Crystal structure and Hirshfeld surface analysis of poly[[tetra-aqua-(µ-1,3,4,7,8,10,12,13,16,17,19,22-dodeca-aza-tetra-cyclo-[8.8.4.13,17.18,12]tetra-cosane-5,6,14,15,20,21-hexaonato)iron(IV)dilithium] tetra-hydrate].

The title compound, [FeLi2(C12H12N12O6)(H2O)4]·4H2O, consists of iron complex anions, lithium cations and water mol-ecules. The complex anion shows a clathrochelate topology. The coordination geometry of the FeIV centre is inter-mediate between a trigonal prism and a trigonal anti-prism. In the crystal, the complex anions are connected through two Li cations into dimers, which are connected by Li-O bonds, forming infinite chains along the b-axis direction.

Crystal structure of polymeric bis-(3-amino-1H-pyrazole)-cadmium dibromide.

The reaction of cadmium bromide tetra-hydrate with 3-amino-pyrazole (3-apz) in ethano-lic solution leads to tautomerization of the ligand and the formation of crystals of the title compound, catena-poly[[di-bromido-cadmium(II)]-bis-(µ-3-amino-1H-pyrazole)-κ2 N 3:N 2;κ2 N 2:N 3], [CdBr2(C3H5N3)2]n or [CdBr2(3-apz)2]n. Its asymmetric unit consists of a half of a Cd2+ cation, a bromide anion and a 3-apz mol-ecule. The Cd2+ cations are coordinated by two bromide anions and two 3-apz ligands, generating trans-CdN4Br2 octa-hedra, which are linked into chains by pairs of the bridging ligands. In the crystal, the ligand mol-ecules and bromide anions of neighboring chains are linked through inter-chain hydrogen bonds into a two-dimensional network. The inter-molecular contacts were qu-anti-fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative qu-anti-tative contributions of the weak inter-molecular contacts.

catena-Poly[[tetra-kis-(3,5-dimethyl-1H-pyrazole-κN 2)copper(II)]-µ2-sulfato-κ2 O:O']: crystal structure and Hirshfeld surface analysis of a CuII coordination polymer.

The title coordination polymer, [Cu(SO4)(C5H8N2)4] n , was synthesized using a one-pot reaction of copper powder, anhydrous copper(II) sulfate and 3,5-dimethyl-1H-pyrazole (Hdmpz) in aceto-nitrile under ambient conditions. The asymmetric unit can be described as a chain consisting of four [Cu(SO4)(Hdmpz)4] formula units that are connected to each other by a µ2-sulfato-bridged ligand. The octa-hedral coordination geometry (O2N4) of all copper atoms is realized by coordination of four pyrazole ligands and two sulfate ligands. Four pyridine-like N atoms of the pyrazole ligands occupy the equatorial positions, while two oxygen atoms of two sulfate ligands are in axial positions. As a result of the sulfate ligand rotation, there is a pairwise alternation of terminal O atoms (which are not involved in coordination to the copper atom) of the SO4 tetra-hedra. The Cu⋯Cu distances within one asymmetric unit are in the range 7.0842 (12)-7.1554 (12) Å. The crystal structure is built up from polymeric chains packed in a parallel manner along the b-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯H (74.7%), H⋯O/O⋯H (14.8%) and H⋯C/C⋯H (8.2%) inter-actions.

Crystal structure and Hirshfeld surface analysis of di-µ-chlorido-bis-[(aceto-nitrile-κN)chlorido-(ethyl 5-methyl-1H-pyrazole-3-carboxyl-ate-κ2 N 2,O)copper(II)].

The title compound, [Cu2Cl4(C5H10N2O2)2(CH3CN)2] or [Cu2(µ2-Cl)2(CH3-Pz-COOCH2CH3)2Cl2(CH3CN)2], was synthesized using a one-pot reaction of copper powder, copper(II) chloride dihydrate and ethyl 5-methyl-1H-pyrazole-3-carboxyl-ate (CH3-Pz-COOCH2CH3) in aceto-nitrile under ambient conditions. This complex consists of discrete binuclear mol-ecules with a {Cu2(µ2-Cl)2} core, in which the Cu⋯Cu distance is 3.8002 (7) Å. The pyrazole-based ligands are bidentate coordinated, leading to the formation of two five-membered chelate rings. The coordination geometry of both copper atoms (ON2Cl3) can be described as distorted octa-hedral on account of the aceto-nitrile coordination. A Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯H (40%), H⋯Cl/Cl⋯H (24.3%), H⋯O/O⋯H (11.8%), H⋯C/C⋯H (9.2%) and H⋯N/N⋯H (8.3%) inter-actions.

Crystal structure of bis-{µ-2-[bis-(2-hy-droxy-eth-yl)amino]-ethano-lato}bis-(µ-3,5-di-methyl-pyrazolato)tricopper(II) dibromide sesquihydrate.

In the title bicyclic trinuclear pyrazolate amino-alcohol complex, [Cu3(C5H7N2)2(C6H14NO3)2]Br2·1.5H2O, the central Cu atom lies on a center of symmetry and is involved in the formation of two five-membered rings. It has a coordination number of 4, is in a distorted tetra-hedral environment and is connected by the bridging oxygen atoms of the deprotonated OH groups of different amino-alcohol groups, and by the N atoms of deprotonated di-methyl-pyrazole ligands. The peripheral Cu atom is in a trigonal-bipyramidal coordination environment formed by the nitro-gen atom of the deprotonated bridging di-methyl-pyrazole unit, the bridging oxygen atom of the deprotonated OH group, two oxygen atoms of the protonated hy-droxy groups and the nitro-gen atom of tri-ethano-lamine. One of the C atoms and the Br- anion were found to be disordered over two positions with occupancy factors of 0.808 (9):0.192 (9) and 0.922 (3):0.078 (3), respectively.

Crystal structure of di-chlorido-1κCl,2κCl-(µ2-3,5-dimethyl-1H-pyrazolato-1κN 2:2κN 1)(3,5-dimethyl-1H-pyrazole-2κN 2){µ-2-[(2-hy-droxy-eth-yl)amino-1κ2 N,O]ethano-lato-1:2κ2 O:O}dicopper(II).

The title compound, [Cu2(C5H7N2)(C4H10NO2)Cl2(C5H8N2)], is a pyrazolate amino-alcohol complex which contains two di-methyl-pyrazole mol-ecules in monodentate and bidentate-bridged coordination modes and a monodeproton-ated di-ethano-lamine mol-ecule. Both copper atoms are involved in the formation of non-planar five-membered chelate rings. One Cu atom is in a distorted tetra-hedral environment formed by the pyridine nitro-gen atom of the protonated di-methyl-pyrazole mol-ecule, the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the bridged O atom of the monodeprotonated di-ethano-lamine. The second Cu atom has an inter-mediate environment between trigonal bipyramidal and square pyramidal, formed by the N atom of the deprotonated bridged di-methyl-pyrazole, the Cl atom and the N atom of the amino-alcohol, and two O atoms of the deprotonated and protonated OH groups. In the crystal, N-H⋯Cl hydrogen bonds link the molecules into anti-symmetric chains running along the a-axis direction. Adjacent chains are connected by O-H⋯O hydrogen bonds involving the hydroxyl group as donor.

Synthesis, crystal structure, spectroscopic features and Hirshfeld surfaces of 2-methyl-3-[(2-methyl-phen-yl)carbamo-yl]phenyl acetate.

The title compound, C17H17NO3, was synthesized, characterized by IR spectroscopy and its crystal structure was determined from single-crystal diffraction data. The asymmetric unit contains two mol-ecules, which adopt different conformations. In one mol-ecule, the acet-oxy and the terminal 2-methyl-phenyl groups are positioned on opposite sides of the plane formed by the central benzene ring, whereas in the other mol-ecule they lie on the same side of this plane. In the crystal, the mol-ecules are linked through strong N-H⋯O hydrogen bonds into chains along [010]. Hirshfeld surface analysis and fingerprint plots were used to investigate the inter-molecular inter-actions in the solid state.

Crystal structure and Hirshfeld surface analysis of (E)-2,4-di-tert-butyl-6-[(3-chloro-4-methyl-phenyl-imino)-meth-yl]phenol.

The title Schiff base compound, C22H28ClNO, shows mirror symmetry with all its non-H atoms, except the tert-butyl groups, located on the mirror plane. There is an intra-molecular O-H⋯N hydrogen bond present forming an S(6) ring motif. In the crystal, the mol-ecules are connected by C-H⋯π inter-actions, generating a three-dimensional supra-molecular structure. Hirshfeld surface analysis and two dimensional fingerprint plots were used to analyse the inter-molecular inter-actions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (68.9%) and C⋯H/H⋯C (11.7%) inter-actions.

Combined analysis of chemical bonding in a Cu(II) dimer using QTAIM, Voronoi tessellation and Hirshfeld surface approaches.

Interaction of 1-(1H-pyrazol-5-yl)ethanone oxime (H2PzOx) with copper(II) chloride in the presence of pyridine afforded a binuclear discrete [Cu2(HPzOx)2Cl2py2] complex, which was characterized by Fourier transform-IR and electron paramagnetic resonance (EPR) spectra, magnetochemistry and high-resolution X-ray diffraction experiments. Multipole refinement of X-ray diffraction data and density-functional theory (DFT) calculations of an isolated molecule allowed charge and spin distributions to be obtained for this compound. Magnetochemistry data, EPR spectra and DFT calculations of an isolated molecule show antiferromagnetic coupling between copper(II) ions. The spin distribution suggests an exchange pathway via the bridging pyrazole ring in the equatorial plane of the CuN4Cl coordination polyhedron, thus providing support for the classical superexchange mechanism; the calculated value of the magnetic coupling constant -2J is equal to 220 cm(-1), which compares well with the experimental value of 203 ±â€…2 cm(-1). Chemical connectivity was derived by Bader's 'quantum theory of atoms in molecules' and compared with Voronoi tessellation and Hirshfeld surface representations of crystal space. All methodologies gave a similar qualitative and semi-quantitative description of intra- and intermolecular connectivity.

[Di-aqua-sesqui(nitrato-κO)hemi(perchlorato-κO)copper(II)]-µ-{bis-[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide}-[tri-aqua-(perchlorato-κO)copper(II)] nitrate monohydrate.

In the binuclear title complex, [Cu2(ClO4)1.5(NO3)1.5(C18H16N6Se)(H2O)5]NO3·H2O, both Cu(II) ions are hexa-coordinated by O and N atoms, thus forming axially elongated CuO4N2 octa-hedra. The equatorial plane of each octa-hedron is formed by one chelating pyrazole-pyridine fragment of the organic ligand and two water mol-ecules. The axial positions in one octa-hedron are occupied by a water mol-ecule and a monodentately coordinated perchlorate anion, while those in the other are occupied by a nitrate anion and a disordered perchlorate/nitrate anion with equal site occupancy. The pyrazole-pyridine units of the organic selenide are trans-oriented to each other with a C-Se-C angle of 96.01 (14)°. In the crystal, uncoordinated nitrate anions and the coordinating water mol-ecules are involved in O-H⋯O and N-H⋯O hydrogen bonds, forming a bridge between the pyrazole group and the coordinating water mol-ecules. Further O-H⋯O hydrogen bonds between the complex mol-ecules and a π-π stacking inter-action with a centroid-centroid distance of 3.834 (4) Šare also observed.

Bis{4-[(3,5-dimethyl-1H-pyrazol-4-yl)selan-yl]-3,5-dimethyl-1H-pyrazol-2-ium} chloride monohydrate.

In the title compound, 2C(10)H(15)N(4)Se(+)·Cl(-)·OH(-), a singly protonated mol-ecule of the organic selenide participates in hydrogen bonding with neighboring mol-ecules, forming zigzag chains along [001]. The molecule adapts a cis bridging mode with a C-Se-C angle of 102.13 (15)°. π-π stacking inter-actions are observed between the closest pyrazole rings of neighboring chains [centroid-centroid distance = 3.888 (1) Å] and hydrogen bonding occurs through bridging chloride anions and hydroxide groups. Additionally, O-H⋯Cl hydrogen bonds are formed.

(3-Acetyl-5-carboxyl-ato-4-methyl-1H-pyrazol-1-ido-κ(2) N (1),O (5))aqua-[(pyridin-2-yl)methanamine-κ(2) N,N']copper(II).

In the title compound, [Cu(C7H6N2O3)(C6H8N2)(H2O)], the Cu(II) ion is in a distorted square-pyramidal N3O2 environment formed by two bidentate chelating ligands in the equatorial coordination sites and one water mol-ecule in the apical direction. In the crystal, O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds link the complex mol-ecules into a three-dimensional supra-molecular network.

[Aqua-bis-(nitrato-κO)copper(II)]-µ-{bis-[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl]selenide}-[diaqua-(nitrato-κO)copper(II)] nitrate monohydrate.

In the title binuclear complex, [Cu2(NO3)3(C18H16N6Se)(H2O)3]NO3·H2O, the Cu(II) ions are penta-coordinated in a tetra-gonal-pyramidal geometry. In both cases, the equatorial planes are formed by a chelating pyrazole-pyridine group, a water mol-ecule and a nitrate O atom, whereas the apical positions are occupied by a water mol-ecule for one Cu(II) ion and a nitrate O atom for the other. The organic selenide ligand adopts a trans configuration with respect to the C-Se-C plane. Numerous inter-molecular O-H⋯O and N-H⋯O hydrogen bonds between the coordinating and lattice water mol-ecules, nitrate anions and pyrazole groups are observed. π-π stacking inter-actions between the pyridine rings [averaged centroid-centroid distance = 3.652 (5) Å] are also present. The lattice water molecule is equally disordered over two sets of sites.

(Tris{2-[(5-hy-droxy-pyridin-2-yl-κN)methyl-idene-imino-κN]eth-yl}amine)-zinc dinitrate.

In the complex cation of the title compound, [Zn(C(24)H(27)N(7)O(3))](NO(3))(2), the tripodal tris-{[2-(5-hy-droxy-pyridin-2-yl)methyl-idene-imino]-eth-yl}amine ligand is coordin-ated to the Zn atom through the three pyridine and three imino N atoms. The coordination sphere of the Zn atom is based on an octahedron with a significant distortion towards trigonal prismatic, the twist angle being 45.58 (9)°. The crystal packing is formed by L and D anti-podes arranged in layers disposed parallel to the b axis. Strong O-H⋯O hydrogen bonding exists between the hy-droxy groups of the ligand and the nitrate anion.

1-{3-[1-(Hydroxyimino)ethyl]-4-methyl-1H-pyrazol-5-yl}ethanone.

In the title compound, C(8)H(11)N(3)O(2), the oxime and the acetyl groups adopt a transoid conformation, while the pyrazole H atom is localized in the proximity of the acetyl group and is cis with respect to the acetyl O atom. In the crystal, dimers are formed as the result of hydrogen-bonding inter-actions involving the pyrazole NH group of one mol-ecule and the carbonyl O atom of another. The dimers are associated into sheets via O-H⋯N hydrogen bonds involving the oxime hydroxyl and the unprotonated pyrazole N atom, generating a macrocyclic motif with six mol-ecules.

cyclo-Tetra-kis(µ-3-acetyl-4-methyl-1H-pyrazole-5-carboxyl-ato-κN,O:N,O)tetra-kis[aqua-copper(II)] tetra-deca-hydrate.

The title compound, [Cu(4)(C(7)H(6)N(2)O(3))(4)(H(2)O)(4)]·14H(2)O, a tetra-nuclear [2 × 2] grid-type complex with S4 symmetry, contains four Cu(II) atoms which are bridged by four pyrazole-carboxyl-ate ligand anions and are additionally bonded to a water molecule. Each Cu(II) atom is coordinated by two O atoms of the carboxyl-ate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carb-oxy-lic acid and one O atom of a water mol-ecule. The geometry at each Cu(II) atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O-H⋯O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.

3,5-Dimethyl-4-nitroso-1H-pyrazole.

In the unit cell of the title compound, C(5)H(7)N(3)O, there are two conformers (A and B) which differ in the position of the oxime group with respect to the protonated pyrazole nitro-gen (trans in the A conformer and cis in the B conformer) and in the geometric parameters. The oxime group exists in the nitroso form in both conformers. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O and N-H⋯N hydrogen bonds into zigzag-like chains along the b axis.

Dibromidobis(3,5-dimethyl-1H-pyrazole-κN)cobalt(II).

In the mononuclear title complex, [CoBr(2)(C(5)H(8)N(2))(2)], the Co(II) atom is coordinated by two N atoms from two monodentate 3,5-dimethyl-pyrazole ligands and two Br atoms in a highly distorted tetra-hedral geometry. In the crystal, the complex mol-ecules are linked by inter-molecular N-H⋯Br hydrogen bonds into chains along [101]. An intra-molecular N-H⋯Br hydrogen bond is also present.

catena-Poly[[[aqua-copper(II)]bis-[µ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide]] bis-(tetra-fluorido-borate) bis-(triphenyl-phosphine oxide) monohydrate].

The title compound, {[Cu(C(10)H(14)N(4)Se)(2)(H(2)O)](BF(4))(2)·2C(18)H(15)PO·H(2)O}(n), has a polymeric structure where each Cu(II) ion adopts a square-pyramidal coordination constituted by four N atoms of pyrazole moieties in the equatorial plane and an axial O atom of a water mol-ecule. A pair of bis-(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridges the Cu(II) centres into a chain extending along the c axis. The water mol-ecules, anions and triphenyl-phosphine oxide mol-ecules are involved in inter-molecular hydrogen bonding, which links the chains into a three-dimensional network.

catena-Poly[[[aqua-copper(II)]-bis-[µ-bis-(3,5-dimethyl-1H-pyrazol-4-yl) selenide-κN:N]] dichloride monohydrate].

In the title compound, {[Cu(C(10)H(14)N(4)Se)(2)(H(2)O)]Cl(2)·H(2)O}(n), the Cu(II) ion, lying on a twofold rotation axis, has a square-pyramidal geometry constituted by four N atoms of pyrazolyl groups in the basal plane and an apical O atom of a water mol-ecule. A pair of bis-(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridge the Cu centers into a polymeric double-chain extending along [001]. The chloride anions are involved in inter-molecular N-H⋯Cl and O-H⋯Cl hydrogen bonds, which link the chains into a three-dimensional network.