three-dimensional supra­molecular architecture. In the solid state, the compound shows a broad medium intensity LMCT transition centred around 463 nm, which is responsible for its red colour. [ABSTRACT FROM AUTHOR]

The new palladium(II) complex, [Pd(C16H16N4O3)2](CF3COO)2·2CF3COOH, crystallizes in the triclinic space group P⥘ with the asymmetric unit containing half the cation (PdII site symmetry Ci), one tri­fluoro­actetate anion and one co-crystallized tri­fluoro­acetic acid mol­ecule. Two neutral chelating 2-[5-(3,4,5-tri­meth­oxy­phen­yl)-4H-1,2,4-triazol-3-yl]pyridine ligands coordinate to the PdII ion through the triazole-N and pyridine-N atoms in a distorted trans-PdN4 square-planar configuration [Pd—N 1.991 (2), 2.037 (2) Å; cis N—Pd—N 79.65 (8), 100.35 (8)°]. The complex cation is quite planar, except for the methoxo groups (δ = 0.117 Å for one of the C atoms). The planar configuration is supported by two intra­molecular C—H⋯N hydrogen bonds. In the crystal, the π–π-stacked cations are arranged in sheets parallel to the ab plane that are flanked on both sides by the tri­fluoro­acetic acid–tri­fluoro­acetate anion pairs. Apart from classical N/O—H⋯O hydrogen-bonding inter­actions, weak C—H⋯F/N/O contacts consolidate the three-dimensional architecture. Both tri­fluoro­acetic moieties were found to be disordered over two resolvable positions with a refined occupancy ratio of 0.587 (1):0.413 (17) and 0.530 (6):0.470 (6) for the protonated and deprotonated forms, respectively. [ABSTRACT FROM AUTHOR]

The title compound, N¹, N²-dimethylethanedihydrazide, C4H10N4O2, was obtained by the methylation of oxalyl dihydrazide protected with phthalimide. The molecule is essentially non-planar with a dihedral angle between the two planar hydrazide fragments of 86.5 (2)°. This geometry contributes to the formation of a multi-contact three-dimensional supramolecular network via C--H...O, N--H...O and N--H...N hydrogen bonds. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, catena-poly[[[aqua­bis­(pyridine-κN)cadmium(II)]-μ2-4,4′-(1H-1,2,4-triazole-3,5-di­yl)dibenzoato-κ4O, O′:O′′, O′′′] 4.5-hydrate], {[Cd(C16H9N3O4)(C5H5N)2(H2O)]·4.5H2O}n or {[Cd(bct)(py)2(H2O)]·4.5H2O}n (I), consists of a Cd2+ cation coordinated to one bct2-carboxyl­ate dianion, two mol­ecules of pyridine and a water mol­ecule as well as four and a half water mol­ecules of crystallization. The metal ion in I possesses a penta­gonal-bipyramidal environment with the four O atoms of the two bidentately coordinated carboxyl­ate groups and the N atom of a pyridine mol­ecule forming the O4N equatorial plane, while the N atom of another pyridine ligand and the O atom of the water mol­ecule occupy the axial positions. The bct2-bridging ligand connects two metal ions via its carb­oxy­lic groups, resulting in the formation of a parallel linear polymeric chain running along the [1\overline{1}1] direction. The coordinated water mol­ecule of one chain forms a strong O--H...O hydrogen bond with the carboxyl­ate O atom of a neighboring chain, leading to the formation of double chains with a closest distance of 5.425(7)Å between the cadmium ions belonging to different chains. Aromatic π-π stacking inter­actions between the benzene fragments of the anions as well as between the coordinated pyridine mol­ecules belonging to different chains results in the formation of sheets oriented parallel to the (\overline{1}01) plane. As a result of hydrogen-bonding inter­actions involving the water mol­ecules of crystallization, the sheets are joined together in a three-dimensional network. [ABSTRACT FROM AUTHOR]

The title compound, [Cu(HL)2(H2O)2] or [Cu(C4H4N3O2)2(H2O)2], is a mononuclear octahedral CuII complex based on 5-methyl-1H-1,2,4-triazole-3-carboxylic acid (H2L). [Cu(HL)2(H2O)2] was synthesized by reaction of H2L with copper(II) nitrate hexahydrate (2:1 stoichiometric ratio) in water under ambient conditions to produce clear light-blue crystals. The central Cu atom exhibits an N2O4 coordination environment in an elongated octahedral geometry provided by two bidentate HL- anions in the equatorial plane and two water molecules in the axial positions. Hirshfeld surface analysis revealed that the most important contributions to the surface contacts are from H. . .O/O. . .H (33.1%), H. . .H (29.5%) and H. . .N/N. . .H (19.3%) interactions. [ABSTRACT FROM AUTHOR]

The title compound, bis[μ-3-ethyl-5-(pyridin-2-yl)-1H-1,2,4-triazol-1-ido]bis-[acetato(dimethylformamide)copper(II)], [Cu2(C9H9N4)2(C2H3O2)2(C3H7NO)2] or [Cu2(LEt)2(OAc)2(dmf)2], is a triazolate complex, which contains two 3-(2-pyridyl)-5-ethyl-triazolates (LEt)- in bidentate-bridged coordination modes. Both copper atoms are involved in the formation of a planar six-membered metallocycle Cu-[N-N]2-Cu. The inversion center of the complex is located at the mid-point of the Cu...Cu vector. Each CuII atom has a distorted trigonal-bipyramidal environment formed by the three nitrogen atoms of the deprotonated bridging 3-(2-pyridyl)-5-ethyl-triazolate unit, oxygen atoms of the OAc- group and dmf molecule. In the crystal, C-H...O hydrogen bonds link the molecules into chains running along the c-axis direction. [ABSTRACT FROM AUTHOR]

In the title compound [Fe2(C2O4)(C8H8N4)4](CH3C6H4SO3)2·2.75H2O, the two FeII ions have a highly distorted octa­hedral FeN4O2 environment formed by two bidentate triazole-based chelating ligands and a bis-bidentate oxalate bridging anion that connects the metal ions. Stabilization within the crystal structure is provided via a system of O--H⋯O and N--H⋯O hydrogen bonding, which determines the formation of a two-dimensional architecture along the a-axis direction. [ABSTRACT FROM AUTHOR]

New representatives of [1,2,4]triazolo[1,5‐a]pyridine‐8‐carbonitriles were synthesized via the condensation of β‐diketones or β‐dialdehydes and characterized using MS spectrometry, 1H, 13C and, 19F NMR and IR spectroscopy. Crystal structures of two compounds were established using X‐ray analysis and showed that title compounds are prone to the formation of planar molecules. The absence of band responsible for CN stretching vibration in trifluoromethyl‐containing compounds was explained using the DFT calculations method, which also showed a significant influence of fluorines introducing on the energy gap between HOMO and LUMO. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pt(II) complexes with 3-(2-pyridyl)-N1,2-methyl-1,2,4-triazoles were prepared. • X-Ray showed square planar environment of the central atom in PtL1Cl 2 and PtL2Cl 2. • Complexes partially decompose in DMSO solution. • PtL1Cl 2 and PtL 2 Cl 2 are moderately cytotoxic against A2780 and A2780cis cell lines. The present work describes the synthesis, investigation and in vitro cytotoxicity of Pt(II) complexes with 3-(2-pyridyl)-N1-methyl-1,2,4-triazole (L1) and 3-(2-pyridyl)–N2-methyl-1,2,4-triazole (L2). The crystal structures of PtL1Cl 2 and PtL2Cl 2 were established using X-Ray analysis, which revealed the square-planar PtN 2 Cl 2 coordination geometry for the central metal ion. High-resolution mass spectrometry (HRMS), as well as one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy showed stability of the investigated complexes in DMF solution, in contrast to DMSO, where species were shown to partially dissociate. The cytotoxicity of the investigated compounds was determined by the colorimetric MTT assay against two human cancer cell lines, including cisplatin-sensitive human ovarian adenocarcinoma A2780 cells (IC 50 = 26 ± 5 and 6.1 ± 0.6 for PtL1Cl 2 and PtL2Cl 2 correspondingly) and their cisplatin-resistant A2780cis analogue (IC 50 = 24 ± 2 and 20 ± 3 for PtL1Cl 2 and PtL2Cl 2 correspondingly). [ABSTRACT FROM AUTHOR]

Zinc and cadmium complexes, ML2(NO3)2 (L = N-methyl-C-(2-pyridyl)nitrone) were synthesized and characterized by means of X-ray diffraction crystallography and IR and NMR spectroscopy. The organic ligands in the complexes are coordinated via the oxygen atom of the nitrone group and the nitrogen atom of the pyridine moiety. The coordination environment of the central atoms is a distorted octahedron. The bond lengths and angles of the complexes were calculated using the DFT method with B3LYP functional. Theoretical studies revealed that the geometric parameters are in agreement with the experimental data. The fluorescent properties for the zinc and cadmium complexes were investigated at room temperature. [ABSTRACT FROM AUTHOR]

• A novel nickel(II) complex was synthesized via a template reaction. • The central Ni atom exhibits square planar coordination. • Calculated (DFT) geometry aligns well with experimental (X-ray diffraction) values. • The compound is an excellent candidate for nonlinear optical material. • Molecular docking suggests that the complex has anti-Alzheimer's potential. The title compound, [Ni(C 11 H 14 N 10 O 3)]·2H 2 O, was synthesized through a template reaction involving 1-methyl-1H-1,2,4-triazole-5-carbohydrazide and formaldehyde in the presence of Ni(II) chloride. The ligand is formed through the template binding of two hydrazide-containing fragments with three formaldehyde molecules. Coordinating in a tetradentate manner, the ligand forms three fused chelate rings, and the central Ni atom exhibits square planar coordination. In the crystals, complex molecules interconnect via hydrogen bonds with water molecules, forming chains in the [11ī] crystallographic direction. DFT analysis indicates that the complex molecule demonstrates a noteworthy electron-donating ability and exhibits non-linear optical (NLO) activity. Molecular docking suggests that the title compound has the potential to function as an anti-Alzheimer's agent. [Display omitted] [ABSTRACT FROM AUTHOR]

• Novel copper(II) complexes of 3-(2-pyridyl)-1,2,4-triazole were prepared and well characterized. • Molar metal to ligand ratio affects the nuclearity of a polynuclear associate. • Complexes were determined using X-rays and spectroscopic techniques. • Magnetic properties reflect Cu-Cu antiferromagnetic interaction. The synthesis, crystal structure, spectroscopic and magnetic properties of binuclear [Cu 2 (L) 2 (SO 4)(H 2 O) 3 ·3H 2 O (4a) and tetranuclear [Cu 4 (HL) 2 (L) 4 (DMF) 2 (SO 4) 2 ·DMF (4b) copper(II) complexes were reported (where HL is 3-(pyridine-2-yl)-1,2,4-triazole). Potentiometric titrations, ESI-MS and spectrophotometric studies of complex formation in MeOH/H 2 O solutions indicated the presence of monomeric [CuHL]2+, dinuclear [Cu 2 L 2 2+ and [Cu 2 L 2 (OH)]+, and trinuclear [Cu 2 L 3 + and [Cu 2 L 3 (OH)] species. The small N,N-nucleating ligand HL leads to a supramolecular formation of the complexes. The ligand comprises a triazole moiety substituted by pyridine group, strategically located to form chelate metalocycles. The basis of both complexes is two metal centres bridged via N 1 –N 2 diazine grouping of a triazole ring. For complex 4b two HL coordinate in acidoform via N Py and N 4 of azole moiety as well. There are significant differences in the polyhedrons, namely nuclearity and Cu...Cu separations. Complexes were characterized by elemental analysis, mass-spectrometry, IR- spectroscopy and X-ray analysis. Magnetic measurements revealed that both compounds exhibit antiferromagnetic interaction. The magnetic susceptibility data were interpreted on the basis of the spin Hamiltonian in the temperature range (2–300 K) using the dinuclear (4a: J 1 = −52.41 cm−1) and tetranuclear (4b: J 1 = −53.10 cm−1 to J 2 = −0.14 cm−1) models. [ABSTRACT FROM AUTHOR]