Synthesis and Structure of Copper(II) Complexes with Methyl [(Pyrazolo-1-carbothioyl)-amino]propionate Derivatives

Methyl 3-[(3,5-dimethylpyrazole-1-carbothioyl)-amino]propionate (L¹) and the optically active derivative of natural monoterpene (+)-3-carene, (3bS,4aR)-3-[(3,4,4-trimethyl-3b,4,4a,5-tetrahydro-cyclopropa[3,4]cyclopenta[1,2-c]pyrazole-1-carbothioyl)-amino]propionate (L²), are synthesized. The paramagnetic CuL¹Cl₂ (I) and [Cu₂L² ₂Cl₄] (II) complexes are obtained. According to the X-ray diffraction data, in mononuclear complex I, the L¹ molecule performs a bidentate-cyclic function due to the coordination of the S atom of the C=S group and the N atom of the pyrazole cycle. The CuCl₂NS coordination polyhedron is a distorted tetrahedron. Two molecules of complex I form an associate due to weak Cu···S interactions. Compound II is binuclear due to the bridging function of two Cl^- ions, and analogous functions of the L¹ and L² ligands. The coordination polyhedron in complex II is CuCl₃NS. The _eff values for compounds I and II are equal to 1.81 and 1.79 _B, respectively, and are constant in the interval from 78 to 300 K, indicating that noticeable exchange interactions between unpaired electrons of the Cu²⁺ ions are absent. The EPR spectra of the complexes in the solid phase are examined.     

Synthesis and structure of binuclear compounds of copper(I) with [(3,5-dimethylpyrazole-1-carbothioyl)-amino]-carboxylic esters

New coordination compounds of copper(I) have been synthesized: [Cu₂L ₂ ¹ Cl₂] (I) and [Cu₂(HL²)₂Br₂] (II), where L¹ is methyl 3-[(3,5-dimethyl-pyrazole-1-carbothioyl)-amino]-propionate, and HL² is ethyl [(3,5-dimethyl-pyrazole-1-carbothioyl)-amino]-acetate. X-ray diffraction analysis showed that the crystal structures of these compounds are built from binuclear molecules. The L¹ and HL² molecules perform the bridging tridentate cyclic function, which results in a closure of two five-membered chelate cycles CuN₂SC and metallocycle Cu₂S₂. Each Cu atom coordinates the N atom of the pyrazole ring, the halogen atom (Cl in I and Br in II), and two S atoms, thus forming a distorted tetrahedron. The Cu₂S₂ metallocycles, the CuN₂SC chelate cycles, and the pyrazole rings are flat. Both CuN₂SC chelate cycles are almost perpendicular to the Cu₂S₂ metallocycle and form a chair conformation. Redox reactions in CuCl₂·2H₂O-L¹-ethanol and CuBr₂-HL²-ethanol systems were examined by EPR spectroscopy.     

Synthesis and Characterization of Nickel(II) and Copper(II) Complexes with Non-symmetric Tetraaza[14]annulene Derivatives. X-ray Crystal Structure of Copper(II) Complex

The complexes 13,14-([X]benzo)-3-(p-[Y]benzoyl)-2,4,9,11-tetramethyl-1,5,8,12-tetraazacyclotetradeca-l,3,9,11-tetraenato(2-)nickel(II), wherein Y = CH₃, H, Cl, NO₂ or OCH₃, X = CH₃ or Cl, have been synthesized and characterized. IR spectra of the benzoylated complexes show intense bands in the regions 1641-1654 cm^?1 attributable to the stretching modes of C—O. Hammett plots of the l/γ _max of π→π ^? have positive slopes of 0.251 for A series (X = CH₃) and 0.233 for B series (X = Cl), respectively, which are quite similar to those based on the NMR resonances of methine protons. The cyclic voltammograms of the complexes show two one-electron irreversible oxidation processes in the potential range of +0.1 to +0.8 V and two, three or four reduction peaks between ?1.2 and ?2.8 V depending on the substituents. Hammett plots of first and second oxidation potentials are linear with the positive slopes (0.039 and 0.057 V for A series, 0.036 and 0.047V for B series). The structure of the copper(II) complex (orthorhombic, C222₁, a= 8.0994(11), b= 8.3187(10), c= 24.561(5)Å, α(=β=γ)= 90.0°, Z= 4, R ₁= 0.0474 and wR ₂= 0.1219) was characterized using single crystal X-ray diffraction method.     

Synthesis and Structure of Copper(II) Phosphonodithioite Complexes

A series of new complexes of CuBr with phosphonodithioites were prepared and characterized by NMR and IR spectroscopy. As shown by single crystal X-ray diffraction, diethyl tert-butylphosphonodithioite forms with CuBr a tetrameric cubane-like complex with the monodentate coordination of the organophosphorus ligand via the P atom.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 903–907.Original Russian Text Copyright © 2005 by Kursheva, Kataeva, Perova, Batyeva, Sinyashin, Freilich.     

Synthesis of Ethyl 2,2-Bis{[(benzoylcarbamothioyl)oxy]methyl}propanoate and Its Complexes with Copper(II) and Cobalt(II) Ions

Russian Journal of General Chemistry - The structures of ethyl 2,2-bis{[(benzoylcarbamothioyl)oxy]methyl}propanoate and its 1 : 1 complexes with copper(II) and cobalt(II) ions were determined by...     

Synthesis of Novel Tridentate 5-Arylazosalicylaldehyde Thiosemicarbazone Derivatives and Their Complexes with Copper(II)

Russian Journal of General Chemistry - Herein, novel 5-arylazosalicylaldehyde thiosemicarbazone derivatives (H2L1–12) and their copper(II) complexes have been synthesized and characterized by...     

Halido-bridged Copper(II) Complexes with 1-tert-Butyl-1H-tetrazole: Crystal Structure and Magnetic Properties

Complex [Cu(tbt)Cl₂]_n (tbt = 1-tert-butyl-1H-tetrazole) was prepared by reaction of tbt with copper(II) chloride in solution. According to single-crystal X-ray analysis, this complex presents 1D coordination polymer, formed at the expense of double chlorido bridges between neighboring pentacoordinate copper(II) cations. 1-tert-Butyl-1H-tetrazole acts as monodentate ligand coordinated by Cu^II cations via the heteroring N⁴ atoms. The temperature-dependent magnetic susceptibility measurements of novel complex [Cu(tbt)Cl₂]_n as well as described previously 1D coordination polymer [Cu(tbt)₂Cl₂]_n, and linear trinuclear complex [Cu₃(tbt)₆Br₆], were carried out. Magnetic studies revealed that the copper(II) ions were weakly ferromagnetically coupled in polymeric copper(II) chloride complexes, whereas complex [Cu₃(tbt)₆Br₆] showed antiferromagnetic coupling.     

Synthesis, Crystal Structure and Properties of Polyamine Copper(II) Complexes

Two polyamine copper(II) complexes were synthesized by the reaction between N,N,N′,N′-tetrakis(2′-aminoethyl)propane-1,2-diamine hexahydrochloride and copper(II) perchlorate under almost the same conditions except for reaction temperature. The crystal structures of two complexes were determined by X-ray diffraction techniques, which shows that one of the complexes is unexpected and is a double chlorine or chloride-bridged dinuclear copper(II) complex formed by two diethylenetriamines, and another is a pentadentate mononuclear copper(II) complex composed of homo-protonated N,N,N′,N′-tetrakis(2′-aminoethyl)propane-1,2-diamine. The mechanism of the reaction leading to form the unexpected complex was discussed. The UV-visible spectra and cyclic voltammogram of the complexes were measured.     

Synthesis and antibacterial activities of copper(II) with [(2-hydroxy-3,5-diiodo-benzylidene)-amino]-acetic acid

A new tridentate ligand, [(2-hydroxy-3,5-diiodo-benzylidene)-amino]-acetic acid (HDBA), has been synthesized from 3,5-diiodosalicylaldehyde and glycine in ethanol. A 1-D coordination polymer has been synthesized by reaction of HDBA with Cu(Ac)₂ · H₂O in ethanol–water. The complex was characterized by UV, IR, ESI–MS, elemental analyses, and X-ray crystallography. The central copper(II) is five-coordinate by one nitrogen and two oxygens from HDBA, one oxygen from water, and one oxygen from another HDBA. The complex was assayed for antibacterial (Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Enterobacter cloacae) activities by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Complex 1 showed favorable antimicrobial activity with minimum inhibitory concentrations of 6.25, 6.25, 3.125, 6.25, 6.25, and 3.125 µg mL^?1 against B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli, and E. cloacae, respectively.     

Novel Copper(II) Complexes with Dipinodiazafluorene Ligands: Synthesis,Structure, Magnetic and Catalytic Properties

The reactions of CuX₂ (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX₂L₁]₂ (X = Cl (1), Br (2), L₁ = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b’]diquinolin-12(2H)-one) and [(CuX₂)₂L₂]n (X = Cl (3), Br (4), L₂ = (1R,3R,8R,10R,1’R,3’R,8’R,10’R)-2,2,2’,2’,9,9,9’,9’-Octamethyl-1,1’,2,2’,3,3’,4,4’,7,7’,8,8’,9,9’,10,10’-hexadecahydro-1,3:1’,3’:8,10:8’,10’-tetramethano-12,12’-bi(cyclopenta [1,2-b:5,4-b’]diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1, 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1–2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L₂. All complexes contain a binuclear fragment {Cu₂(μ-X)_2×2} (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-N_ax distance is elongated compared to Cu-N_eq. The EPR spectra of compounds 1–4 in CH₃CN confirm their paramagnetic nature due to the d⁹ electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2, the effective magnetic moments are µ_eff ≈ 1.87 and 1.83 µ_B (per each Cu²⁺ ion), respectively, in the temperature range 50–300 K, which are close to the theoretical spin value (1.73 µ_B). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu₂(μ-X)₂X₂} (X = Cl, Br) dimers (J/k_B ≈ 25 and 31 K for 1 and 2, respectively) or between dimers (θ′ ≈ 0.30 and 0.47 K for 1 and 2, respectively) were found at low temperatures. For compounds 3 and 4, the magnetic susceptibility is well described by the Curie–Weiss law in the temperature range 1.77–300 K with µ_eff ≈ 1.72 and 1.70 µ_B for 3 and 4, respectively, and weak antiferromagnetic interactions (θ ≈ −0.4 K for 3 and −0.65 K for 4). Complexes 1–4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides.     

Synthesis and Structure of Different-Metal Different-Ligand Germanium(IV) and Cobalt(II) or Copper(II) Complexes with 1-Hydroxyethylidenediphosphonic Acid and 1,10-Phenanthroline

Different-metal different-ligand complexes [{Co(Phen)₃}₂{Co(Phen)(H₂O)₄}₂][{Ge(μ-OH)(μ- Hedp)}₆Cl₂] (I), [{Cu(Phen)₂(H₂O)}₂(HPhen)₂][Ge(μ-OH)(μ-Hedp)]₆ · 20H₂O (II) (H₄Hedp = 1-hydroxyethylidenediphosphonic acid, Phen = 1,10-phenanthroline) were synthesized and studied by X-ray diffraction. According to X-ray diffraction data (CIF files CCDC nos. 1573112 (I), 1573113 (II)), compounds I and II are cation–anion type complexes in which the anions are represented by {[Ge(μ-OH)(μ-Hedp)]⁶}^6– and, in the case of I, two additional Cl^– ions, while the cations are [Co(Phen)₃]²⁺, [Co(Phen)(H₂O)₄]²⁺ in I and [Cu(Phen)₂(H₂O)]²⁺, HPhen⁺ in II. In the crystals of compounds I and II, the cations, anions, and water molecules are combined by numerous intermolecular hydrogen bonds, giving rise to a 3D network.     

Synthesis and Optical Properties of Ethyl 2-Cyano-2-[3,4-dicyanopyridin-2(1H)-ylidene]acetate Derivatives

Russian Journal of Organic Chemistry - Derivatives of ethyl 2-cyano-2-[3,4-dicyanopyridin-2(1H)-ylidene]acetate have been synthesized by reaction of 2-chloropyridine-3,4-dicarbonitriles with ethyl...     

Copper(II) Cyanoacetate Polymer: Synthesis and Structure

A new copper carboxylate polymer with cyanoacetate anion as a ligand was synthesized and studied using X-ray diffraction, IR, and EPR spectroscopy. The crystal is tetragonal: a= 14.702(2) Å, c= 13.470(3) Å, Z= 8, space group I4₁/a, and R= 0.0634. The copper atoms in the centrosymmetric dimeric fragment have a square-pyramidal surrounding with the CuO₄N coordination core and are joined through four bidentate bridging anions of cyanoacetic acid Cu(1)"–O(1A) 1.931(4) Å, Cu(1)"–O(1B) 1.926(4) Å, Cu(1)–O(2B) 2.018(3) Å, Cu(1)–O(2A) 2.036(4) Å, and Cu(1)–N(1A)" 2.206(5) Å). The Cu···Cu" distance in the dimer is 2.709 Å. The copper atom is extended from the mean equatorial plane toward the axial nitrogen atom by 0.23 Å. EPR data confirm strong antiferromagnetic interaction (2J –275 cm^–1) between the copper(II) ions of the dimeric fragment, whereas the interaction between the dimers is significantly weaker (J< 0.3 cm^–1).     

三氟甲基磺酸铜(II)手性衍生物:不对称合成中的一类高效催化剂

三氟甲基磺酸铜 [Cu(OTf) 2 ]与各种手性磷氮配体络合催化不对称合成已取得了巨大进展 .详细评述了近五年来该类手性铜催化剂在各种不对称催化反应中的最新应用     

萘基修饰二乙烯三胺配体的合成、铜离子键合及核酸酶活性

本文合成了两个具有平面萘环的二乙烯三胺配体：4-(α-萘甲基)-二乙烯三胺(L¹)和4-( β-萘甲基)-二乙烯三胺(L²)，用元素分析、NMR和ESI-MS等技术分别对它们进行了表征。通过电位滴定研究了这些配体的酸离解常数，它们与Cu(Ⅱ)离子结合的配位水分子的酸离解常数pK_a值，与未修饰的二乙烯三胺的铜配合物相比，配合物的配位水分子的酸离解常数pK_a值分别降低了1.09和0.59。这有利于配合物在接近生理pH值条件下对磷酸二酯键进行亲核活化。通过观察配体及其铜配合物对小牛胸腺DNA的粘度影响，证明配体和配合物可能以插入和部分插入两种方式与DNA作用。在无任何还原物质存在的条件下研究了两配体的铜配合物对质粒pBR322 DNA的断裂，结果表明两个配合物都能够有效切割超螺旋DNA为缺刻型DNA，且L¹的铜配合物具有更高的核酸酶活性。     

三氟甲磺酸铜催化新型苯并恶唑烷衍生物的合成

以三氟甲磺酸铜［Cu(OTf)₂］为催化剂,取代邻氨基苯酚(1a~1g)和取代联苯甲酰(2a~2g)为原料,合成了7个苯并恶唑烷衍生物（3a~3g,其中3b~3g为新化合物）,其结构经¹H NMR, ¹³C NMR, IR和HR-MS(ESI)表征。以3a的合成为例,研究了催化剂、溶剂、催化剂用量、物料比γ［n(1) : n(2)］和反应温度对3产率的影响。结果表明：在最佳反应条件［8 mmol%Cu(OTf)₂, 1,2-二氯乙烷为溶剂,1a~1g1.5 mmol, γ=3:1,于70 ℃反应10 h］下,3a~3g产率62%~91%。     

Copper(II) Nitrate Complex with Acrylamide: Synthesis and Crystal Structure

The molecular structure of a copper(II) nitrate complex with acrylamide (AA), Cu(NO₃)₂· 4(CH₂=CHC(O)NH₂), was determined using X-ray diffraction analysis. The coordination of AA involves the carbonyl O atom (Cu–O 1.952–1.958 Å). The X-ray study revealed the structural features of the compound that determine its chemical properties and prevent its frontal polymerization.     

Nickel(II) and Zinc(II) Complexes with Benzoylacetaldehyde Derivatives

Russian Journal of Coordination Chemistry - Ni(II) and Zn(II) complexes, [M(Ln)A] (n = 1–3, A = NH3, Py), were prepared from the products of condensation of benzoylacetaldehyde with aromatic...     

Binuclear Copper(II) Complexes with Terpene Bicyclic Optically Active Iminoalcohol: Synthesis,Structure, and Magnetic Properties

Methods were developed for synthesizing the 3-Carene derivative (1R)-1-|(1R,2R,5R)-2-benzyl-3-imino-6,6-dimethylbicyclo[3.1.0]hex-2-yl}-ethanol (HL) and stable copper(II) complexes [Cu₂(H₂O)L₂(CH₃COO)₂] · H₂O (IV), [Cu₂L₂Cl₂] (V), and [Cu₂L₂Br₂] (VI). According to X-ray diffraction data, IVand Vhave molecular binuclear structures with a planar Cu₂O₂cycle. The CuOCu angles are equal to 102.2°, 102.8° (IV) and 103.2°, 103.8° (V). The L^–terpene ligand acts as a tridentate cyclic bridge. A strong antiferromagnetic exchange interaction between the unpaired electrons of the copper(II) ions was detected in compounds IV–VIusing the static magnetic susceptibility method. The –2Jparameter for IV, V, and VIis equal to 660, 1000, and 1060 cm^–1, respectively.     

Synthesis and Characterization of Tris(oxazolinyl)borato Copper(II) and Copper(I) Complexes

The reaction of To^MTl (To^M=tris(4,4-dimethyl-2-oxazolinyl)phenylborate) and CuBr₂ in benzene at 60 °C provides To^MCuBr ( 1 ) as an entry-point into tris(oxazolinyl)phenylborato copper chemistry. To^MCuO^tBu ( 2 ) and To^MCuOAc ( 3 ) are prepared by the reactions of To^MCuBr with KO^tBu and NaOAc, respectively. To^MCuO^tBu is transformed into (To^MCuOH)₂ ( 4 ) through hydrolysis. NMR, FT-IR, and EPR spectroscopies are used to determine the electronic and structural properties of these copper(II) compounds, and the solid-state structures were characterized by X-ray crystallography. Reduction of copper is observed upon treatment of To^MCuO^tBu with phenylsilane in an attempt to synthesize monomeric copper(II) hydride. To^MCu ( 5 ) and To^M₂Cu ( 6 ) were independently synthesized and characterized for comparison.