E. G. Boguslavskii

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, μeff = 4.50 μB, which corresponds to a high-spin configuration d7. 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 NO3− 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 μeff for II–IV correspond to the d9 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.

Co(II), Ni(II) and Cu(II) Complexes with 1-(4-Hydroxyphenyl)-1H-1,2,4-Triazole

New complexes of Co(II), Ni(II), and Cu(II) with 1-(4-hydroxyphenyl)-1H-1,2,4-triazole (L) of the composition ML2(H2O)2(NO3)2 · nH2O (M = Co(II), n = 3; M = Ni(II), n = 0; M = Cu(II), n = 0) were synthesized and studied by photoelectron and IR spectroscopy, magnetochemistry, thermogravimetry, and X-ray powder diffraction analysis. The type of μeff(T) relationship suggests that paramagnetic centers in the Co(II) chloride and Cu(II) nitrate and bromide complexes are involved in antiferromagnetic exchange interactions. The exchange energy values were estimated by the molecular field method.

Synthesis, Crystal and Molecular Structures, and Properties of Optically Active Copper(II) Complexes with 3-N,N-Dimethylaminocaran-4-one-oxime

Copper(II) complexes with 3-N,N-dimethylaminocaran-4-one-oxime (HL) were synthesized and characterized by X-ray diffraction analysis, photoelectronic, IR, and EPR spectroscopy, magnetic susceptibility, and thermal analysis methods, and their optical activities were studied. The [Cu2(HL)2Cl4] complex is a dimer with weak exchange interactions between unpaired electrons of the Cu(II) ions. The [Cu3L3(OH)Cl]Cl · 8H2O structure is composed of triangular trinuclear complex cations, outer-sphere Cl–anions, and water molecules. The exchange parameter Jfor the trinuclear exchange cluster is –190 cm–1. The title complexes are optically active in the visible range of the spectrum.

Cu(II) Complexes with Optically Active α-Alkylamino Oximes of Caryophyllene Type: Synthesis, Structure, and Properties

Paramagnetic complexes Cu(HL1)Cl2 (I), Cu(HL2)Cl2 · 2H2O (II), and Cu(HL1)Br2 (III) are synthesized by the reaction of copper(II) halides with the optically active α-alkylamino oximes HL1 and HL2 of caryophyllene type. Crystal and molecular structures of complex I are determined. The crystals are orthorhombic: a = 9.038(2) Å, b = 11.990(2) Å, c = 11.990(2) Å, V = 2004.8(7) Å3, space group P212121, Z = 4, ρ(calcd) = 1.812 g/cm3, R1 = 0.0632. In a mononuclear complex I, the coordination polyhedron of CuCl2N2 is a distorted square. The structures of complexes II and III are suggested on the basis of EPR, IR and Raman spectroscopy data.

Binuclear Copper(II) Complexes with (1R*,4S*)-1-N-Morpholino-n-menth-8-en-2-one E-oxime: Synthesis, Structure, and Magnetic Properties

Copper(II) complexes with (1R*,4S*)-1-N-morpholino-n-menth-8-en-4-one (HL), namely, [Cu2(HL)2Cl4] (I) and [Cu2(HL)LCl3] · CH3CN (II), were synthesized and characterized by X-ray diffraction analysis, magnetic susceptibility, and EPR methods. The complexes have binuclear structures. In compound I, the coordination polyhedron of CuCl3N2 is a square pyramid in planar Cu2Cl2 metal cycle; the exchange couplings of unpaired electrons of Cu(II) ions are weak. Complex II incorporates polyhedra of CuCl2N2 (flattened tetrahedron) and of CuCl2N2O (trigonal bipyramid). The Cu2ClNO metal cycle is nonplanar with antiferromagnetic exchange coupling and exchange parameter –2J = 182 cm–1. The EPR spectrum of compound I are analyzed.

Synthesis of solvates of the copper(II) complex with chiral caryophyllane-type morpholino oxime (HL). Structure of Cu(HL)Cl2 · CHCl3

Paramagnetic Cu(HL)Cl2 · 0.25CHCl3 (I) and Cu(HL)C12 · 0.25CH2C12 (II), where HL is the optically active morpholino oxime obtained from the terpenoid caryophyllene, were synthesized. The crystals of Cu(HL)Cl2 · CHCl3 (III) were isolated. According to X-ray diffraction data, the crystals of III are composed of acentric mononuclear complex molecules Cu(HL)Cl2 and solvate molecules CHCl3. In the complex molecules, the Cu ion coordinates two N atoms of the bidentate chelating ligand HL and two C1 atoms at the vertices of a distorted tetrahedron. The translationally identical molecules of the complex combined by H-bonds form chains along the axis x.

Copper(II) complexes with bis(4-iodo-3,5-dimethylpyrazol-1-yl)methane: Synthesis, spectroscopic study, and crystal structure

New complexes of copper(II) nitrate, chloride, tetrafluoroborate, perchlorate, and perrhenate with bis(4-iodo-3,5-dimethylpyrazol-1-yl)methane (L) were obtained. The molecular and crystal structures of [CuL(H2O)(NO3)2] · (CH3)2CO, [CuL2(H2O)][CuL2Cl][CuCl4], [CuL2](BF4)2 · (CH3)2CO, and [CuL2(H2O)](ClO4)2 · (CH3)2CO were determined by X-ray diffraction analysis. In all the complexes, L was found to serve as a chelating bidentate ligand through the N2 and N2′ atoms of its pyrazole rings to form a six-membered chelate ring.

Iron(II) clathrochelate with an annelated 4,5-dimercapto-[1,3]dithiol-2-thione moiety: Synthesis, structure, and redox reactions

Nucleophilic substitution of chlorine atoms in iron(II) dichloroclathrochelate induced by 4,5-dimercapto-[1,3]dithiol-2-thione dianion gave rise to a cage complex with an annelated sulfur-containing heterocyclic moiety. The composition and structure of this complex were determined by X-ray crystallography and multinuclear NMR spectroscopy in a crystal and in solution, respectively; cyclic voltammetry (CVA) and EPR were used to study the redox reactions of the complex in solution to yield a ligand-centered radical-anionic product.

Synthesis and Properties of Cu(II) and Pd(II) Complexes with Chiral Bis-α-sulfanyl Oxymes, the Derivatives of Natural Monoterpene, α-Pinene

Coordination compounds Cu2(H2L1)Cl4 (I), Pd2(H2L1)Cl4 (II), Cu2(H2L2)Cl4 (III), and Pd2(H2L2) Cl4 (IV) with chiral bis-α-sulfanyloximes, the derivatives of the monoterpenoid (−)-α-pinene, were obtained. The complexes I and III are paramagnetic (μeff = 2.45 and 2.67 μB, respectively), II and IV are diamagnetic. According to IR spectroscopy, in the compounds I–IV the nearest environment of Cu and Pd atoms includes N, S, and Cl atoms. The values of μeff and parameters of ESR spectra of the solid phase and solutions of I and III show a binuclear structure of the Cu(II) complexes. Parameters of the 1H and 13C NMR spectra of compounds II and IV indicate the formation of binuclear Pd(II) complexes of C2 symmetry and the closure of fivemembered chelate rings PdNSC2. The PdCl2 fragments are in transoid position. H2L1 and H2L2 are tetradentate bridging chelating ligands.

Synthesis and properties of the Cu(II) complexes with chiral bis{(E)-[(1S,4R)-Δ7,8-1-amino-2-para-menthalidene]aminohydroxy}methane (L — a derivative of natural terpenoid (R)-(+)-limonene). Crystal structure of the [Cu(L)(μ-Cl)CuCl3] · iso-PrOH solvate

The Cu2LCl4 complex (I) with chiral bis{(E)-[(1S,4R)-Δ7,8-1-amino-2-para-menthalidene]aminohydroxy} methane (L — a derivative of natural monoterpenoid (R)-(+)-limonene) is synthesized. The crystal structure of the solvate of complex I[Cu(L)(μ-Cl)CuCl3] · iso-PrOH (II) is determined by X-ray diffraction analysis. Structure II is based on molecules of the [Cu(L)(μ-Cl)CuCl3] binuclear complexes in which L is the tetradentate cycleforming ligand. One Cl atom manifests the bridging function. The CuN4 Cl coordination unit is a square pyramid, and CuCl4 is a distorted tetrahedron. The iso-PrOH molecules are localized in cavities between the layers of structure II. The μeff value for complex I is 2.56 μB and indicates the absence of an appreciable interaction between the Cu2+ ions in the Cu(II)-Cl-Cu(II) exchange cluster. The compound CuLCl2· H2O (III) is synthesized. The μeff value for compound III is 1.6 μB. Complexes I and III are studied by EPR and IR spectroscopy.