Ni(II) complexes with optically active bis(menthane), pinano-para-menthane ethylenediaminodioximes and pinano-para-menthane, bis(pinane) propylenediaminodioximes: Synthesis, structures, and properties

Reactions of Ni(NO₃)₂ · 6H₂O) in EtOH(iso-PrOH) with optically active bis(menthane) ethylene-diaminodioxime (H₂L¹), pinano-para-menthane ethylenediaminodioxime (H₂L²), pinano-para-menthane propylenediaminodioxime (H₂L³) and bis(pinane) propylenediaminodioxime (H₂L⁴) were used to synthesize [Ni(H₂L¹)NO₃[NO₃ · 2H₂O (I), [Ni(HL²)]NO₃ (II), [Ni(HL³)]NO₃ (III), and [Ni(HL⁴)]NO₃ (IV). X-ray diffraction study of paramagnetic complex I (μ_eff = 3.04 μB and diamagnetic complexes II and III revealed their ionic structures. A distorted octahedral polyhedron N₄O₂ in the cation of complex I is formed by the N atoms of tetradentate cycle-forming ligand, i.e., the H₂L¹ molecule, and the O atoms of the NO ₃ ^? anion acting as a bidentate cyclic ligand. In the cations of complexes II and III, containing a pinane fragment, the coordination core NiN₄ has the shape of a distorted square formed on coordination of tetradentate cycle-forming ligands, i.e., anions of the starting dioximes. The structure of diamagnetic complex IV is likely to be similar to the structures of complexes II and III.     

Synthesis and structure of new Zn(II) and Co(II) coordination polymers with 1,3,5-benzenetricarboxylic acid

Two new Zn(II) and Co(II) compounds obtained by reactions of tetrafluoroborates of these metals with 1,3,5-benzenetricarboxylic (trimesic) acid (H₃Btc) and 1,3-bis(pyridyl)propane (Bpp) as an additional ligand were studied by X-ray diffraction. The formation of coordination polymers of various dimensionality, {[Zn₄(Bpp)₄(HBtc)₃((Me)Btc)]{(Me)₂HBtc} · 2H2O} _n (I), 1D, and {[Co₄(μ₃-OH)₂(Btc)₂(H₂O)₈] · 4(H₂O)} _n (II), 2D (CIF files CCDC no. 1552167 (I), 1552168 (II)) was demonstrated. Since H3Btc is partially methylated during the reaction, in I, this acid is stabilized in three forms: HBtc^2–, (Me)Btc^2–, and (Me)₂HBtc. The tetrahedral Zn(II) coordination polyhedron is formed by the N₂O₂ set of donor atoms: the O atoms belong to two different carboxylate ligands, HBtc^2– and (Me)Btc^2–, while the N atoms belong to two Bpp ligands. In II, the Bpp ligand is not incorporated in the complex and H₃Btc is coordinated to five metal atoms as a triply deprotonated ligand. Two carboxyl groups are coordinated to Co atoms as bidentate bridging ligands, while the third group is monodentate. The octahedral coordination polyhedra of Co(II) atoms in II are supplemented by terminal water molecules and μ₃-bridging OH^– groups.     

Mono- and dinuclear vanadium complexes with the pentadentate schiff base 2,6-diacetylpyridine bis(nicotinylhydrazone): Synthesis and structures

A reaction between VOSO₄, 2,6-diacetylpyridine, and nicotinohydrazide in a molar ratio of 1: 1: 2 afforded two complexes differing in both color and crystal shape as well as in chemical composition and molecular structure. The compositions and structures of the vanadium complexes were determined by IR spectroscopy and X-ray diffraction (CIF files CCDC_nos. 1411235 (I) and 1411236 (II)). These complexes can be formulated as [V ₂ ^II (H₂L)₂](NO₃)₄ ? H₂O (I) and [V^IV(=O)(H₂L)(SO₄)] ? 5H₂O (II), where H₂L is 2,6-diacetylpyridine bis(nicotinylhydrazone). Complex I consists of centrosymmetric dinuclear complex cations [V₂(H₂L)₂]⁴⁺, NO ₃ ^- anions, and crystal water molecules in a ratio of 1: 4: 1; complex II is built from molecular V(IV) complexes and crystal water molecules in a ratio of 1: 5. The coordination polyhedron of the metal atom in I is a tetragonal pyramid made up of the electron-donating atoms N₃O₂ of two ligands H₂L. The coordination polyhedron of the metal atom in II is a pentagonal bipyramid made up of the electron-donating atoms N₃O₂ of one neutral five-coordinate ligand H₂L and two O atoms coming from the oxo ligand and the SO ₄ ^2- anion coordinated in a monodentate fashion.     

Synthesis and crystal structure of zinc(II) and manganese(II) complexes of 2-(diphenylacetyl)indandione-1,3

Zinc(II) and manganese(II) complexes of 2-(diphenylacetyl)indandione-1,3 (HL) were synthesized. Crystals of [M(DMSO)₂L₂] · CHCl₃, where M= Zn^(II) (I) and Mn^(II) (II), obtained from chloroform plus dimethyl sulfoxide (DMSO) mixture were found to be isostructural based on the similarity of their unit cell parameters and unit cell volumes. The crystals are triclinic, Z = 2, space group P \(\bar 1\); a = 10.422(1) Å, b = 11.929(1) Å, c = 20.429(1) Å, α = 73.616(1)°, β = 85.095(1)°, γ = 77.586(1)° for complex I; a = 10.436(1) Å, b = 12.297(1) Å, c = 19.924(2) Å, α = 78.138(2)°, β = 87.625(2)°, γ = 82.048(2)° for complex II. X-ray structural analysis of complex I was carried out. For complex II, the structure was not refined because all of its atoms are each disordered over three to five positions. The two DMSO molecules in complex I coordinate the central metal atoms in the monodentate mode via their donor oxygen atoms to occupy an axial position and an equatorial position in an octahedral polyhedron. The other four positions are occupied by the four oxygen atoms of the two deprotonated ligands L^? coordinated in the bidentate-cyclic mode. The outer sphere of complex I contains the solvating chloroform molecule.     

Synthesis and properties of copper(II) complexes with a chiral dioxatetraazamacrocyclic ligand based on a natural monoterpene, (+)-3-carene

The copper(II) compounds [CuL](NO₃)₂ · H₂O (I), [CuL](ClO₄)₂ · H₂O (II), CuLCl₂ · 3H₂O (III), and CuLBr₂ · 4H₂O (IV), where L is a chiral dioxatetraazamacrocyclic ligand based on the natural monoterpene (+)-3-carene, have been synthesized. According to IR and EPR spectroscopy, L acts as a tetradentate chelating ligand coordinated through the N atoms of the NH and C=N groups. The NO ₃ ^? anions in I and the ClO ₄ ^? anions in II are outer-sphere. I and II have a planar coordination core CuN₄, III has a CuN₄ClO coordination core, and IV has a CuN₄Br₂ coordination core.     

Copper(II) coordination compounds with 8-quinolinaldehyde semicarbazone: Synthesis and structure

A series of compounds of the general formula Cu(HL)X₂ · nH₂O (compound I, X = ClO₄, n = 3; compound II, X = NO₃, n = 2; compound III, X = Cl, n = 0.5; compound IV, X = 1/2SO₄, n = 0) is isolated by the reactions of the copper(II) salts with quinolinaldehyde semicarbazone (HL). Regardless of the reactant ratio, only the compounds with a metal to ligand mole ratio of 1: 1 are formed, where the organic reactant is coordinated in the molecular form. The X-ray diffraction analyses of the [Cu(HL)(NO₃)(H₂O)](NO₃) · H₂O (II) and [Cu(HL)Cl₂] · 0.5H₂O(III) compounds show their substantially different organizations of the molecular structures depending on the specifics of the acido ligand. An ionic structure with one NO ₃ ^? anion incorporated into the inner coordination sphere of the metal as a bidentate chelate ligand is observed in compound II. Molecular tetragonal pyramidal complexes associated into a dimer due to the bridging function of one coordinated Cl^? anion are formed in structure III. The coordination polyhedron of the copper atom in structures II and III is an asymmetrically extended tetragonal bipyramid. The CuClCu angle equal to 90° and the distance between two planes in compound III equal to 2.978 Å determine the insignificant antiferromagnetic interaction in this compound (g = 2.1, J = ?2.5 cm^?1).     

Cobalt(II) complexes with pentadentate Schiff bases 2,6-diacetylpyridine hydrazones: Syntheses and structures

Seven new cobalt(II) complexes based on the Schiff bases, 2,6-diacetylpyridine bis(isonicotinoylhydrazone) (H₂L¹) and 2,6-diacetylpyridine bis(nicotinoylhydrazone) (H₂L²), are synthesized and studied by X-ray diffraction analysis: [Co(H₂L¹)(NCS)₂] · 2.25H₂O (I), [Co(H₂L²)(NCS)₂] · CH₃OH (II), [Co(H₂L²)(NCS)(H₂O)]NCS (III), [Co(H₄L¹)(NCS)₂](NO₃)₂ · 2H₂O (IV), [Co(H₄L¹)(NCS)₂][Co(NCS)₄] · 0.75H₂O (V), [Co(H₄L²)(NCS)₂][Co(NCS)₄] · 1.75H₂O (VI), and [Co(H₂L²)(NCS)(CH₃OH)]₂[Co(NCS)₄] · 2CH₃OH (VII) (CIF files CCDC 941186 (I), 1457906 (Ia), 1457905 (II), 941187 (III), 1457907 (IV), 1457908 (V), 1457909 (VI), and 941188 (VII)). The organic ligands in the complexes act as pentadentate neutral H₂L or doubly protonated (H₄L)²⁺ coordinated through the same set of donor atoms N₃O₂. In all compounds I–VII, the coordination polyhedron of the Co²⁺ ion in a complex with the Schiff bases has a shape of a pentagonal bipyramid. The hydrazones are arranged in the equatorial plane of the bipyramid. Its axial vertices are occupied by the nitrogen atoms of the NCS￣ anions in compounds I, II, and IV–VI and by the nitrogen atoms of NCS￣ and oxygen of the water molecule in compound III or methanol in compound VII. The NO ₃ ^- anions or [Co(NCS)₄]^2￣ complex anions obtained by the reactions are involved along with the NCS￣ anions in the formation of compounds IV–VII.     

Structure and photoluminescence of Zn(II) and Сd(II) complexes with chiral bis-pyridine containing fragments of natural (–)-α-pinene

Complexes ZnLCl₂ (I) and [CdLCl₂] _n (IV), where L is chiral bis-pyridine containing fragments of natural monoterpenoide (–)-α-pinene are synthesized. Single crystals of [ZnLCl₂]·CH₂Cl₂ (II), [ZnLCl₂]·i-PrOH (III), and IV compounds are grown. The crystal structures of II and III are composed of mononuclear ZnLCl₂ complex molecules and solvate CH₂Cl₂ and i-PrOH molecules; the coordination polyhedron of the zinc atom Cl₂N₂ is a distorted tetrahedron. According to the single crystal XRD data, complex IV is a 1D coordination polymer; the coordination core CdN₂Cl₄ is a distorted octahedron and Cl atoms are bridging ligands. In the structures of II, III, and IV the L molecule functions as a bidentate chelate ligand. In the solid phase, complexes I and IV exhibit photoluminescence in the visible range (λ_max 505 nm and 460 nm respectively). The band intensity in the photoluminescence spectra of I and IV complexes considerably exceeds the band intensity in the spectrum of free L.     

Copper(II) and cobalt(II) complexes with a chiral 5-pyrazolone derivative obtained from the terpene (+)-3-carene: Synthesis and properties

The complexes [CuLCl₂] (I), [CoLCl₂] (II), and CuLBr₂ (III) (where L is the derivative of optically active 5-pyrazolone prepared from the terpene (+)-3-carene) were obtained and characterized. According to X-ray diffraction data, crystal structures I and II (orthorhombic crystal system) are built from mononuclear acentric molecules. In the resulting complexes, the Cu²⁺ or Co²⁺ ion coordinates two N atoms of the chelating bidentate ligand L and two Cl atoms, thus making a distorted tetrahedron. Intermolecular contacts and the hydrogen bonds Cl(1)…H-O(1) give rise to columns parallel to axis y. For complexes I and III, μ_eff = 1.83 and 1.81 μB, respectively; these values correspond to the electronic configuration d ⁹ . For complex II, μ_eff = 4.42 μB, which suggests the tetrahedral structure of the coordination entity CoCl₂N₂. Complexes I and III were studied by EPR spectroscopy.     

Synthesis,crystal structures,and properties of copper(II) dicarboxylate complexes with [bis(2-pyridylcarbonyl)amido]

Four new complexes, [Cu₂(Bpca)₂(L¹)(H₂O)₂] · 3H₂O (I), [Cu₂(Bpca)₂(L²)(H₂O)₂] (II), [Cu₂(Bpca)₂(L³)] · 2H₂O (III), [Cu₂(Bpca)₂(L¹)(H₂O)] · 2H₂O (IV) (Bpca = bis(2-pyridylcarbonyl)amido, H₂L¹ = glutaric acid, H₂L² = adipic acid, H₂L³ = suberic acid, H₂L⁴ = azelaic acid) have been synthesized and characterized by single-crystal X-ray diffraction methods (CIF files CCDC nos. 1432836 (I), 1432835 (II), 817411 (III), and 817412 (IV)), elemental analyses, IR spectra. Structural analyses reveal that compounds I, II, and IV have similar structures [Cu(Bpca)]⁺ units bridged by dicarboxylate forming dinuclear units, whereas the dinuclear of compound III are edge-shared through two carboxylate oxygen atoms of different suberate anions. Hydrogen bonds are response for the supramolecular assembly of compounds I to IV. The temperature-dependent magnetic property of III was also investigated in the temperature range of 2 to 300 K, and the magnetic behaviour suggests weak antiferromagnetic coupling exchange.     

Synthesis and crystal structures of binuclear complexes of cobalt(II) and cadmium(II) diisobutyldithiophosphinates with hexamethylenetetramine

Heteroligand complexes [Co₂(HMTA)(iso-Bu₂PS₂)₄] (I) (μ_eff = 4.67 μB) and [Cd₂(HMTA)(iso-Bu₂PS₂)₄] (II) have been synthesized. Single crystals of compounds I and II have been obtained. The crystals are monoclinic: a = 32.622(2) Å, b = 9.4891(6) Å, c = 21.7570(13) Å, β = 125.774(1)^o, V = 5464.3(6) Å,³, Z = 4, ρ_calcd = 1.331 g/cm³ for I; a = 34.6092(7) Å, b = 9.5595(2) Å, c = 22.3473(5) Å, β = 127.144(1)^o, V = 5893.5(2) Å, Z = 4, ρ_calcd = 1.355 g/cm³ for II; space group for both complexes C2/c. Structures I and II are based on discrete binuclear molecules. The coordination polyhedra of the Co and Cd atoms are distorted tetragonal pyramids NS₄, with the bases formed by four S atoms of two bidentate chelating ligand iso-Bu₂PS ₂ ^? and the axial vertices occupied by N atoms of bidentate bridging HMTA ligand. The character of interaction of the molecules in structures I and II is considered.     

Pd(II) and Au(I) chloride complexes with tetrakis(butylthiomethyl)calix[4]arene: Synthesis and crystal structures

Two novel complexes, (AuCl)₄L³(I) and (PdCl₂)₂L³(II) (L³ is calix[4]arene-thioether), were synthesized and their structures were determined. In complex I, one thioether group of molecule L³ is coordinated to every Au atom. In complex II, the bidentate coordination of L³ to the Pd atoms is observed; two thioether groups are in the trans-positions in the Pd square surrounding. Both complexes have the layered crystal lattices. In the Au complex, the layers are more stable due to the short contacts Au-Au (3.19–3.23 Å).     

Mono- and heteroligand iron(II) complexes with tris(3,5-dimethylpyrazol-1-yl)methane

Coordination compounds of iron(II) thiocyanate with tris(3,5-dimethylpyrazol-1-yl)methane (HC(3,5-Me₂Pz)₃), [Fe(HC(3,5-Me₂Pz)₃)₂](NCS)₂] (I) and [Fe(HC(3,5-Me₂Pz)₃)(Рhz)(NCS)₂] · H₂O (II), where Рhz is phthalazine, are synthesized. The complexes are studied by X-ray diffraction analysis, diffuse reflectance and IR spectroscopy, and static magnetic susceptibility measurements. The single crystals are obtained, and the molecular and crystal structures of complex II and compounds [Fe(HC(3,5-Me₂Pz)₃)(3,5-Me₂Pz)(NCS)₂] · С₂H₅OH (III), where 3,5-Me₂Pz is 3,5-dimethylpyrazole, and [Fe(HC(3,5-Me₂Pz)₃)₂][Fe(HC(3,5-Me₂Pz)₃)(NCS)₃]₂ (IV) are determined (CIF files CCDC 1415452 (II), 1415453 (III), and 1415454 (IV)). The study of the temperature dependence μ_eff(Т) in a range of 2–300 K shows exchange interactions of the antiferromagnetic character between the iron(II) ions in complexes I and II.     

Cobalt(II) and nickel(II) cloride complexes with 4,5-(<Emphasis Type="Italic">n</Emphasis>-pyridylethylene)-dithio-1,3-dithiol-2-thiones (<Emphasis Type="Italic">n</Emphasis> = 2, 4)

The NiCl₂ and CoCl₂ complexes with 4,5-(2-pyridylethylene)-dithio-1,3-dithiol-2-thione (L¹) and 4,5-(4-pyridylethylene)-dithio-1,3-dithiol-2-thione (L²) were described. The L¹ ligand shows bidentate coordination through the pyridyl N atoms and the thiol S atoms in a tetrahedral [CoCl₂(L¹)] complex (I) and in an octahedral [NiCl₂(L¹)₂](MeCN)₂ complex (II). The L² ligand exhibits monodentate coordination through the pyridyl N atom in tetrahedral complexes [CoCl₂(L²)₂ (III) and [NiCl₂(L²)₂] (IV). Complexes I, III, IV in crystal state are octahedral due to extra coordination of the thione S atoms or the chloride bridges responsible for the polymeric structure. The structure of the complex II · CH₂Cl₂ was determined by X-ray diffraction analysis. The crystals are monoclinic, space group P2₁/c, a = 11.895(2) Å, b = 13.374(3) Å, c = 21.873(4) Å, β = 95.30(3)°, Z = 2. The Ni atom has quasi-tetrahedral surrounding due to two chloride ions and two L¹ ligands coordinated through the pyridyl N atoms and the thiol S atoms.     

Copper(II) Complexes with Chiral Ligands Containing Fragments of Monoterpenoids and Amino Acid Esters

Complexes [CuL¹Cl₂] (I), [CuL²Cl₂] · EtOH (II), and Cu₂L³Cl₄ (III) containing esters of the N-derivatives of optically active amino acids based on (+)-3-carene (L¹, L²) and (?)-α-pinene (L³) are synthesized. The crystal and molecular structures of compounds I and II are determined by X-ray diffraction analyses (CIF files CCDC nos. 1560071 (I), 1560072 (II)). The crystal structure of compound I consists of mononuclear complex molecules. In the structure of compound II, the unit cell contains two crystallographically independent molecules of mononuclear complex [CuL²Cl₂] and two EtOH molecules. Ligands L¹ and L² perform the tridentate-chelating function by the N atoms of the NH and NOH groups and by the O atom of the C=O group. In compounds I and II, the coordination polyhedra Cl₂N₂O of the Cu atoms are trigonal bipyramid. According to the data of IR and electronic spectroscopy, binuclear complex III has similar coordination polyhedra. The experimental values of μ_eff for compounds I, II, and III at 300 K are 1.93, 1.88, and 2.71 μB. For complex III, the μ_eff(T) dependence in a range of 2–300 K indicates a weak ferromagnetic exchange interaction.     

Complexes of Cu(II) and Co(II) nitrates with 3-Phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline

Complexes of Cu(II) and Co(II) nitrates with 3-phenyl-5,5-dimethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinoline (L⁰) of the composition [CuL ₂ ⁰ (NO₃)₂] (I) and [CoL ₂ ⁰ (NO₃)₂] · CH₃CN (II) are synthesized and their crystal structures are determined by X-ray diffraction. The L⁰ ligand is coordinated to the metal atoms through the N atom in position 2 of triazole fragment. The coordination polyhedron of the Cu(II) atom is a square with two additional axial vertices, while that of the Co(II) atom is a tetrahedron with two additional vertices. The NO ₃ ^? groups in the structures of I and II perform similar anisobidentate function. Complexes I and II are studied by IR and electronic spectroscopy.     

Synthesis and structure of new copper(II) coordination compounds with 8-quinoline aldehyde semicarbazones and thiosemicarbazones

Copper(II) salts were reacted with various quinoline aldehyde chalcogensemicarbazones to yield compounds formulated as Cu(HL)X₂ · nH₂O (I: HL = quinoline aldehyde thiosemicarbazone (HL¹), X = ClO₄, n = 2; II: HL = quinoline aldehyde 4-C₂H₅-thiosemicarbazone (HL^1a), X = NO₃, n = 0; III: HL = quinoline aldehyde semicarbazone (HL²), X = ClO₄, n = 3 and IV: HL = quinoline aldehyde 4-Ph-semicarbazone (HL^2a), X = NO₃, n = 1). Regardless of the reagent ratio, the products were compounds having the metal: ligand ratio of 1: 1, where the organic ligand was coordinated tridentate in a molecular form. Single-crystal X-ray diffraction showed that, depending on the chalcogen atom in the organic ligand (S or O), the substituent in the 4th position (at the terminal nitrogen atom), and the specifics of the acido ligand, complexes I–IV had appreciably differing molecular structure organizations. The structures of I and III are formed by a 1D charged coordination polymer, ClO ₄ ^? anions, and water molecules and may be described by the formula [Cu(HL)(H₂O)(ClO₄)] _n (ClO₄) _n · nH₂O. Copper(II) coordination polyhedra in I and II are (4 + 2) and (4 + 1 + 1) tetragonal bipyramids, respectively. In II and IV, the structures are monomeric and can be described as [Cu(HL^1a)(NO₃)₂] with the metal coordination polyhedron shaped as a (4 + 1) tetragonal pyramid in II and as [Cu(HL^2a)(H₂O)(NO₃)](NO₃) with the metal coordination polyhedron shaped as a (3 + 2) trigonal bipyramid in IV. The structure of II is built of molecular complexes, each comprising, apart from ligand HL^1a, two monodentate coordinated NO ₃ ^? groups. The oxygen atom of one anion together with the NNS donor atom set of ligand HL^1a form the base, and the oxygen atom of the other anion is in the apex of the coordination polyhedron. In IV, the structure is ionic and built of NO ₃ ^? anions and [Cu(HL^2a)(H₂O)(NO₃)]⁺ complex cations, where a cationic coordination polyhedron has a trigonal-bipyramidal configuration with organic ligand HL^2a positioned along the long edge. The bipyramidal base is made up by the oxygen atoms of the coordinated water molecule and monodentate nitrato group and the nitrogen atom N2 of the azomethyne group.     

Microwave-assisted synthesis,crystal structures,and in vitro antibacterial studies of zinc(II) and nickel(II) complexes with Schiff bases

The syntheses of a mononuclear zinc(II) complex [ZnCl(L¹)(Amp)] (I) and a mononuclear nickel(II) complex [Ni(L²)(HL²)](BF₄) · 0.5H₂O (II) (HL¹ = 4-methyl-2-[(4-methylpyridin-2-ylimino) methyl]phenol, HL² = 4-methyl-2-[(pyridin-2-ylmethylimino)methyl]phenol; Amp = 2-amino-4- methylpyridine) were prepared under microwave irradiation. The complexes were characterized by a combination of elemental analyses, and IR and electronic spectra. Their structures were further confirmed by single crystal X-ray crystallography (СIF files CCDC nos 1437737 (I), 1437738 (II)). The Zn atom in the monomeric complex I is in tetrahedral coordination. The Ni atoms in the dimeric complex II are in octahedral coordination. Crystals of the complexes are stabilized by hydrogen bonds. In order to evaluate the biological activity of the complexes, in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa was assayed. The complexes have strong activity against Bacillus subtilis.     

(18-Crown-6)(nitrato-<Emphasis Type="Italic">O,O</Emphasis>′)potassium and (18-crown-6)(nitrato-O,O′)potassium<Subscript>(0.91)</Subscript>silver<Subscript>(0.09)</Subscript>: Synthesis and crystal structures

Two complexes with similar compositions are synthesized: (18-crown-6)(nitrato-O,O′)potassium (I) and (18-crown-6)(nitrato-O,O′)potassium_(0.91)silver_(0.09) (II). Their isomorphic orthorhombic crystals (space group P2₁2₁2₁, Z = 4) are studied by X-ray diffraction analysis. Structure I (a = 8.553 Å, b = 11.967 Å, c = 17.871 Å) and structure II (a = 8.540 Å, b = 11.956 Å, c = 17.867 Å) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.044 (I) and 0.055 (II) for all 2385 (I) and 2379 (II) measured independent reflections. Complex molecules [K(NO₃)(18-crown-6)] in structure I and [K_0.91Ag_0.09(NO₃)(18-crown-6)] in compound II are of the host-guest type and rather similar in structure. Their 18-crown-6 and NO ₃ ^? ligands are disordered over two orientations. The K⁺ cation in complex I and the mixed cation (K_0.91Ag_0.09)⁺ in complex II reside in the cavity of the disordered 18-crown-6 ligand and is coordinated by its six O atoms and by two disordered O atoms of the NO ₃ ^? . ligand. The coordination polyhedron (CN = 8) of the K⁺ cation in complex I and that of (K_0.91Ag_0.09)⁺ cation in complex II is a distorted hexagonal pyramid with a base of six O atoms of the 18-crown-6 ligand and a split vertex at two O atoms of the NO ₃ ^? ligand.     

The Cu(II) complexes with bis(pyrazole-1-yl)methane and its derivatives: Synthesis,crystal structure,and magnetic properties

The procedures for the synthesis of the Cu(II) complexes with bis(pyrazole-1-yl)methane (L¹), bis(3,5-dimethyl-4-bromopyrazole-1-yl)methane (L²), and bis(3,5-dimethyl-4-iodopyrazole-1-yl)methane (L³) of the composition Cu₂(L¹)₂Br₄ (I), Cu₂(L²)₂Cl₄ (II), Cu(L³)(NO₃)₂ (III), and Cu(L³)(H₂O)(NO₃)₂ · 2H₂O (IV) were developed. The organic ligands in the above complexes are coordinated to Cu(II) in a bidentate cyclic type through the N(2), N(2′) atoms of the pyrazole rings. The molecular and crystal structures of L², L³, II, III, and IV were determined by X-ray diffraction. The study of the μ_eff(T) function in a temperature interval 2–300 K showed that compound I, which exhibited ferromagnetic exchange interactions in the chains, undergoes transition to antiferromagnetic state with weak ferromagnetism. The exchange antiferromagnetic interactions predominate in compound II.