PREPARATION AND ADSORPTION OF THIOUREA MODIFIED GLUTARALDEHYDE-CROSSLINKED CHITOSAN RESINS

The preparation and adsorption of thiourea modified glutaraldehyde-crosslinked chitosan resin (Thio-chitosan) using cyanuric chloride as activator was studied. The adsorptive capacity of thio-chitosan with 15% apparent degree of crosslinking (DC, mass ration of glutaraldehyde to chitosan) to Cu(Ⅱ) was 160mg/g (dry weight). The adsorption of Cu(Ⅱ) was correlated with Freundlich and Langmuir isotherm equation. Cu(Ⅱ) adsorbed on thio-chitosan column ( 1 cm×10 cm)was eluted with 0.5mol/L H2SO4, 6mol/L HCl and 3% thiourea solution with the recovery of 88.3%,86.1% and 95.3%, respectively. The thio-chitosan resin can be applied to the separation and recovery of metal ions.     

Indirect determination of cefradine with n-propyl alcohol-ammonium sulfate-water system by extraction-flotation of cuprous thiocyanate

A new method was developed for the determination of cefradine by extraction-flotation of CuSCN.The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100℃.The thiol group(-SH)of the degradation product could reduce Cu(Ⅱ)to Cu(Ⅰ)for the formation of the emulsion CuSCN in the presence of NH_4SCN at pH 4.0.By determining the residual amount of Cu(Ⅱ)in the solution and calculating the flotation yield of Cu(Ⅱ),the indirect determination of cefradine can be obtained.This method has been applied to determine cefradine in capsules,human serum and urine samples,respectively.     

Trihydrated Complex of Tetrabenzimidazole Copper(Ⅱ) Sulfate

A Trihydrated complex of benzimidazole copper(Ⅱ) sulfate [(C7H6N2)4CuSO4]·3H2O was synthesized and structurally characterized. The crystal structure of this compound is built up of six solvated water molecules and two dissimilar copper ions identified as Cu1 and Cu2. The coordination geometry of copper(Ⅱ) is a slightly distorted square pyramid. The four equivalent tertiary nitrogen atoms of the benzimidazole ligand form an equatorial plane, while the oxygen atoms of sulfato occupy the axial site. In the solid state, the title compound forms a three dimensional network structure via hydrogen bonds. The benzimidazole, sulfato ion and H2O moieties are connected by the intermolecular hydrogen bonds. The (EPR) spectrum shows axial symmetry with g⊥=2.039 and g∥=2.285. Variable temperature magnetic susceptibility shows that there is a weak antiferromagnetic interaction between the neighboring copper(Ⅱ) ions.     

Two Novel Copper(Ⅱ) Complexes with A Novel Ligand 2,4-Di(2-aminopyridine)-6-methylpyrimidine

Introduction The design and syntheses of multidentate N-donor ligands have become the focus of much inter-est in the chemical field[1-4]because these ligands can form multinuclear metalxompounds, coordina-tion polymers and supramolecular compounds,which play a very important role in the bilolgicalsystems, magnetic materials,electric materials,optical materials and otherfields[5-8].     

One-dimensional Copper(Ⅱ) Complex Constructed with Nitrate Counter-anion as Bitopic Connector

Coordination polymer {[Cu(NPPCA)3(NO3)(H2O)]·NO3·H2O}n 1 ( NPPCA = N-(4′-nitrophenyl)-4-pyridinecarboxamide) has been synthesized by the reaction of NPPCA with copper(Ⅱ) nitrate in ethanol-water solution and characterized by X-ray diffraction. 1 crystallizes in the monoclinic space, group P21/n, a = 17.341(6)A, b = 6.744(2) (A), c = 34.555(12)(A), β =100.493(6)°, V = 3974(2) (A)3, Z = 4. Each copper(Ⅱ) ion has a distorted octahedral coordination geometry. Nitrate anion adopts the unusual coordination mode linking two adjacent copper(Ⅱ)ions to form a one-dimensional coordination polymer and these chains are further linked by noncovalent interactions.     

Synthesis,Characterization,and DNA Binding Properties of Dinuclear Copper(Ⅱ)Complex [Cu2(TATP)2(L-Leu)2(CIO4)2]2°2H2O

A dinuclear copper(Ⅱ) complex [Cu2(TATP)2(L-Leu)2(ClO4)2]2.2H2O was synthesized and characterized,where,TATP=1,4,8,9-tetraazatriphenylene,and L-Leu=L-leucinate,The complex was crystallized in the triclinic space group P1,with two independent molecules in a unit cell,Two Cu(Ⅱ) ions in each complex[Cu2(TATP)2(L-Leu)2(ClO4)2]molecule were found to be in different coordination geometries,i.e.,Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP,the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate,and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms,and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4,The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.     

Synthesis and Catalytic Activity of Copper(Ⅱ) Resorcylic Acid Nanoparticles

Copper(Ⅱ) resorcylic acid(CuRes) nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained was characterized by using X-ray diffraction( XRD), transmission electron microscopy( TEM ), Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analyses (TG), and element analysis. In addition, the catalytic activity of CuRes nanoparticles on the thermal decomposition of nitrocellulose-nitroglycerine (NC-NG) was also determined via DSC.The results show that the spherical nanoparticles with a diameter of 20 nm were obtained in ethanol solution. The peak temperature of the thermal decomposition of NC-NG-CuRes decreases by 3 ℃ compared with that of normal CuRes,and the decomposition enthalpy is increased by 735 J/g, and therefore, it is reasonable to assume that CuRes nanoparticles have a better catalytic activity.     

Synthesis and Crystal Structures of the α and β Forms of Bis(salicylaldoxime)copper(Ⅱ) Complexes

Modified α and β bis(salicylaldoxime)copper(Ⅱ) have been obtained by recrystallization from ethyl acetate(CCDC Nos. 212157 & 212158). The X-ray analysis reveals that the two modificated forms have the same structure with different geometric parameters. The α form crystallizes in the P2(1)/c space group and the β form in the P1 space group. Both the crystal structures consist of centrosymmetric monomeric molecules of Cu(OC6H4CNOH)2. The IR spectra are in agreement with the structural data.     

A novel spectrophotometric determination of copper(Ⅱ) with bromosulphonazo Ⅲ

A novel ehromogenic reaction involving copper(Ⅱ) and bromosulphonazo Ⅲ (Br-SAZⅢ) in hexamethylenetetramine-hydrochloric buffer solution was investigated. The results showed that a blue complex of copper(Ⅱ) and bromosulphonazo Ⅲwas formed with a molar ratio of 1:1. The apparent molar absorptivity was 3.3 × 105Lmol-1cm-1 and themaximum absorption peak was at 616.8 nm. The proposed procedure was used for quantitative estimation of Cu(Ⅱ) inthe concentration range of 0-1.024 μg/mL with the detection limit (3σ) of 7.03 × 10-4 μg/mL (n = 20). The relativestandard deviations (RSDs) were 0.56-4,68%. Under the optimized conditions, total copper in the vegetables and tea wassuccessfully determined.     

Synthesis and Properties of u-Oxamido Heterobinuclear Cu(Ⅱ)-Co(Ⅱ) Complexes

Three heterobinuclear complexes were synthesized, namely [Cu (oxpn) Co (L)2] (ClO4)2·xH2O(L= 2,2'-bipyridyl(bpy), 1,10-phenanthroline(phen) , and 5-nitro-1, 10-phenanthroline (NO2-phen)), where oxpn represents N, N'-bis(3-aminopropyl) oxam-ido. Based on 1R, elemental analysis, conductivity measurement and electronic spectra, these complexes were characterized by an extended oxamido-bridged structure with Cu(Ⅱ) in a planar environment and Co(Ⅱ) in a octahedral environment. The symmetry of the cation is very close to C2v.The complexes were also characterized with variable temperature (4~300K) magnetic susceptibility, and the data were fit for the susceptibility equation derived from spin Hamilton, H= -2JS1.S2-DSx12 by least square strategy. The exchange integral, J, was found to be -22.36 cm-1 (for bpy);-15.45 cm-1 (for phen); -19. 10cm-1(for NO2-phen), indicating that there is a weak antiferromagnetic spin-exchange interaction between the metal ions.     

Simple,Selective,and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel(Ⅱ),Copper(Ⅱ), Cobalt(Ⅱ),and Iron(Ⅲ)with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone(2-PYAINH)was synthesized and studied for the spectrophotometric determination of nickel,copper,cobalt,and iron in detail.At a pH value of 7.0,9.0,9.0,and 8.0,respectively,which greatly increased the selectivity;nickel,copper,cobalt, and iron reacted with 2-PYAINH to form a 1:2 yellow-orange,1:2 yellow-green,1:2 yellow and 1:1 yellow complexes,with absorption peaks at 363,352,346,and 359 nm,respectively.Under the optimal conditions,Beer's law was obeyed over the ranges of 0.01-1.4,0.01-1.5,0.01-2.7,and 0.01-5.4 mg/L,respectively.The apparent molar absorptivity and Sandell's sensitivities were 8.4×104,5.2x104,7.1×104,and 3.9×104L·mol-1.cm-1,respectively,and 0.00069,0.0012,0.00078,and 0.0014 μ g·cm-2,respectively.The detection limits were found to be 0.001,O.002,0.003,and 0.01 mg/L,respectively.The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.     

Synthesis and Magnetism of 2-Hydroxy-1,3-propylene-bis(oxamato)-bridged Co~ⅡCu~ⅡCo~Ⅱ Complexes

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Synthesis and properties of the copper(Ⅱ) complexes with stable radical

Four novel copper(Ⅱ) complexes have been synthesized,namely Cu(hfac)2NITPhNO2 (1),Cu(hfac)2NITPhCH3 (2),Cu(pfpr)2NITPhNO2,(3) and Cu(Pfpr)2NITPhCH3 (4),where hfac= hexafluoro-acetylacetonate,pfpr=pentafluoropropionate,NITR.=2-R-4,4,5,5-tetraniethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide.(R=4-nitrophenyl,4-methylphenyl).These complexes were rharicter-ized by elemental analyses,IR,electronic spectra and molar conductance.The temperature-dependent magnetic susceptibility of complexes 1 and 3 have been studied in the 4 300 K range,giving I he exchange integral J=10.56 cm-1 for complex 1 and J =-30.9 cm-1 for complex 3.     

DNA Cleavage by Copper (Ⅱ) Complexes Without added Coreactants

Thedevelopmentofreagentswhichhydrolyticallycleave11ucleicacids"lidermildconditionsiscurrentlyattractinggreatinterestillthetieldofartiticialnucleases'-'.Whilemall}lreagentshavebeedsuccessfullyapplied.toDNAhydrolysis;.illershavebeenit-c'l'ersuccesseswithDNA'duetoitsrelativel}'highh}idrolyticstabilit}"(thepseudo-firsl-orderrateconstantt'Orthenollenzymatichydrolysisofphospllodiestersisextropolatedtobe2x10-"'h-=at24tandPH7.4').Theexceptionalstabilit}fofphosphodiestershasbeensuggestedasonereason…     

Studies of copper (Ⅱ) complexes as catalysts for the hydrolysis of DNA

Hydrolysis of DNA is an important enzymatic reaction , but it is exceedingly difficult to mimic in the laboratory because of the stability of hydrolysis of DNA. In this paper, the cleavage activity of complexes formed between Cu(Ⅱ) and four different amino acid or amino acid methyl ester on DNA is studied by gel elec-trophoresis. It is found that DNA could be cleaved by Cu(Ⅱ)-L-His and Cu(Ⅱ)-L-His methyl ester complexes and the efficiency of cleavage is largely dependent on the metal ion-to-ligand ratio. Further experiments show that the cleavage of DNA mediated by Cu(Ⅱ)-L-His complexes occurs via a hydrolytic mechanism and the active chemical species that affects DNA cleavage is proposed to be MI2H and ML2H22 .     

Synthesis and Conductivity of a One-dimensional Polymer of a Copper(Ⅱ)-porphyrazine with Sulfur Bridges

Phthalocyanines(Pcs)andtheirpolyinershavebeenasubjectofgreatinterestduetotheirhighthermalstabilityanduniquephotoelectricpropertiesl4.Ithasbeenfoundthatsomeelectronicfunctionsofthemetalthioporphyrazinesandtheirconjugatedpolymers,suchasgas-sensitivityphotosensitivity,photoconductivityandelectrocatalyticactivity,aremorepeculiarthancorrespondingPcs5'6.Oneofourinterestsistodesignanovelpolymerofmetalporphyrazines(PMPzs)withswitchingpointsunderthecontrolofachangingexternalfieIdorenvironment.Inthepr…     

Synthesis,characterization and magnetism of copper(Ⅱ)-lan-thanide(Ⅲ) heterobimetalic complexes with N,N'-oxamidobis-(benzoato) cuprate (Ⅱ)

Seven new μ-oxamido copper(Ⅱ)-lanthanide(Ⅲ)hetero-bitnetalic complexes described by the fonnula Cu(obbz)Ln-(Ph-phen)2NO3(Ln=La,Nd,Eu,Gd,Tb,Ho,Er),where obbz denotes the oxamidobis(benzoato)and Ph-phen represents 5-phenyl-1,10-phenanthroline,have been synthesized and characterized by the elemental analyses,spectro-scopic(IR,UV,ESR)studies,magnetic moments(at room temperature)and molar conductivity measurement.The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph-phen)2NO3 complex has been measured over the range 4.2-300 K.The least-squares fit of the experimental susceptibilities based on the spin Hamiltonian operator,H=-2JS1 S2,yielded J= 1.28 cm-1,a weak ferromagnetic coupling.A plausible mechanism for a ferromagnetic coupling between Gd(Ⅲ)-Cu(Ⅱ)is discussed in terms of spin-polarization.     

Cu(OTf)_2-catalyzed ring-opening of epoxides with anilines:A convenient synthesis of β-amino alcohols

The regioselective ring-opening of epoxides with aniline and p-chlorop niline catalyzed by copper(Ⅱ) triflate provides the corresponding β-amino alcohols in excellent yields.     

Synthesis and Magnetic Properties of Copper (Ⅱ) Complexes with Pyridine N-Oxide-2-ylmethy-lidenedithiocarbazate as Ligands

A series of copper (Ⅱ) complexes with pyridine N- oxide- 2- ylmethylidened-ithiocarbazates as ligands were synthesized and characterized by IR spectra, electronic spectra and magnetic moments measurement at room temperature. Variable temperature magnetic susceptibilites (3-300K) of four complexs were measured and fitted with the Bleaney-Bowers dimer equation by considering the magnetic interaction between molecules. The fitting results show the existence of intramolecular ferromagnetic interactions and intermolecu-lar anti-ferromagnetic interactions in these copper( Ⅱ) complexes.     

L-苏氨酸铜(Ⅱ)超分子配合物的合成、晶体结构及性质

合成了L-苏氨酸铜(Ⅱ)超分子配合物[Cu(C4H8NO3)2].H2O,通过元素分析、红外、差热-热重、紫外光谱和单晶结构对其结构进行确认。该化合物由1个Cu(Ⅱ)离子、2个L-苏氨酸阴离子和1分子结晶水组成,其中氨基酸的羧基氧原子及氨基氮原子与铜(Ⅱ)离子配位,形成六配位拉长八面体构型,单胞之间通过分子间氢键构成三维网状超分子体系。配合物在水溶液中的紫外吸收波长为233nm,固态荧光发射之间通过分子间氢键构成三维网状超分子体系。配合物在水溶液中的紫外吸收波长为233nm,固态荧光发射出现在357nm。电化学行为显示,配合物在玻碳电极上为不可逆的氧化还原过程,反应过程受扩散控制。