Synthesis and crystal structure of bis{(μ-chloro)-chloro-[N-benzoyl-N′-(2-hydroxyethyl)thiourea] mercury(II)}

The complex bis{(µ-chloro)-chloro-[N-benzoyl-N′-(2-hydroxyethyl)thiourea] mercury(II)} was prepared by reaction of HgCl₂ with N-benzoyl-N′-(2-hydroxyethyl) thiourea(HL). The compound was characterized by IR and ¹H?NMR spectroscopy and its structure was determined by single crystal X-ray diffraction. The complex is binuclear with two Hg(II) ions tetrahedrally coordinated by a terminal chloride, two bridging chlorides and a HL molecule. The Hg(II) ion is coordinated with HL via S(1).     

Crystal structure and magnetic properties of catena-μ-(pyrazine-N,N′)bis[(p-nitrobenzoyl)trifluoroacetonato-O,O′]copper(II)

The X-ray crystal structure, variable-temperature magnetic susceptibilities and e.s.r. spectra are reported for the title complex. The complex crystallises as infinite chains in which the copper(II)-β-diketonate units are bridged axially by ambidentate pyrazine ligands with a Cu⋯Cu separation of 7.6700(2) Å. The magnetic susceptibility measurements in the range 5–325 K are consistent with the ferromagnetic intrachain exchange. The S=1/2 Heisenberg ferromagnetic linear chain analysis results in magnetic parameters of g=2.12 and J/k=0.6 K.     

The crystal and molecular structures of di-μ-hydroxy-bis(di-2-pyridylamine)dinitratodicopper(II) and aqua-μ-formato-triformato-bis(di-2-pyridylamine)dicopper(II) monohydrate

The preparation, magnetic and spectroscopic properties, crystal and molecular structures of binuclear complexes of formulae [Cu₂(dpyam)₂(OH)₂(ONO₂)₂] (I), [Cu₂(dpyam)₂(O₂CH)₄(OH₂)].H₂O (II) are described. (I) consists of pairs of copper atoms linked by two hydroxo bridges. The co-ordination geometry at each copper atom is distorted square-pyramidal, the basal plane consisting of two hydroxo oxygen atoms and two nitrogen atoms from a dpyam ligand, while the axial co-ordination sites are occupied by nitrate oxygen atoms. The copper(II) ions in (II) are also in a distorted square-pyramidal environment. They are bridged by a formate group in an anti–syn configuration from a basal position to an axial position, while another axial position is occupied by the water oxygen atom. From magnetic susceptibility measurements at room temperature, both complexes are found to exhibit antiferromagnetic interactions and some magneto-structural trends are discussed.     

Metal-phosphine chalcogenide interactions. Crystal and molecular structures of [di-μ-iodo-bis{(methyl cyanide-N)(triphenylthiophosphorane-S)copper(I)}] and [di-μ-chloro-bis{μ-1,2-ethylenebis(diphenylphosphine selenide-Se,Se)} dicopper(I)]

Complexes of Cu^I with tertiary phosphine chalcogenides are described. CuI reacts with Ph₃PS in MeCN/CH₂Cl₂ to form {CuI(Ph₃PS)(MeCN)} and CuCl reacts with 1,2-ethylene-bis(tertiary phosphine selenide) {dpeSe₂} in MeCN to yield {CuCl(dpeSe₂)}. Both compounds exist as halogen-bridged centrosymmetric dimers: [Cu₂(-I)₂-(Ph₃PS)₂(MeCN)₂] (1) and [Cu₂(-Cl)₂(dpeSe₂)₂] (2) respectively. Compound (1) has almost symmetric Cu—I bonds, d(Cu—I) = 2.6503(8) Å and d(Cu—I) = 2.7196(9) Å, and each Cu is further bonded to a S atom [d(Cu—S) = 2.3444(13) Å] from Ph₃PS and to a N atom [d(Cu—N) = 2.030(5) Å] from MeCN. Compound (2) has unequal Cu—Cl bonds, 2.6390(19) and 2.2806(18) Å and nearly equal Cu—Se bonds [2.4042(11) and 2.4060(11) Å]. The geometry about each Cu center in both cases is distorted tetrahedral. The Cu—Cu bond distance in (2) is 3.249(2) Å as compared with 3.4141(16) Å in (1). MeCN is bonded strongly to Cu^I as the excess of Ph₃PS failed to remove it from the coordination sphere. Compound (2) represents the first structurally characterised example of copper(I) with a bis(tertiary phosphine selenide) (dpeSe₂) acting as a bridging ligand.     

Synthesis,characterization and nucleolytic property of bis(N,N′-dimethylglycinato)copper(II)

Aquabis(N,N-dimethylglycinato)copper(II) dihydrate, [Cu(dmg)₂(H₂O)]·2H₂O, has been synthesized and characterized by elemental analysis, FT-IR, magnetic data, thermal analysis, solution UV-visible spectroscopy, X-ray crystal structure analysis and electrospray ionization mass spectroscopy. The square pyramidal copper(II) complex crystallizes in the orthorhombic space group P2₁2₁2₁. The complex cleaves circular plasmid DNA (pBR322) in the presence of H₂O₂. The extent of cleavage varies with the concentration range of the complex, the type of buffer used, pH of buffer and the concentration of H₂O₂. Hydroxyl radical scavenger can inhibit the nucleolytic ability of this complex.     

Crystal structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ2-chloro)hexachlorodimercurate(II)

The crystal and molecular structure of bis(α,α′-dithio-bis(formamidinium)) bis(μ₂-chloro)hexachlorodimercurate(II) C₄H₁₆Hg₂Cl₈N₈S₄ (I), where α,α′-dithio-bis(formamidine) is C₂H₆N₄S₂, was solved. Crystals are monoclinic, a = 8.6417(6) Å, b = 14.648(1) Å, c = 10.2111(8) Å, β = 104.949(1)°, V = 1248.8(2) ų, space group P2₁/n, Z = 4. The crystal structure is built of HgCl ₄ ^2? ions linked via inversion centers into [Hg₂Cl₈]^4? pairs and C₂H₈N₄S ₂ ²⁺ cations. [Hg₂Cl₈]^4? anions and C₂H₈N₄S ₂ ²⁺ cations form alternating layers linked by N-H…Cl hydrogen bonds into a framework structure.     

Synthesis and magnetic properties of copper(II)-cobalt(II) complexes ofN,N′-1,2-propanedisalicylamidatocuprate(II)

Summary The binuclear metal complexes [Cu(sampn)Co(L)₂] (L=bipy, phen), have been prepared by the reaction of sodiumN,N-1,2-propanedisalicylamidatocuprate(II) heptahydrate, Na₂[Cu(sampn)] 7H₂O, with a divalent metalion, and 2,2-bipyridine or 1, 10-phenathroline. The complexes were characterized by variable-temperature magnetic susceptibility measurements; the results indicate that a weak antiferromagnetic spin-exchange interaction operates between the metal ions.     

Two 2-D copper(II) azido compounds: catena -poly[ di -μ1,1- azido,di -μN,O-(quinolinecarboxylato)(aqua)copper(II)] and 1-D catena -poly[ di -μN,N′-(quinoxaline)copper(II)nitrate]

We synthesized three copper(II) complexes with two structurally related polydentate ligands, quinoline-4-carboxylic acid (quCOOH) and quinoxaline (qux). The structures of these complexes were determined using X-ray single crystal crystallography. Complex 1, [Cu(quCOO)(N₃)(H₂O)] _n , has a 2-D polymeric structure through di-μ_1,1 azido groups forming (Cu₂N₂) dimeric units and di-μ_N,O quinoline carboxylate bridging the binuclear copper units. [Cu(quCOO)(N₃)(H₂O)] _n · 0.87MeOH, (2), has the same structure as 1 in addition to MeOH molecules separating the 2-D sheets of [Cu(quCOO)(N₃)(H₂O)] _n . [Cu(qux)(NO₃)₂] _n , (3), has no coordinated azido groups, but the quinoxaline is a bidentate bridging ligand giving a 1-D chain, while the μ_O,O′ chelating nitrato groups stabilize the chain structure by forming a square planar coordination sphere around copper. IR and UV–Vis spectra of the complexes are in agreement with the crystal structures.     

Crystal structure of di-μ-amido-bis[diammineplatinum(II)] nitrate

Di-μ-amido-bis[diammineplatinum(II)] nitrate (1) was synthesized as a byproduct during preparation of tetraammineplatinum(II) nitrate. One possible pathway to produce 1 is that [(H₃N)₂Pt(μ- OH)₂Pt(NH₃)₂](NO₃)₂, a well-known complex forming on treatment of cis-Pt(NH₃)₂I₂ with AgNO₃, reacts with aqueous ammonia. The other possible pathway involves deprotonation of [Pt(NH₃)₄](NO₃)₂ to form monomeric Pt(NH₃)₃(NH₂)NO₃ followed by elimination of NH3. Crystals of 1 (from water) are monoclinic (C2/c) with a = 16.834(2) Å, b = 10.573(1) Å, c = 7.415(1) Å, β = 114.846(1)°, and Z = 4. The cationic portion consists of two symmetrical square-planar Pt centers with the inversion center at the midpoint of the Pt(1)???Pt(1A) vector. The Pt(II) ion is coordinated by four N atoms from two ammonia molecules and two bridging amido groups affording a slightly distorted square. The molecules are stacked in such a way that the planes of coordination squares turn out to be parallel to each other with a distance of 3.501 Å. Intermolecular Pt–H interaction between the μ-NH₂ hydrogens and the platinum(II) centers of the adjacent molecule are observed.     

N,N′-(1,2-phenylene)bis­(pyridine-2-carboxamide) and N,N′-(1,2-cyclohexanediyl)bis(pyridine-2-carbox­amide) toluene hemisolvate

The crystal structures of N,N′-(1,2-phenyl­ene)­bis­(pyridine-2-carbox­amide), C₁₈H₁₄N₄O₂, (I), and N,N′-(1,2-cyclo­hexane­diyl)­bis­(pyridine-2-carbox­amide) have been determined, the latter compound as the toluene hemisolvate, C₁₈H₂₀N₄O₂·0.5C₇H₈, (II). In (I), the benzene ring is nearly coplanar with one of the pyridine rings and forms a dihedral angle of 59.4 (1)° with the other. However, in (II), the dihedral angle of the two pyridine rings is 70.0 (1)°.     

Mercury(II) complexes of pyrrolidinedithiocarbamate,crystal structure of bis{[μ2-(pyrrolidinedithiocarbamato-S,S ′)(pyrrolidinedithiocarbamato-S,S ′)mercury(II)]}

Mercury(II) complexes of pyrrolidinedithiocarbamate (PDTC) having the general formula [Hg(PDTC)X] (X = Cl^?, SCN^?, and CN^?) and [Hg(PDTC)₂] have been prepared and characterized by elemental analysis, IR, and NMR. The crystal structure of [Hg(PDTC)₂] has also been determined by X-ray crystallography, showing that the complex is a centrosymmetric dimer, [Hg₂(PDTC)₄] (bis[µ²-(pyrrolidinedithiocarbamato-S,S′)(pyrrolidinedithiocarbamato-S,S′)mercury(II)]) (1). The solid-state structure of 1 contains two crystallographically equivalent Hg(II) centers in a distorted tetrahedron.     

The crystal structure of μ-Oxo-bis{diethoxy[salicylaldoximato(2-)]-tantalum(V)}

Stochiometric reaction of salicylaldoxime and tantalum or niobium ethoxide in toluene at room temperature resulted in formation of [M₂O(C₇H₅NO₂)₂(C₂H₅O)₄], M=Ta and Nb which were crystallized from CH₂Cl₂ at −5 °C and characterized by spectroscopic techniques. The molecular structures of [Ta₂O(C₇H₅NO₂)₂(C₂H₅O)₄] was determined by single-crystal X-ray diffraction and compared with molecular structure of [Nb₂O(C₇H₅NO₂)₂(C₂H₅O)₄]. The geometries at metal atoms are distorted octahedron which shared an apex through bridged oxygen. Each dianionic salicylaldoximate ligand chelates to the one metal ion through its phenolic oxygen and oximate nitrogen atoms, and to another metal ion through its oximate oxygen atom.     

Synthesis of cobalt(II), nickel(II) and copper(II) complexes with 2-(2-hydroxyphenyliminomethyl)-1-(4-methyl-phenylsulfonamido)benzene and crystal structures of {bis(methanol)[2-(2′-N-tosylaminophenyl)iminomethyl]phenolato}nickel(II) and {bis(2,2′-bipyridine)[2-(2′-N-tosylaminophenyl)iminomethyl]phenolato}copper(II)

Electrochemical oxidation of metal anodes (cobalt, copper and nickel) in acetonitrile solutions of 2-(2-hydroxyphenyliminomethyl)-1-(4-methyl-phenylsulfonamido)benzene (H₂L) gave [CoL], [CuL] and [NiL] complexes. When 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) was added to the electrolytic cell, the mixed complexes [MLL′] (M=Co, Cu, L′=bipy or M=Ni, L′=phen) were obtained. A binuclear compound of composition [Ni₂L₂(MeOH)₄] (1) was synthesized by reaction of the ligand H₂L and nickel(II) acetate in methanol. X-ray structure determination showed the compound to be binuclear, with each nickel atom coordinated to two nitrogen and two bridging phenol oxygen atoms of two dianionic ligands and two methanol molecules, in an octahedral environment. The crystal structure of [CuLbipy] (2) was determined by X-ray diffraction; with the copper atom in a distorted bipyramidal environment defined by the two bipyridine nitrogen atoms and by the phenolic oxygen and the nitrogen atoms of the dianionic ligand. The electronic and vibrational spectral data of the complexes are discussed and related to the structure.     

Molecular oxygen oxidation of carbonyl compounds by di-μ-hydroxo homobinuclear copper(II) complexes

Di-μ-hydroxo-bridged di-copper(II) complexes in aprotic media exhibit chemical properties in the oxidation reaction by molecular oxygen. Three oxidation reactions can occur without a base: oxidation of aldehydes into the corresponding acids, oxidative degradation of some carbonyl compounds into their lower homologues, and oxidative dimerisation of phenol. With a base a fourth reaction is observed: the dehydrogenation of alcohols into carbonyl compounds. Ligands, solvent and substrate structure effects are discussed.     

Synthesis,structure and magnetic studies of copper(II)-nickel(II) complexes withN,N′-bis(2-aminopropyl)oxamidocopper(II)

Three novel heterobinuclear complexes have been prepared and identified as [Cu(oxap)Ni(L)₂](ClO₄)₂·ξH₂O, where oxap denotes theN,N′-bis(2-aminopropyl)oxamido dianion and L denotes 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) or 5-nitro-1,10-phenanthroline (NO₂-phen). The crystal structure of [Cu(oxap)Ni(phen)₂]-(ClO₄)₂·2H₂O has been determined. Crystal data: triclinic, space group , a=12.079 (6), b=12.409 (4), c=17.261 (8) ?, α=70.91 (2), β=86.72 (4), γ=89.19 (3)^o. At room temperature, Z=2. The Cu^II is in a square planar environment and the Ni^II is in an octahedral environment. The Cu−Ni distance is 5.292 ?. The temperature dependences of the magnetic susceptibilities of [Cu(oxap)Ni(phen)₂]-(ClO₄)₂·2H₂O and [Cu(oxap)Ni(bipy)₂](ClO₄)₂ have been studied in the 4.2–300 K range, giving the exchange integral J=−92.4 cm⁻¹ for bipy and J=−94.3 cm⁻¹ for phen. These results are commensurate with antiferromagnetic interactions between the adjacent metal ions.     

Synthesis,crystal structure and antibacterial activity of a new binuclear copper(II) complex with N,N ′- bis ( N -hydroxyethylaminopropyl)oxamido as a bridging ligand

A new μ-oxamido-bridged dicopper(II) complex, [Cu₂(heap)](ClO₄)₂?·?2H₂O [H₂heap?=?N,N′-bis(N- hydroxyethylaminopropyl)oxamido], has been synthesized and structurally characterized by elemental analyses, molar conductance, IR and single-crystal X-ray diffraction. The single crystal X-ray analysis reveals that the asymmetric unit of the complex is composed of half a binuclear cation [Cu₂(heap)]²⁺, one perchlorate anion, and one lattice water molecule. Each copper(II) atom is tetracoordinate in a distorted square-planar geometry and the bridging ligand (H₂heap) adopts the trans conformation with an inversion centre at the middle of the C2–C2ⁱ bond. The structure cohesion is ensured by hydrogen bonding interactions, which form a two-dimensional supramolecular framework. The antibacterial assay indicates that the complex showed better activity than the ligand.     

Five coordinate complexes of N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamide with copper Crystal and molecular structures of dichloro(N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamido)copper(II) and chloro(perchlorato)(N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamido)copper(II)

The title compound N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamide (DEAP) forms a 1:1 complex with anhydrous CuCl₂, [Cu(DEAP)Cl₂], (1) which was crystallized from EtOH solution in the monoclinic space group P2_{1/ n} with cell constant, a = 10.024(1); b = 13.122(1); c = 14.404(1) Å β = 101.31(1)° V = 1857.8(3) ų and Z = 4. The chloro-perchlorato complex, [Cu(DEAP)Cl(ClO₄)], (2) obtained in near quantitative yield by reacting (1) with an excess of NaClO₄ in EtOH, crystallized in the monoclinic space group P2_{1/ n} with cell constants, a = 7.965(1); b = 25.827(2); c = 10.046(1) Å β = 98.81(1)° V = 2042.2(4) ų and Z = 4. Both (1) and (2) contain 5-coordinated copper linked to DEAP through O～N～O donor set of atoms with covalently bonded chlorine atoms in (1) and chlorine and perchlorate groups in (2). The coordination geometry is intermediate between square pyramidal and trigonal bipyramidal, and is probably best described as a trigonally distorted rectangular pyramid.     

Synthesis and crystal structure of bis[(18-crown-6)potassium] bis(μ2-bromo)tetrabromodicopper(II)

A new complex bis[(18-crown-6)potassium] bis(μ₂-bromo)tetrabromodicopper(II), [{K(18-crown-6)}₂Cu₂Br₆] (I), is synthesized and studied by X-ray diffraction analysis (space group P2₁/n, a = 9.137 Å, b = 34.860 Å, c = 13.414 Å, β = 99.53°, Z = 4). The structure is solved by a direct method and refined by the fullmatrix least-squares method in the anisotropic approximation to R = 0.083 for 5850 independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). Complex molecule I consists of the central binuclear anion [Cu₂Br₆]^2? and two peripheral cations K(18-crown-6)]⁺ of the host-guest type bound to the [Cu₂Br₆]^2? anion through two and one K-Br coordination bonds. In the [Cu₂Br₆]^2? anion, the coordination polyhedra of two Cu atoms can be described as strongly flattened tetrahedra. In two [K(18-crown-6)]⁺ fragments, the coordination polyhedra of their K⁺ cations (coordination numbers 8 and 7) are distorted hexagonal pyramids with a base of six O atoms of the 18-crown-6 ligand and a bifurcated or ordinary vertex: the Br atoms of the [Cu₂Br₆]^2? anion. Two 18-crown-6 ligands have a standard crown conformation.