Dependence of the Structure and Properties of (M,Cu)Sr2(Ln,Ca)Cu2O8−δ (1212) and (M,Cu)Sr2(Ln,Ce4+)2Cu2O10−δ (1222) Phases on the Cation M

The composition and structure of (M,Cu)(Sr,Ln)₂(Ln,Ca,Sr)Cu₂O_8– phases, where M = B, Al, Cr, Pb, Bi, Ru, or Mo (1212 type), and (M,Cu)(Sr,Ln(₂(Ln,Ce⁴⁺)₂Cu₂O_10– phases, where M = V, Cr, Mn, Ru, or Mo (1222 type), have been determined. The role of the M cation in the formation of the crystal structures and the superconductivity phenomenon was analyzed. The relationship between the type of M cation and structural parameters was discovered.     

Ba2Ca2Cu3Ox Precursor Effects on Synthesis of (Hg,Pb)Ba2Ca2Cu3O8+δ Superconductor

The influence of Ba₂Ca₂Cu₃O_x precursor on the synthesis and properties of (Hg,Pb)Ba₂Ca₂Cu₃O_8+δ has been examined. Fine homogeneous Hg-free precursor powder of Ba₂Ca₂Cu₃O_x of desirable phase composition was prepared by sol-gel method using EDTA acid as a complexing agent. A reproducible superconducting sample of Hg_0.8Pb_0.2Ba₂Ca₂Cu₃O_8+δ with fine-grained, dense microstructure, composed predominantly of (Hg,Pb)-1223 phase and with advantageous magnetic properties, was synthesized by high pressure crystallization in mercury environment of well-calcined Ba₂Ca₂Cu₃O_x precursor. This revised version was published online in July 2006 with corrections to the Cover Date.     

Dta/TG study of the formation of the (Bi,Pb)2Sr2Ca2Cu3O10+δ superconductor

In order to get insight in some of the yet unanswered questions about the formation process of the (Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀₊ superconducting compound, coupled DTA-TG measurements have been performed in parallel with other techniques such as X-ray diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray Microanalysis. The path leading to the formation of the (Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀₊ compound, starting from coprecipitated oxalates powders was studied. The activation energy of some of the involved transformation processes were determined. Relationships between the differences induced in the DTA traces by various sample nominal compositions and the intergranular magnetic properties of the superconductor will be discussed.     

Synthesis,spectroscopic, and biological activities of two binuclear complexes [Cu(II)(1-phenylamidino-O-methylurea)2(H2O)]2(Cl2)2 and [Cu(II)(1-phenylamidino-O-i-butylurea)tmen]2(Cl2)2·2H2O

EPR spectra of two copper(II) binuclear complexes, [Cu(II)(1-phenylamidino-O-methylurea)₂(H₂O)]₂(Cl₂)₂ (1) and [Cu(II)(1-phenylamidino-O-i-butylurea)tmen]₂(Cl₂)₂?·?2H₂O (2), at room temperature showed fine structure transitions (ΔM _s?=?±1) and a very weak half-field signal corresponding to forbidden transitions (ΔM _s?=?±2). The spectrum of 1 showed disappearance of normal and half-field transitions when cooled to 77?K, suggesting antiferromagnetical coupling dicopper complex which is also supported by the low magnetic moments (µ _eff?=?1.64?B.M.). The isotropic exchange interaction constant J (41?cm^?1) for 2 indicated that interaction between the two spins of the binuclear complex is ferromagnetic, confirmed from the high magnetic moment value (µ _eff?=?2.25?B.M.). The binding of these complexes with calf thymus DNA suggested that these complexes interact with DNA by electrostatic or groove binding, not by intercalation. The two complexes have good antibacterial activity against tested bacteria responsible for urinary tract infection.     

Structure, DNA Binding Studies of Complex {[Cu(phen)(py)(H_2O)_2]·2H_2O}_n

A copper(II) complex of type {[Cu(phen)(py)(H₂O)₂]·2H₂O}_n (where phen=1,10‐phenanthroline, py=pyridine‐3,4‐dicarboxylate) has been synthesized by a normal temperature volatilization method and structurally determined by single‐crystal X‐ray crystallography. The crystal belongs to monoclinic system, space group P2(1)/c with the crystal cell parameters of a=7.5258(4) Å, b=12.3184(7) Å, c=21.0000(12) Å, α=90.00°, β=98.0720(10) °, γ=90.00°, V=1927.53(19) ų and Z=4. The final reliability factors are R=0.0398 and wR=0.1138 for 3771 reflections with I>2δ(I₀). Its mode of interaction with DNA and the binding constants have been determined by fluorescence, ultraviolet spectra and viscometry.     

Crystal structure of [Cu2(Edta)(Py)2(H2O)2] · 2H2O and [Cu(Im)6]{;Cu(Im)4[Cu(Edta)(Im)]2} · 6H2O, Products of the interaction of (Ethylenediaminetetraacetato)diaquadicopper(II) with pyridine and imidazole

The crystals of [Cu₂(Edta)(Py)₂(H₂O)₂] · 2H₂O (I) and [Cu(Im)₆]{;Cu(Im)₄[Cu(Edta)(Im)]₂} · 6H₂O (II) were isolated as a result of the reaction of an aqueous solutions of Cu₂(Edta) · 4H₂O with pyridine or imidazole, respectively. The crystals were studied by X-ray diffraction. The crystals of I are monoclinic, a = 12.682 Å, b = 6.788 Å, c = 14.834 Å, β = 91.44°, Z = 2, space group P2₁/n. The crystals of II are triclinic, a = 9.118 Å, b = 14.889 Å, c = 15.130 Å, α = 72.59°, β = 72.94°, γ = 82.54°, Z = 1, space group P{ie241-1}. In the centrosymmetric binuclear complex molecule of I, an N atom and two O atoms of the Edta ligand are coordinated to each Cu atom (Cu-N, 2.046 Å; Cu-O, 1.941 and 1.954 Å). The N atom of the pyridine molecule (Cu-N, 1.993 Å) completes the base of an elongated tetragonal pyramid (4 + 1) with the O atom of the H₂O molecule in the apex (Cu-O(w), 2.244 Å). The crystals of II are built of centrosymmetric complex cations [Cu(Im)₆]²⁺ (Cu(1)-N, 2.469, 2.021, and 2.056 Å), centrosymmetric trinuclear complex anions {;Cu(Im)₄[Cu(Edta)(Im)]₂}^2?, and crystal water molecules. In the anion, the central fragment [Cu(Im)₄]²⁺ (Cu(2)-N, 1.985 and 2.023 Å) is bonded to two peripheral complexes [Cu(Edta)(Im)]^2? through atoms O of the Edta ligand (Cu(2)-O, 2.615 Å). In the [Cu(Edta)(Im)]^2? fragment of the complex anion, the Cu(3) atom is bonded to the Edta ligand through the two N atoms and three O atoms (Cu(3)-N, 1.970 and 2.071 Å; Cu(3)-O, 1.966, 1.969, and 2.238 Å) and with the imidazole molecule, through an N atom (Cu(3)-N, 2.397 Å). The coordination polyhedra of the three copper atoms (Cu(1)-Cu(3)) in the structure of II are elongated tetragonal bipyramids (4 + 2). In the structures studied, Edta^4? is a hexadentate chelating/bridging ligand. However, the coordination mode of the ligand in these structures is different: in the binuclear complex I, the Edta ligand is coordinated to each Cu atom through an N atom and two O atoms with the formation of two chelate rings (symmetric (trans) coordination mode), whereas, in the trinuclear complex II, the Edta ligand is coordinated to the Cu(2) atom through an O atom and to the Cu(3) atom through the two N atoms and three O atoms with the formation of three chelate rings (asymmetric (cis) coordination mode).     

Synthesis,structure, DNA-binding,and nuclease activity of a 3d–4f mixed metal nitrosyl complex, [Pr(phen)2(MeOH)(H2O)2][Fe(CN)5(NO)] · (Phen)(DMF)(MeOH)(H2O)

A cyano-bridged heterometallic lanthanide-transition metal nitrosyl complex, [Pr(phen)₂(MeOH)(H₂O)₂][Fe(CN)₅(NO)]?·?(Phen)(DMF)(MeOH)(H₂O) (Phen?=?1,10-phenanthroline and DMF?=?dimethylformamide), has been synthesized from reaction of PrCl₃?·?6H₂O with 1,10-phenanthroline in methanol and sodium nitroprusside followed by crystallization from DMF. The crystal structure shows that the complex is a 1-D chain, stabilized by coordination, hydrogen-bonding, and π–π stacking interactions. The complex shows nuclease activity with pUC19 supercoiled DNA in DMF/Tris-HCl buffer in the presence of H₂O₂.     

Hg(PMBP)2(HPMBP)2和Zn(PMBP)(H2O)Cl配合物的合成及结构

用1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(HPMBP)与HgCl₂和ZnCl₂·6H₂O作用,分别合成化学式为[Hg(PMBP)₂(HPMBP)₂]和[Zn(PMBP)(H₂O)Cl]的配合物;用元素分析、IR、¹HNMR和电导等物理化学方法推测了配合物的分子结构式。配体在此螯合过程中皆由酮式转变为烯醇式,在Hg(Ⅱ)配合物中部分不变。     

[Cu(bpp)2(bpdc)(H2O)2]×2H2O and [Cu(bpp)2](tdc)×7.5H2O的合成、晶体结构和热稳定性

在室温下, 由Cu(NO3)2 、1,3 -二（4 -吡啶基）丙烷(bpp)、4,4 ’ -联苯二甲酸(H2bpdc)和2,5-噻吩二甲酸(H2tdc)制备出两种新型铜( II)配位聚合物[Cu(bpp)2(bpdc)(H2O)2]n·2nH2O, 1 和[Cu(bpp)2]n·n(tdc) 7.5nH2O, 2。两个配位聚合物均为一维线型结构,铜原子均采取变形的八面体结构,在轴线方向上的两个水分子与铜原子存在较弱的配位作用。在配合物1中,两个bpdc羧酸根离子与铜原子配位,而2中的tdc羧酸离子没有与铜原子键合,只是作为反离子平衡电荷。在两个产物中, 配体bpp具有不同的构象。热重分析表明配合物1与2分别在110°C和160°C以下是稳定的。     

Synthesis,spectral, thermal and structural characterization of {[Cu(H2O)3][Cu(MAL)2] · 2H2O}∞ and [Cu(MAL)(TEA)] · H2O (MAL = malonate and TEA = triethanolamine)

A polymeric malonato-bridged copper(II) complex, {[Cu(H₂O)₃][Cu(MAL)₂]· 2H₂O}, and a mononuclear malonato-copper(II) complex with triethanolamine, [Cu(MAL)(TEA)]·H₂O, have been prepared and characterized by elemental analyses, i.r., u.v.–vis, magnetic measurements and single crystal X-ray diffraction. The polymeric complex consists of one-dimensional chains containing the MAL bridged [Cu(H₂O)₃]²⁺ and [Cu(MAL)₂]^2– ions and each MAL ligand simultaneously exhibits chelating bidentate (at one copper atom) and bridging (at the adjacent copper atom) coordination modes. The intrachain Cu1...Cu2 separation is 4.963 Å and the polymeric complex exhibits antiferromagnetic behaviour. In the mononuclear complex, the copper(II) ion is octahedrally coordinated by one bidentate MAL and one tetradentate neutral TEA ligands. The i.r. spectra and thermal decompositions of both complexes are described.     

Synthesis,Crystal Structure,Fluorescence Property and Antibacterial Activity of Two Unprecedented One-dimensional Chain Metal-organic Coordination Polymers: Zn(H-SSA)(Phen)(H_2O)_2and Cu(H-SSA)(Phen)(H_2O)_2

IntroductionSalicylicacid (2 oxybenzoicacid ,H2 Sal)anditsderivativeshavebeenknownforalongtimetopossessan ti inflammatoryactivity ,1whileithasbeenfoundthatthebiologicalactivityofawidevarietyoforganicdrugsisen hancedupontheirmetalcomplexation .2 ,3Forexample ,bis(salicylato)copper(II)isastrongeranalgesicandanti inflammatoryagentforanimalsthansalicylicaciditself,4andthecopper(II)complexofaspirin ,Cu2 (aspirin) 4,isamoreeffectiveanti inflammatoryandanti rheumatoida gentthanaspirinitself.5,6 I…     

[Cu(H_2O)(phen)_2](CIO_4)_2的晶体结构

标题化合物晶体属三斜晶系;空间群为P_1;晶胞参数:a=8.182(2)A,b=10.389(2)A,c=16.261(5)A,α=99.38(2)°,β=89.97(2)°,γ=113.18(2)°;Z=2,两个phen上的四个N原子和一个配位水中的O原子围绕中心体Cu原子形成一个畸变的三角双锥构型,配位水与阴离子ClO_4~-中的O原子形成氢键。     

Synthesis,structure, and DNA-binding of a new binuclear copper(II) complex: [Cu2(heap)(H2O)2](pic)2 · 2H2O

In this study, a new μ-oxamido-bridged binuclear copper(II) complex [Cu₂(heap)(H₂O)₂](pic)₂ ? 2H₂O, where heap and pic stand for the anion of N,N′-bis(N-hydroxyethylaminopropyl)oxamide and 2,4,6-trinitrophenol, respectively, has been synthesized and characterized by elemental analyses, IR, UV, molar conductance, and single-crystal X-ray diffraction. The complex has an embedded inversion center at the middle of the C–C bond of the oxamido group. Each copper(II) is in a square-pyramidal coordination geometry. The bridging ligand (heap) adopts a bis-tetradentate trans conformation and the oxamido group is in an imidic acid configuration. Hydrogen bonds contribute to a 3-D supramolecular structure in the crystal. The interaction of the binuclear complex with herring sperm deoxyribonucleic acid (HS-DNA) has been investigated by using absorption and emission spectra, electrochemical techniques, and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic interaction with intrinsic binding constant of 2.67 × 10⁴ (mol L^?1)^?1. The influence of anions on the structure and the interaction of the binuclear complex with HS-DNA were preliminarily discussed.     

Crystal structure of [{Cu(H2O)(en)2}{Cu(en)2}Re6Te8(CN)6]·3H2O

The reaction of Cs₄[Re₆Te₈(CN)₆]·2H₂O with Cu(en)₂Cl₂ in water affords crystals of a cluster complex [{Cu(H₂O)(en)₂}{Cu(en)₂}Re₆Te₈(CN)₆]·3H₂O. The structure of the compound is determined by single crystal X-ray diffraction (a = 10.8082(4) Å, b = 16.5404(6) Å, c = 24.6480(7) Å, β = 92.696(1)°, V = 4401.5(3) ų, Z = 4, space group P2₁/n, R ₁ = 0.0331, wR ₂ (all data) = 0.0652). In the complex, cluster [Re₆Te₈(CN)₆]^4? anions are linked by Cu²⁺ cations into zigzag chains through cyanide bridges. The coordination environment of the copper cations is complemented by ethylenediamine molecules. Each of the cluster anions is additionally coordinated by a terminal fragment {Cu(H₂O)(en)₂}.     

掺杂对超导体(Tl1-x-yPbxMy)Sr2(Ca0.8Ln0.2)Cu2O7-δ(M=Sn4+或Sb5+, Ln=Y,La, Nd或Pr)性能的影响

Subramanian et al. found superconductivity at 80 K in Tl_(0.5)Pb_(0.5)Sr_2CaCu_2O_y sample with YBa_2 Cu_3 O_(7-δ)-like structure. However, there is unstable factor in the structure of the superconductor. Total plus valence is 12.5, and total minus valence is 14. The structure was further stabilized by partial substitution of Y, La, Nd orPr for Ca and Sn~(4+) or Sb~(5+) for (Tl, Pb), so that T_c was achieved above 100 K. For example, T_c is about 103 K in a sample with nominal composition (Tl_(0.4) Pb_(0.5)Sn_(0.2))Sr_2(Ca_(0.8)Y_(0.2))Cu_2O_(7-δ). During the preparation of superconductors, the temperature of samples was very slowly down after sintering, or samples were annealed at 500—700 ℃. The samples absorbed the oxygen during cooling, but no phase change occured. Appropriate amount of the oxygen made T_e higher.     

Ab initio electron correlated studies on the intracluster reaction of NO+ (H2O)(n) → H3O+ (H2O)(n-2) (HONO) (n = 4 and 5)

Hydrated nitrosonium ion clusters NO(+)(H(2)O)(n) (n = 4 and 5) were investigated by using MP2/aug-cc-pVTZ level of theory to clarify isomeric reaction pathways for formation of HONO and fully hydrated hydride ions. We found some new isomers and transition state structures in each hydration number, whose lowest activation energies of the intracluster reactions were found to be 4.1 and 3.4 kcal mol(-1) for n = 4 and n = 5, respectively. These thermodynamic properties and full quantum mechanical molecular dynamics simulation suggest that product isomers with HONO and fully hydrated hydride ions can be obtained at n = 4 and n = 5 in terms of excess hydration binding energies which can overcome these activation barriers.     

Synthesis and Characterization of Nitrato-Triamine-Metal(II) Complexes. Conglomerate Crystallization Part 55. Crystal Structure of [Ni(dien)(O2NO)(ONO2)] (I), {[Cu(dien)-(μ-ONO2)]NO3}∞ (II), [Zn(dien)(O2NO)(ONO2)] (III), [Ni(Medpt)(O2NO)(ONO2)] (IV) and [Cu(Medpt)(ONO2)2] (V)

In absolute ethanol and in the presence of triethylorthoformate, reactions of metal(II) nitrates with linear tridentate amines afforded metal complexes of the formula M(NNN)(NO₃)₂, where M = Ni²⁺, Cu²⁺ and Zn²⁺, and NNN = dien and Medpt. The compounds fall into three categories in accordance with their stereochemistry and mode of binding of the nitrato ligands. Compounds I, [Ni(dien)(O₂NO)(ONO₂)] and III, [Zn(dien)(O₂NO)(ONO₂)] are isomorphous and isostructural. They crystallize in the monoclinic space group P2₁/n with nearly identical cell constants. The stereochemistry of these two compounds is such that the terdentate dien ligand forms a fac MN₃ moiety with the two oxygens of the bidentate nitrato ligand trans to the terminal NH₂. These ligands form the base of the octahedral arrangement in which the sixth position, trans to the secondary nitrogen of the dien, is an oxygen of the monodentate nitrato ligand. Compound IV, [Ni(Medpt)(O₂NO)(ONO₂)] falls into the same category as I and III despite the fact that the two rings in the Ni-Medpt moiety are six-membered rings, unlike those in compounds I and III which are five-membered rings. Nevertheless, the nickel-amine arrangement is fac. The bidentate nitrato-oxygens are trans to the terminal NH₂ of the amine ligand, and the oxygen of the monodentate nitrato ligand is trans to the tertiary amine-nitrogen. Such stereochemistry is prevalent for nickel and zinc compounds. Interestingly, compound IV crystallizes as a conglomerate (space group P2₁2₁2₁). Compound II, {[Cu(dien)(μ-ONO₂)]NO₃}_∞ belongs to the second category and has a polymeric structure. The repeating fragment in the polymeric chain is a Cu(dien)-O fragment with the monodentate nitrato ligand occupying an equatorial position of the base. A second oxygen of the equatorial nitrate becomes an axial ligand for an adjacent Cu-N₃O fragment. In this way the substance propagates into an infinite chain. The repeating unit has an effective square pyramidal, five-coordinate, configuration. Finally, the compound crystallizes as a racemate. The second nitrate necessary for charge compensation of this copper(II) compound is ionic and its function is to hold the infinite chains of the lattice. The third category represented by compound V, [Cu(Medpt)(ONO₂)₂] contains two molecules in the asymmetric unit of the racemic lattice (monoclinic, space group P2₁/a). The structure of Cu-Medpt is unlike that of IV in that both species present in the asymmetric unit have the amine ligand in a mer configuration which together with a monodentate oxygen of a nitrato ligand form a base plane of a square pyramid. The fifth ligand of both Cu²⁺ ions is a second monodentate nitrato ligand. The stereochemical differences between the two Cu²⁺ ions are insignificant for the Cu-Medpt fragment, which share the same conformation and configuration. The major difference between the two species is the torsional angles defined by the Cu-O-N-O angles. The difference arises from variation in the hydrogens of the primary amine moieties selected by nitrato-oxygens to form intramolecular hydrogen bonds. Finally, there is a little variation in the equatorial Cu-ONO₂ stereochemistry because of steric hindrance, imposed by the Medpt, preventing large torsional angles by these nitrato ligands. This is evident by comparing the two copper species shown in Finally, nitrate-to-Br ligand exchange was found to take place when KBr pellets are prepared for IR spectral measurements.     

Synthesis and Structure of a Novel Compound [Cu2(EDTA)(Py)2(H2O)2]·2H2O

A novel compound [Cu2(EDTA)(Py)2(H2O)2]·2H2O was synthesized by the reaction of CuSO4(5H2O with H4EDTA in pyridine/water (V/V = 1/4) solvent, and characterized by elemental analysis, IR spectrum and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 1.26974(6), b = 0.67949(3), c = 1.48548(3) nm, β = 91.454(2)o, V = 1.28122(9) nm3, Z = 2, Dc = 1.673 g/cm3, Mr = 645.56, F(000) = 664, μ(MoKα) = 1.729 mm-1, the final R = 0.0353 and wR = 0.0832 for 1920 observed reflections (I > 2((I)). The compound is a centrosymmetric binuclear molecule with bridged EDTA group. Each Cu(II) atom is linked to two oxygen atoms and one nitrogen atom of EDTA, one oxygen atom of water and one nitrogen atom of pyridine to form a distorted square pyramidal environment. There exist face-to-face π-π stacking interactions between pyridine rings from neighboring molecule with the interplanar distance of 0.3670 nm and hydrogen bonding between EDTA and water molecules.     

配合物Cu(pico)(4,4′-bipy)(H2O)ClO4·H2O的合成及其晶体结构

利用水热法合成了新型一维配合物Cu(pico)(4,4′-bipy)(H2O)ClO4·H2O(1,bipy=联吡啶,pico=邻吡啶甲酸根),其结构经IR,元素分析和X-射线单晶衍射表征.1属于单斜晶系,P21/n空间群,晶胞参数:a=0.853 57(8)nm,b=1.610 58(14)nm,c=1.416 85(13)nm,β=99.407(2)°,V=1.921 6(3)nm3,Z=4,Mr=477.31 g·mol-1,Dc=1.650 g·cm-3,μ=1.326mm-1,F(000)=972,R1=0.078 1,wR2=0.239 1,S=1.102.1中Cu2 与邻吡啶甲酸配体上一个N原子和一个O原子、两个4,4′-联吡啶的N原子以及一个水分子的O原子配位,形成了四方锥配位几何构型.在a c轴方向,Cu2 与两个4,4′-联吡啶分子经桥联作用形成一维zig-zag链;链与链通过氢键形成三维结构.