Synthesis and Structure of the Copper(II) Nitrate Complex with 1-(3-Methyl-1-phenylpyrazol-5-onylidene-4)-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline

The complex [CuL(NO₃)₂] ? CH₃CN(I), where L is 1-(3-methyl-1-phenylpyrazol-5-onylidene-4)-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, is synthesized and studied by X-ray diffraction and IR and electronic absorption spectroscopies. Complex I is prepared by the reaction of copper(II) nitrate crystal hydrate with L in acetonitrile. The coordination polyhedron of the Cu atom in I is a distorted (4 + 1) five-vertex polyhedron, and ligand L in the structure acts as N,O-bidentate bridge. The nitrate groups in I perform different structural functions: monodentate-terminal and anisobidentate. Structure I is composed of polymeric chains -L-Cu(NO₃)₂-L- and solvate acetonitrile molecules arranged between the chains.     

Cobalt(II) and copper(II) complexes with chiral pyrazolylquinoline,a derivative of terpenoid (+)-3-carene. Catalytic activity in ethylene polymerization reaction

Coordination compounds [CoLCl₂] (I), [CuLCl(NO₃)] (II), CuL(NO₃)₂ (III), and CuLCl₂ (IV) (where L is a chiral pyrazolylquinoline—a derivative of terpenoid (+)-3-carene) were synthesized. X-ray diffraction data showed that crystal structures I and II are built of mononuclear acentric molecules. In the molecule of complex I, the Co₂₊ ion coordinates two N atoms of bidentate cycle-forming ligand L and two Cl atoms. The coordination polyhedron of Cl₂N₂ is a distorted tetrahedron. For complex I, μ_eff = 4.50 μ_B, which corresponds to a high-spin configuration d ⁷. In the molecules of II(1), II(2) (which are diastereoisomers of complex II), each Cu²⁺ ion coordinates two N atoms of bidentate cycle-forming ligand L, the Cl atom, and two O atoms of bidentate cyclic NO ₃ ^? ion. The ClN₂O₂ coordination polyhedra are tetragonal pyramids with different degrees of distortion. The structure of complex II consists of supramolecular clusters, i.e., isolated chains incorporating the molecules of II(1) and II(2). The values of μ_eff for II–IV correspond to the d ⁹ configuration. The results of EPR and IR study suggest that complex III contains the O₄N₂ polyhedron, whereas complex IV contains the Cl₂N₂ polyhedron. Complexes I and IV were found to show a high catalytic activity in ethylene polymerization reaction.     

Synthesis and structure of <Emphasis Type="Italic">cis</Emphasis>-dichloro(triphenylstibine)(dimethylsulfoxide)platinum(II)

The platinum molecular complex cis-Cl₂(Ph₃Sb)(Me₂S=O)Pt (I) was synthesized by the reaction of tetraphenylstibonium chloride with potassium tetrachloroplatinate in dimethyl sulfoxide. The crystal structure of square-planar complex I was determined by X-ray crystallography. The complex contains, in addition to chlorine atoms, triphenylstibine and DMSO molecules coordinated to the central atom. The bond lengths Pt-Cl, Pt-S, and Pt-Sb are 2.308(1), 2.350(1), 2.195(1), and 2.5118(4) Å, respectively. The compound is the first example of mixed-ligand platinum(II) complex in which the coordination sphere of the central atom contains, along with dimethyl sulfoxide ligand, a tertiary stibine ligand.     

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.     

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.     

Crystal structure of 4,4-bipyridine-containing complexes of copper(II) nitrate with 1-[(2-Hydroxyethylimino)methyl]naphthalen-2-ol and 2-[(2-hydroxyethylimino)methyl]phenol

The crystal structures of (μ-4,4-bipyridine)-di(nitrato-1-[(2-hydroxyethylimino)methyl]naphthalen-2-olocopper (I) and catena-di(μ-4,4’-bipyridine)di(μ-4,4’-bipyridine)-di(nitrato-2-[2-(hydroxyethylimino) methyl]phenolocopper)diaquacopper(II) nitrate (II) were determined. In the crystal of I, each of the two copper atoms coordinates a singly deprotonated tridentate azomethine molecule, a nitrate ion, and bipyridine, which functions as a bridge between the central atoms. The copper coordination polyhedron is a slightly distorted tetragonal pyramid with the base formed by the imine and bipyridine nitrogen atoms and the phenol and alcohol oxygen atoms. The axial site in the pyramid is occupied by the oxygen atom of the monodentate nitrate groups. In the trinuclear structure II with C₂ crystal chemical symmetry, the terminal coordination unit is composed through copper coordination of monodeprotonated 2-[2-(hydroxyethylimino)methyl]phenol, bipyridine, and the nitrate anion. In the crystal, the trinuclear molecules form infinite ribbons along the z axis in which the pyridine molecules perform the bridging function. The central copper atom has an octahedral configuration formed by the nitrogen atoms of four 4,4’-bipyridine molecules and oxygen of two water molecules.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol with urease inhibitory activity

A new mononuclear cobalt(III) complex, [CoL₂(N₃)]₂ · CH₃OH (I), and a new mononuclear zinc(II) complex, [ZnLCl(CH₃OH)] (II) (HL = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol), were prepared and structurally characterized by elemental analyses, infrared spectroscopy, and single- crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 18.742(2) Å, b = 15.197(2) Å, c = 25.646(2) Å, β = 125.996(3)°, V = 5909.8(11) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.257(1) Å, b = 24.707(2) Å, c = 9.637(1) Å, β = 101.557(2)°, V = 1692.9(3) ų, Z = 4. The Co atom in I is in an octahedral coordination, and the Zn atom in II is in a trigonal-bipyramidal coordination. The urease inhibitory test shows that complex I has strong urease inhibitory activity, while complex II has no activity.     

Synthesis,structure, and blue photoluminescence of the coordination chain polymer [Cd<Subscript>2</Subscript>(L)Cl<Subscript>4</Subscript>]<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> (L = 2-(3,5-dimethylpyrazol-1-yl)-4-methylquinoline)

The complex of CdCl₂ with 2-(3,5-dimethylpyrazol-1-yl)-4-methylquinoline (L), Cd₂(L)Cl₄ (I), is synthesized. According to the X-ray diffraction data, the structure of coordination polymer I is formed by chains in which two crystallographically independent Cd atoms linked by the bridging Cl atoms have different coordination numbers (5 and 6) and different environments. Five Cl atoms form the coordination polyhedron of the Cd(2) atom: a square pyramid (Cd-Cl 2.554(3)–2.689(3) Å) completed to a bipyramid by the CI atom at a substantially longer distance of 2.865(4) Å. Two Cl atoms and the N atom of quinoline fragment L are arranged in the equatorial plane of the coordination polyhedron of the Cd(1) atom, which is a distorted trigonal bipyramid. The axial vertices are occupied by the N atom of the pyrazole cycle of L and the Cl atom. Five-membered metallocycles CdCN₃ are formed upon the coordination of bidentate chelating ligands L. The planes of L of two adjacent chains are parallel (the distances between them are ～3.5 Å), which suggests the π-π interaction between the planes. The luminescence excitation spectrum of compound I has a broad band with λ_max = 350 nm. The spectrum of bright blue photoluminescence of compound I (300 K, λ_exc = 340 nm) contains an intense band with λ_max = 420 nm.     

Crystal and Molecular Structure of Bis(1-Vinylimidazole)diacetatozinc

The crystal and molecular structure of bis(1-vinylimidazole)diacetatozinc (C₁₄H₁₈N₄O₄Zn), a highly effective antidote and antihypoxic drug, was determined [R₁ 0.0335 for 8902 unique reflections with I > 2σ(I) and wR₂ 0.0931 for all 10 752 unique reflections]. The triclinic unit cell contains two independent molecules of the complex, A and B. These molecules have short contacts O?H-C. The zinc atoms in molecules A and B have distorted tetrahedral coordination with the coordination sites occupied by the imidazole nitrogen atoms and acetate oxygen atoms. The lengths of the Zn-N bonds (2.019–2.050 Å) and Zn-O bonds with three acetate groups (1.956–1.958 Å) are typical for zinc complexes, whereas the Zn-O³ bond with one of the acetate groups in molecule A is somewhat longer, 2.009(1) Å; also, there is an additional contact of the zinc atom with the carbonyl oxygen atom of this group (Zn-O⁴ 2.498 Å).     

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).     

Experimental and computational studies of [N'-(2-hydroxy-3-methoxybenzylidene)-4-methylbenzenesulfonohydrazide]nickel(II)

Mononuclear Ni(II) complex (C₃₀H₃₀NiN₄O₈S₂) (I) has been obtained with 1: 2 metal/ligand ratio and characterized by single crystal X-ray diffraction (CIF file CCDC no. 1040830), IR, UV-Vis spectroscopic techniques and DFT. X-ray results show that complex I crystallizes in the monoclinic system, space group P2₁/n with four molecules in the unit cell. In structure I, the coordination around Ni atom is distorted square planar. In addition to the crystal structure, the molecular geometry, vibrational frequencies, molecular electrostatic potential, and frontier molecular orbital analysis of compound I in the ground state have been calculated using the B3LYP/6-311G and B3LYP/3-21G methods. The computed vibrational frequencies are used to determine the types of molecular motions associated with each of the observed experimental bands.     

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.     

Supramolecular Heteroleptic Copper(II) Carboxylates: Synthesis,Spectral Characterization,Crystal Structures,and Enzyme Inhibition Assay

Two new complexes of substituted phenyl acetic acids with CuSO₄ · 5H₂O and 2,2′-bipyridine (Bipy) with formula [CuL(Bipy)₂]L · nH₂O, where L = 2-ClC₆H₄CH₂COO^– (I), 2-CH₃-3-NO₂C₆H₃CH₂COO^– (II) and n = 3 (I); 4 (II), have been synthesized. These complexes have been characterized by elemental analysis, FT-IR and X-ray crystal diffraction (CIF file CCDC nos. 1487707 (I), 1487708 (II)). Both complexes are mononuclear and crystallize in the triclinic space group P1?. In both complexes two molecules of Bipy bind equatorially with metal atom and one molecule of substituted phenyl acetic acid binds at axial position giving rise to a distorted five coordinated geometry around copper atom, while the second oxygen atom of carboxylate ligand appears to occupy the sixth position resulting in highly distorted six coordination environments around metal center in both complexes. However, another molecule of substituted phenyl acetic acid along with water molecules lies as co-crystal within the crystal lattice. Two bipyridine molecules in both complexes are lying in different planes and are oriented at dihedral angle of 63.89(8)° and 74.99(11)° in complexes I and II, respectively. Extensive hydrogen bonding because of water molecules present in crystal lattice plays a vital role in the formation of the 3D structure. Additionally, other weak interactions such as π–π interactions markedly influence the supramolecular structure. An investigation of DNA binding ability of both complexes using UV-visible spectroscopy and anti-diabetic capacity is also presented. Results revealed that synthesized complexes bind with SSDNA through intercalation as well as groove binding mode with K_b values of 2.45 × 10⁴ and 7.72 × 10³ M^–1 for complex I and II, respectively. Complex II strongly inhibits in-vitro α-glucosidase with IC₅₀ value of 30.4 μM, while complex I moderately inhibits in-vitro α-amylase with IC₅₀ value of 69.9 μM. Acarbose was employed as standard in both assays.     

Binuclear Cyclic Silver(I) Complex with the Anion of 4-[(2-Diphenylphosphanylphenyl)methyleneamino]benzoic Acid: Synthesis,Structure, and Optical Properties

4-[(2-Diphenylphosphanylphenyl)methyleneamino]benzoic acid (HL) is obtained by the condensation of o-diphenylphosphinobenzaldehyde and p-aminobenzoic acid. The reaction of AgNO₃ and HL affords complex [Ag₂L₂] · H₂O (I). The structure of complex I is determined by X-ray structure analysis (CIF file CCDC 1575064), and its reflectance and luminescence spectra are studied. Binuclear complex I is a cyclic molecule in which each of two silver(I) atoms coordinates one phosphorus atom and one oxygen atom of two bridging anions L. Compound I is characterized by emission in a range of 430–740 nm at λ_exc = 340 and 395 nm.     

Synthesis and crystal structure of (1<Emphasis Type="Italic">H</Emphasis>-Benzo[<Emphasis Type="Italic">d</Emphasis>]imidazol-2-yl)(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)methanone (L). complex formation of copper(II) and cobalt(II) chlorides with L

(1H-Benzo[d]imidazol-2-yl)(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)methanone (L) and its complexes with copper and cobalt chlorides [CuLCl₂] (I) and [CoLCl₂] (II) are synthesized and studied by IR spectroscopy. The structure of molecule L is determined by X-ray diffraction analysis. Molecule L crystallizes as a cis-trans isomer. The dihydroisoquinoline (A) and benzimidazole (B) fragments lie in the mutually perpendicular planes. The N-C bond lengths of fragment A (double bond N(1)-C(1) 1.278(3) Å, ordinary bond N(1)-C(9) 1.490(3) Å) differ noticeably. The N-C bond lengths in fragment B range from 1.327(4) to 1.389(4) Å. The C=O bond is 1.218(3) Å According to the data of IR spectroscopy and X-ray diffraction analysis, complexes I and II are assumed to have different structures with different coordination modes to the metal atom of molecule L: through the imine atoms N(1) and N(2) of fragments A and B in I and through the N(1) atom of the dihydroisoquinoline fragment and the O atom of the carbonyl group in II.     

Copper(I) complexes with phenylphosphonous acid diamide

Copper(I) halide complexes with phenylphosphonous diamide ligand (L), C₅₆H₁₀₀Br₄Cu₄N₈P₄ (II) and C₅₆H₁₀₀Cu₄I₄N₈P₄ (III), were synthesized and studied by X-ray diffraction to determine their molecular and crystal structures (CIF files CCDC nos. 1426622 (II), 1426623 (III)). The prepared coordination compounds are cubane-like tetramers like L₄Cu₄X₄. During the reaction, copper(I) is coordinated to the phosphorus atom of ligand L. The stability of the complexes depends considerably on the halogen atom. The iodide complexes are most stable during storage.     

Synthesis,crystal structures,and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

An end-to-end azido-bridged dinuclear copper(II) complex [Cu₂L₂(μ_1,3-N₃)](NO₃) (I) and a mononuclear zinc(II) complex [ZnCl₂(HL)] ? CH₃OH (II), where L is 2-brom-4-chloro-6-[(2-morpholin- 4-ylethylimino)methyl]phenolate, have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination (CIF files CCDC nos. 1415217 (I), 1415218 for (II)). The crystal of I is monoclinic: space group C2/c, a = 28.684(2), b = 7.1787(5), c = 18.292(1) Å, β = 117.887(3)°, V = 3329.1(4) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 10.8207(9), b = 12.3398(7), c = 14.9477(7) Å, β = 93.473(3)°, V = 1992.2(2) ų, Z = 4. The Schiff base ligand in I coordinates to the Cu atom through the phenolate O, imine N, and morpholine N atoms, while the Schiff base ligand in II coordinates to the Zn atom through the phenolate O and imine N atoms, with the morpholine N atom protonated. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.     

Crystal structures of the polymer copper(II) complexes with acylhydrazones of bromosalicylaldehyde derivatives

Polymer copper(II) complexes with 5-bromosalicylaldehyde heptanoylhydrazone (I) and 3,5-dibromosalicylaldehyde acetylhydrazone (II) are synthesized and structurally characterized. In complex I, the formation of the polymer is due to the coordination of the hydrazide nitrogen atom to the copper(II) ion of the adjacent fragment. In complex II, polymer formation is due to the binding of the monomer fragments by dipyridyl linkers (CIF files CCDC 947908 (I) and 947909 (II)).     

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.