Synthesis and crystal structure of complexes of manganese(II), cobalt(II), and nickel(II) isothiocyanates with ?-caprolactam

The possibility of ?-caprolactam (CPL) to coordinate to manganese(II), cobalt(II), and nickel(II) rhodanides has been investigated. New complexes trans-[M(CPL)₄(NCS)₂], where M = Mn (I), Co (II), and Ni (III), have been synthesized. The complexes have been studied by chemical analysis and IR spectroscopy. According to X-ray diffraction, complexes are isostructural to each other and crystallize in monoclinic space group P2₁/c, Z = 2. For I: a = 6.9457(2) ?, b = 17.7751(6) 0A, c = 12.8999(4) 0A, ?? = 104.2670(10)°, V = 1543.51(8) ?³, ??_calc = 1.342 g/cm³, R ₁ = 0.0426. For II: a = 6.8925(2) ?, b = 17.8189(8) ?, c = 12.7278(6) ?, ?? = 104.421(2)°, V = 1513.93(11) ?³, ??_calc = 1.377 g/cm³, R ₁ = 0.0280. For III: a = 6.7804(2) ?, b = 18.4631(4) ?, c = 12.4841(3) ?, ?? = 105.2950(10)°, V = 1507.49(7) ?³, ??_calc = 1.382 g/cm³, R ₁ = 0.0273. Structures I?CIII are molecular; the metal atom in each of them coordinates four CPL molecules and two NCS groups via oxygen and nitrogen atoms, respectively.     

Rhenium(IV)–copper(II) heterobimetallic complexes: Synthesis,crystal structure and magnetic properties

Two Re(IV)–Cu(II) heterometallic complexes {(CuL_α)[ReCl₄(ox)]}_n (where L_α = N-meso-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 1, and (CuL_β)[ReCl₄(ox)] (L_β = N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 2, were synthesized. The [CuL²⁺] macrocyclic cation is coordinated from above and below by [ReCl₄(ox)]²⁻ units through the chloro-ligands and creates a chloro-bridged heterometallic Re^IV–Cu^II one-dimensional zig-zag chain. Compound 2 can be viewed as a heterobimetallic dinuclear unit, in which the Re(IV)-Cu(II) centers are linked by an oxalato bridge. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8–300 K. Compound 1 behaves like a ferrimagnetic {Re(IV)–Cu(II)} bimetallic, one-dimensional chain with intrachain antiferromagnetic coupling. Compound 2 shows a weak antiferromagnetic interaction within the [Re(IV)–Cu(II)] unit along with a strong single-ion anisotropy, D(Re) = −63 cm⁻¹.     

Molecular and crystal structure of iron(III) and nickel(II) complexes with 1′-phthalazinylhydrazones of heterocyclic carbonyl compounds

Journal of Structural Chemistry - The structures of iron(III) and nickel(II) complexes with the composition [FeL2]Cl·H2O (1) and [Ni(HL′2)]·DMSO·0.5H2O (2), where L and...     

Synthesis, crystal structure and forming mechanism of two novel copper (II) α-methacrylate complexes with benzimidazole

Two copper (II) α-Methacrylate complexes with benzimidazole, Cu[CH₂ = C(CH₃)-COO]₂ (C₃H₆N₂)₂(1) and Cu₂[CH₂ = C(CH₁)-COO]₂(C₃H₆N₂)₂(2), have been prepared and characterized by elemental analyses, IR and electronic reflectance spectroscopies. ’The single crystal X-ray diffraction study of the two complexes shows that complex 1 has a square planar configuration, while complex 2 has a binuclear cage structure. The crystal structural analyses show that both complexes 1 and 2 are monoclinic. with space group p2₁/c,a = 0.924 16(8) nm,b = 1.233 02(13) nm,c = 0.989 1(3) nm,β = 91.912 (13),D _c = 1.386 g/cm³,Z=2,R = 0.033 9 for the former; anda = 0.905 7(2) nm,b = 2.252 1(5) nm,c = 1.623 5(4) nm,β = 90.11 (2),D _c = 1.411 g/cm³,Z = 4,R = 0.056 8, Cu-Cu = 0.266 21 nm for tin latter. Different structural types of complexes 1 and 2 were produced simultaneously in the reaction of copper (II) α-methacrylate with benzimidazole in methanol solution. ’The forming mechanism of the complexes has been summanzed. Project supported by the national natural Science Foundation of China (Grant No. 29831010) and the Foundation of the State Key Laboratory of Coordination Chemistry of Nanjing university.     

Syntheses,crystal structures and magnetic properties of two cyano-bridged copper(I)–copper(II) mixed-valence complexes

Two cyano-bridged copper(II)–copper(I) mixed-valence assemblies, Cu(EAM)₂[Cu(CN)₂]₂ 1 (EAM?=?ethanolamine) and Cu(DETA)[Cu(CN)₂]₂·0.5H₂O 2 (DETA?=?diethylenetriamine), have been prepared and structurally and magnetically characterized. IR spectra indicate the presence of bridging cyano groups in both 1 and 2, confirmed by structure analyses; Cu(I)–CN–Cu(II), Cu(I)–CN–Cu(I) and Cu(I)–Cu(I) metal bond linkages are evident. In the lattice, a 3D network is formed by two [Cu(CN)₂]?^? units and one [Cu(EAM)₂]²⁺unit for 1. Variable temperature magnetic susceptibilities, measured in the 5–300?K range, indicate weak antiferromagnetic exchange interactions in complex 1.     

Synthesis,electrochemical properties and electro-oxidative polymerization of copper(II) and nickel(II) complexes with N′-benzoylthiourea ligands containing pyrrole groups

The synthesis of four N-benzoylthioureas containing pyrrole groups are described. The electrochemical behaviour of their copper(II) and nickel(II) complexes has been investigated in aprotic solvents by coulometry and by cyclic voltammetry which indicates that the electrochemical oxidation of copper complexes leads to the formation of Cu^II-benzylureate complexes. The oxidative polymerization of nickel complexes on platinum and a glassy carbon electrode, has been carried out in MeCN.The redox properties of the polymeric films formed have been examined by cyclic voltammetry. The films are catalytically active in the electroreduction of oxygen.     

Synthesis and crystal structure of lanthanum(III) Iodomercurate(II) complexes with ɛ-Caprolactam

The X-ray diffraction study of the crystalline products of the reaction between potassium tetraiodomercurate(II), ?-caprolactam, and lanthanum(III) nitrate at a ratio of 3: 16: 2 in an aqueous solution has shown the presence of the following three new crystalline compounds: [LaCpl₈]₂[HgI₄]₃ (I), [LaCpl₈][HgI₄]I₃ (II), and [LaCpl₇(H₂O)]₂[HgI₄]₂[Hg₂I₆] (III), where Cpl is ?-caprolactam ?-C₆H₁₁NO. Compounds I and II crystallize in tetragonal crystal system, space groups P4₂/n and $I\bar 4$ , respectively. For compound I, a = 18.59320(10) Å, c = 19.5782(3) Å, V = 6738.32(12) ų, Z = 2, and ρ_calc = 2.067 g/cm³. For compound II, a = 13.2245(10) Å, c = 20.0310(3) Å, V = 3503.17(6) ų, Z = 2, ρ_calc = 2.022 g/cm³. The crystals of compound III are monoclinic (space group P _{2 1}/n, a = 20.1202(6) Å, b = 14.0569(4) Å, c = 46.3228(12) Å, β = 93.4770(10)°, V = 13077.3(6) ų, Z = 4, ρ_calc = 2.274 g/cm³). [La(Cpl)₈]₂[Hg₂I₆]₃ (IV), a new double ionic complex salt, has also been synthesized and studied by X-ray diffraction. The crystals of compound IV are triclinic (space group $P\bar 1$ , a = 12.5021(3) Å, b = 14.6436(3) Å, c = 21.4695(4) Å, α = 84.2300(10)°, β = 87.2230(10)°, γ = 74.9970(10)°, V = 3776.30(14) ų, Z = 1, ρ_calc = 2.452 g/cm³). All complexes have a dicrete ionic structure, and the nearest surrounding of a La atom is distorted square-prismatic or trigonal-dodecahedral. The crystal packing of cations is distorted face-centered cubic (I and II) or body-centered cubic (III and IV) with anions located in its cavities.     

Synthesis and properties of double copper(I)–nickel(II) sulfite

Pourbaix diagrams of Cu–H₂SO4–H₂O and Ni–H₂SO₄–H₂O systems have been refined, and stability regions of the sulfite phases have been determined. State diagrams of double copper(I)–copper(II) and copper(I)–nickel(II) sulfites have been constructed. Double copper(I)–nickel(II) sulfite has been isolated from aqueous solutions saturated with sulfur dioxide. The solutions at different ratios of the metals have been studied by spectrophotometry; the isolated double sulfite has been studied by X-ray diffraction, IR spectroscopy, dispersion analysis, and thermal analysis. Fundamentals of thermodynamic prognostication of the Cu₂SO₃·MSO₃ double sulfites synthesis have been elaborated.     

The structure and EPR spectra of binuclear copper(II) complexes with acyldihydrazones of β-diketones

The synthesis and structure of binuclear copper(II) complexes with acyldihydrazones of some β-diketones are described. The molecular structure of the copper(II) complex [Cu₂L·4Py] with trifluoroacetylacetone succinyldihydrazone (H₄L) was determined by the single-crystal X-ray analysis. Central atoms are bridged by a chain of seven σ-bonds with a Cu...Cu distance of 8.750 Å. EPR spectra of copper(II) complexes with acyldihydrazones of trifluoroacetylacetone and lower dicarboxylic acids containing from one to four methylene groups in the aliphatic spacer show the seven-line HFS due to spin-spin coupling of unpaired electrons with the two equivalent copper nuclei (g = 2.110, a = (38.5–40.5)⊙10^?4 cm^?1). By extending polymethylene spacer, as well as by modifying starting β-diketone, an exchange interaction between paramagnetic centers is suppressed.     

Volatile complexes of Pd(II) with methoxy-β-iminoketones: Synthesis,properties, and crystal and molecular structure

This paper describes a procedure for the synthesis of two new volatile complexes, Pd(L¹)₂ and Pd(L²)₂, from sterically hindered methoxy-β-iminoketones, where HL¹ = C(CH₃)₂(OCH₃)-C(NH)-CH₂-C(O)-C(CH₃)₃; HL² = C(CH₃)₂(OCH₃)-C(NH)-CH₂-C(O)-CH(CH₃)₂. Element analysis and IR spectral data are given. The results of full X-ray crystal structure analysis of the complexes are reported. The compounds have molecular structures; the crystals of the complexes have different symmetry groups and unit cell dimensions. The Pd(L¹)₂ complex molecule has a nonplanar structure; the Pd(L²)₂ complex has a cis-structure. The geometrical characteristics obtained for the coordination units are as follows: the Pd-O and Pd-N bond lengths and N-Pd-O chelate angles were estimated at 1.960 Å, 93.7° for Pd(L¹)₂, and 1.984 Å, 1.976 Å, 92.4° for Pd(L²)₂.     

Synthesis,crystal structures and magnetic properties of two new nickel(II) complexes with α-amino acid Schiff base

Two nickel(II) complexes [Ni(napgly)(MeOH)] _n (1) and [Ni(napphe)(H₂O)₂(MeOH)] · H₂O (2), where the tridentate Schiff-base ligands H₂napgly and H₂napphe are condensed from 2-hydroxyl-1-naphthaldehyde with glycine and L-phenylalanine, respectively, were prepared and structurally characterized. In 1, two inversion-related Ni(II) ions were bridged by two O atoms from the phenolate groups of two napgly anions, forming a centrosymmetric dimeric unit which was further linked by carboxylate groups to give a two-dimensional network. Magnetic susceptibility studies performed on the complex revealed anti-ferromagnetic coupling between the metal centers. In 2, the crystal structures of the complex displayed a distorted octahedral coordination geometry in which the ONO-donor Schiff base was bonded to the metal. Intermolecular H-bonds linked the compound into a 2-D layer structure.     

Crystal structures and spectroscopic properties of copper(II)–dipicolinate complexes with benzimidazole ligands

The syntheses, crystal structures and spectroscopic properties of three Cu(II)–dipicolinate complexes with benzimidazole ligands, namely [Cu(bzim)(dipic)(MeOH)] (1), [Cu₂(2-Etbzim)₂(dipic)₂]_n·0.5nH₂O (2) and [Cu₂(2-ⁱPrbzim)₂(dipic)₂]_n (3), where dipic?=?dipicolinate, bzim?=?1-H-benzimidazole, 2-Etbzim?=?2-ethyl-1-H-benzimidazole and 2-iPrbzim?=?2-isopropyl-1-H-benzimidazole, are reported. Crystal structure studies revealed different coordination modes of the dipicolinate ligands; tridentate chelating for monomeric complex 1, and both tridentate chelating and bridging for similar polymeric complexes 2 and 3. Polymers 2 and 3 both contain two units, in which the Cu(II) central atoms Cu1 and Cu2 have different coordination polyhedra. The first unit {Cu(dipic)₂} with Cu1 is connected to the second via two bidentate carboxylate groups of an μ₃-bridging dipicolinate. In the second unit, Cu2 is coordinated by two imidazole nitrogen atoms from 2-ethyl-1-H-benzimidazole (2) or 2-isopropyl-1-H-benzimidazole (3) ligands. Complex 2 is of higher symmetry and has a localized Cu(II) atom Cu2 in a special position on the twofold axis. EPR spectra of all three Cu(II) complexes, which were measured at both room temperature and 98 K, indicate distorted tetragonal coordination spheres for all the Cu(II) atoms. The g-factor relation (g_//>?g_┴?>?2.0023) is consistent with a \(d_{{x^{2} - y^{2} }}\) ground electronic state in each case.     

2,4′-Bipyridyl complexes with cobalt(II) and nickel(II)

Summary Complexes of empirical formulae [ML₂Cl₂(OH₂)₂], [CoL₂Br₂(OH₂)₂]L·4H₂O, [NiL₂Br₂(OH₂)₂]L₂·2H₂O, [ML₂(OH₂)₄]L₂(NO₃)₂ and [ML₄(OH₂)₂](ClO₄)₂·2H₂O (M = Co^II, Ni^II, L = 2,4-bipyridyl) were synthesized and characterized by elemental and spectral analyses. The thermal decomposition of the complexes was also investigated.Author to whom all correspondence should be directed.     

Cobalt(III), nickel(II) and copper(II) complexes of N,N′-didodecildithiooxamide

The complexes of N,N′-didodecildithiooxamide (L): CoL₃(ClO₄)₃, NiL₂X₂ (X = Cl, Br, I, ClO₄, HSO₄), CuL₂X₂ (X = ClO₄, HSO₄) and CuLX₂ (X = Cl, Br) were prepared. The cobalt and nickel complexes are diamagnetic, with octahedral and planar coordination respectively. The copper complexes are paramagnetic with normal magnetic moments corresponding to a tetragonal coordination. The i.r. and far i.r. spectra are discussed.     

Cobalt(II) and copper(II)-diphenate complexes with 4-methylimidazole: linkage isomerism and weak C–H···Cu interaction

New Co(II) and Cu(II) diphenate complexes with 4-methylimidazole were synthesized and characterized through elemental analysis, magnetic susceptibilities, and IR spectroscopic studies. The crystal structures of [Co(dpa)(5-meim)₄]·2H₂O (1) and [Cu(dpa)(4-meim)(5-meim)₂]·H₂O (2) were determined by single-crystal X-ray diffraction (H₂dpa = diphenic acid, 4-meim = 4-methylimidazole and 5-meim = 5-methylimidazole). In 1, Co(II) has distorted octahedral geometry with four 5-meim and one diphenate ligands. Complex 2 has distorted trigonal bipyramidal geometry with one 4-methylimidazole, two 5-methylimidazole, and one diphenate ligands. In the complexes, the diphenate is coordinated to the metal(II) ions via the deprotonated oxygens of carboxylate as a bidentate ligand. The 4-meim and 5-meim linkage isomers within the same complex are found, and this complex is an unusual example. Moreover, another interesting feature of 2 is the presence of C–H···Cu weak hydrogen-bonding interactions.     

Synthesis and crystal structure of new cobalt(II) and copper(II) complexes with deprotonated N -[2′-(4-methyl) pyrimidinyl]-2-nitrobenzenesulfonylurea

Cobalt(II) and copper(II) complexes with deprotonated N-[2′-(4-methyl)pyrimidinyl]-2-nitrobenzenesulfonylurea were synthesized and their structures were characterized by IR spectrum, elemental analysis and X-ray diffraction. The deprotonated sulfonylurea is a bidentate ligand to Co(II) or Cu(II) in octahedral geometry. In the packing diagrams of the complexes, C–H ··· O hydrogen bonds are observed. The UV and fluorescence spectra of the complexes are described, and the thermogravimetric analyses of the complexes were performed.     

Synthesis,characterization, crystal structure,and DNA binding of two copper(II)–hydrazone complexes

Two new Cu(II)–hydrazone complexes, [Cu(L)(Hbpe)ClO₄]·ClO₄·[Cu(L)Cl] (1) and [Cu(HL)₂]·1.5ClO₄·0.5OH (2) (where HL?=?(E)-N′-(1-(pyridine-2-yl)ethylidene)benzohydrazide and bpe = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene), have been synthesized and characterized by physicochemical methods. The structures of the complexes have been established by single-crystal X-ray diffraction direct methods, which reveal that the metal ions have distorted square-pyramidal and square-planar geometries in 1, and a distorted octahedral geometry in 2. DNA binding of HL, 1, and 2, performed by UV–vis titration in tris-buffer medium, yielded binding constants, which are 9.5 × 10³, 1.88 × 10⁴, and 4.66 × 10⁴ M^?1, respectively. Viscosity measurements suggest a surface or groove-binding mode of interaction between CT-DNA with HL, 1, and 2.     

The coordination chemistry of divalent cobalt,nickel and copper—IX: The crystal structure and characterisation of a cationic 5-coordinate Cu(II) complex

The preparation, properties and X-ray crystal structure of [Cu(ttda)(tmen)](ClO₄)₂, a complex of divalent copper perchlorate with the ligands N,N,N′,N′-tetramethyl-1,2-diaminoethane (tmen) and bis-(N,N′-dimethyl-acetamido)thioether(ttda) are reported. The crystals are monoclinic with a = 15.35(1), b = 15.04(1), c = 10.91(1) A, β = 98.74(2)°, four formula units per unit cell and space group P2₁/n. The complex cation is shown to be penta-coordinate with a distorted square pyramidal geometry. Comparison is made with the properties and structure of the previously reported CuCl₂·ttda.