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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]

A series of chelating N N proligands, 3‐(2‐pyridyl)‐5‐alkyl‐1,2,4‐triazoles (HLAlk), where alkyl=methyl, ethyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl was used as building blocks for designing of coordination compounds. Their reaction with an equimolar amount of [PdCl2(CH3CN)2] led to formation of series of six novel palladium complexes [Pd(HLAlk)Cl2], in which ligands are coordinated in the acid form. New proligands and Pd(II) complexes were characterized by IR, 1H and 13C NMR spectroscopy and elemental analysis. The Pd(II) complexes showed an unusual downfield shift in 1H NMR of the aliphatic proton that is the closest to triazole ring, which suggests the C−H...Cl hydrogen bonding, supported by X‐ray data for Pd(HLc−Pr)Cl2 and Pd(HLc−Bu)Cl2. [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]

New Eu(III) and Tb(III) hybrid materials based on N-((1-methyl-3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl)methyl)methacrylamide were synthesized and characterized as potential fluorescent emitters. Complexes of Eu(III) and Tb(III) demonstrate red and green luminescence in the visible region, respectively. The intense broad bands in the region of 270-290nm are related to electronic transitions within pyridine-triazole-containing fragment coordinated to Ln(III) ion. [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]

The title compound, bis-[μ-2,2'-(4 H -1,2,4-triazole-3,5-di-yl)di-acetato]-bis-[di-aqua-copper(II)] dihydrate, [Cu 2 (C 6 H 5 N 3 O 4 ) 2 (H 2 O) 4 ]·2H 2 O, is a dinuclear octa-hedral Cu II triazole-based complex. The central copper atoms are hexa-coordinated by two nitro-gen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxyl-ate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water mol-ecules. Two additional solvent water mol-ecules are linked to the title mol-ecule by O-H⋯N and O⋯H-O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supra-molecular 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%) inter-actions. The crystal studied was twinned by a twofold rotation around [100]., (© Vynohradov et al. 2024.)

This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl 2 (C 12 H 14 N 4 )]·C 3 H 7 NO. The compound crystalizes in the P 2 1 / c space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(H L c-Pe )Cl 2 [H L c-Pe is 2-(3-cyclo-pentyl-1,2,4-triazol-5-yl)pyridine] and one mol-ecule of DMF as a solvate. The Pd atom has a square-planar coordination. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O and C-H⋯N hydrogen bonds, forming layers parallel to the bc plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 41.4%. The contribution of the N⋯H/H⋯N and H⋯O/O⋯H inter-actions is somewhat smaller, amounting to 12.4% and 5%, respectively., (© Dyakonenko et al. 2024.)

The asymmetric unit of the title compound, catena -poly[[[aqua-bis-(pyridine-κ N )cadmium(II)]-μ 2 -4,4'-(1 H -1,2,4-triazole-3,5-di-yl)dibenzoato-κ 4 O , O ': O '', O '''] 4.5-hydrate], {[Cd(C 16 H 9 N 3 O 4 )(C 5 H 5 N) 2 (H 2 O)]·4.5H 2 O} n or {[Cd(bct)(py) 2 (H 2 O)]·4.5H 2 O} n ( I ), consists of a Cd 2+ cation coordinated to one bct 2- carboxyl-ate dianion, two mol-ecules of pyridine and a water mol-ecule as well as four and a half water mol-ecules of crystallization. The metal ion in I possesses a penta-gonal-bipyramidal environment with the four O atoms of the two bidentately coordinated carboxyl-ate groups and the N atom of a pyridine mol-ecule forming the O 4 N equatorial plane, while the N atom of another pyridine ligand and the O atom of the water mol-ecule occupy the axial positions. The bct 2- bridging ligand connects two metal ions via its carb-oxy-lic groups, resulting in the formation of a parallel linear polymeric chain running along the [11] direction. The coordinated water mol-ecule of one chain forms a strong O-H⋯O hydrogen bond with the carboxyl-ate 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 inter-actions between the benzene fragments of the anions as well as between the coordinated pyridine mol-ecules belonging to different chains results in the formation of sheets oriented parallel to the (01) plane. As a result of hydrogen-bonding inter-actions involving the water mol-ecules of crystallization, the sheets are joined together in a three-dimensional network., (© Popovych et al. 2024.)

The title compound, [Cu(H L ) 2 (H 2 O) 2 ] or [Cu(C 4 H 4 N 3 O 2 ) 2 (H 2 O) 2 ], is a mononuclear octa-hedral Cu II complex based on 5-methyl-1 H -1,2,4-triazole-3-carb-oxy-lic acid (H 2 L ). [Cu(H L ) 2 (H 2 O) 2 ] was synthesized by reaction of H 2 L with copper(II) nitrate hexa-hydrate (2:1 stoichiometric ratio) in water under ambient conditions to produce clear light-blue crystals. The central Cu atom exhibits an N 2 O 4 coordination environment in an elongated octa-hedral geometry provided by two bidentate H L - anions in the equatorial plane and two water mol-ecules 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%) inter-actions., (© Petrenko et al. 2024.)

In the title compound [Fe 2 (C 2 O 4 )(C 8 H 8 N 4 ) 4 ](CH 3 C 6 H 4 SO 3 ) 2 ·2.75H 2 O, the two Fe II ions have a highly distorted octa-hedral FeN 4 O 2 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., (© Petrenko et al. 2022.)