Operando HERFD-XANES and surface sensitive Δμ analyses identify the structural evolution of copper(Ⅱ) phthalocyanine for electroreduction of CO_(2)

The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.

Sorption Kinetic Analysis for the Removal of Copper(Ⅱ) by Using Biofilm

The biosorption of copper(Ⅱ) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(Ⅱ) sorption capacity under the conditions of room temperature, initial pH value of 6.0 and the sorbent mass 8 g. The experimental data were analyzed using four sorption kinetic models, the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations to determine the best-fit equation for the sorption of metal ions onto biofilm. Comparing with the sum of squared-errors, the results show that both the Ritchie second order and modified second order equations can fit the experimental data very well.

Fixed-bed column study for deep removal of copper(Ⅱ) from simulated cobalt electrolyte using polystyrene-supported 2-aminomethylpyridine chelating resin

This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height (7.0–14.0 cm),feed flow rate (4.5–9.0 mL/min),initial copper (Ⅱ) concentration of the feed (250–1000 mg/L),feed temperature (25–40 ℃) and the value of pH (2.0–4.0) on the adsorption process of the PS-AMP resin were investigated.The experimental data showed that the PS-AMP resin can deeply eliminate copper (Ⅱ) from the simulated cobalt electrolyte.The bed height,feed flow rate,initial copper (Ⅱ) concentration of the feed,feed temperature and feed pH value which corresponded to the highest removal of copper (Ⅱ) were 7.0 cm with 35 mm of the column diameter,4.5 mL/min,40℃,1000 mg/L and 4.0,respectively.The breakthrough capacity,the saturated capacity of the column and the mass ratio of Cu/Co (g/g) in the saturated resin were correspondingly 16.51 mg/g dry resin,61.72 mg/g dry resin and 37.67 under the optimal experimental conditions.The copper (Ⅱ) breakthrough curves were fitted by the empirical models of Thomas,Yoon-Nelson and Adam-Bohart,respectively.The Thomas model was found to be the most suitable one for predicting how the concentration of copper (Ⅱ) in the effluent changes with the adsorption time.

Crystal Structure, Electrochemical and Fluorescent Properties of a New Copper(Ⅱ) Coordination Polymer with 2,3-Pyridinedi-carboxylic Acid

A new copper(Ⅱ)coordination polymer[Cu5(Hpt)5(H2O)2(2,3-PCA)2]n·12nH2O(1)has been successfully synthesized under hydrothermal conditions with copper hydroxide,3-(pyridin-2-yl)-1,2,4-triazole(Hpt)and 2,3-pyridinedi-carboxylic acid(2,3-PCA).The structure of the title compound was determined by X-ray diffraction analyses,elemental analyses and IR spectrum.The architecture of 1 consists of one-dimensional sandwich-like chains which are connected by extensive hydrogen bonding interactions.The solid-state photoluminescence displays an obvious emission band at 384 nm upon excitation at 340 nm.In addition,electrochemistry property has also been studied.

Determination of Ultratrace Amounts of Copper(Ⅱ) in Water Samples by Electrothermal Atomic Absorption Spectrometry After Cloud Point Extraction

A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyridylazo ） -2- naphthol was used as the chelating reagent and Triton X-114 as the mieellar-forming surfactant. CPE was conducted in a pH 8. 0 medium at 40 ℃ for 10 rain. After the separation of the phases by contrifugafion, the surfactant-rieh phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20μL of the diluted surfactant-rieh phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconeentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0 ng/mL, and the relative standard deviation was found to be less than 3. 1% for a sample containing 1.0 ng/mL Cu （ Ⅱ ）. This developed method was successfully applied to the determination of uhratraee amounts of Cu in drinking water, tap water, and seawater samples.

Thermal Behavior, Non-isothermal Decomposition Reaction Kinetics of Copper(Ⅱ) Salt of 4-Hydroxy-3,5-dinitropyridine and Its Application in Propellant

The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.

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

Copper（ Ⅱ ） resercyiic 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 micrescopy（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.

Hydrothermal Synthesis,Crystal Structure and Thermal Stability of a Binuclear Copper(Ⅱ) Complex with 3-(Pyridin-2-yl)-1,2,4-triazole

One novel binuclear copper（Ⅱ） complex [Cu 2 （Hpt） 2 （CO 3） 2 （H 2 O） 2 ]·H 2 O with copper carbonate and 3-（pyridin-2-yl）-1,2,4-triazole （Hpt） was hydrothermally synthesized and characterized by IR and X-ray diffraction analysis.The complex crystallizes in triclinic,space group P2 1 /n with a=0.6862（1）,b=0.7805（1）,c=1.1983（2） nm,α=72.03（2）,β=107.72（3）,γ=75.28（2）o,V=0.5884 nm 3,D c=2.105 g/cm 3,Z=1,F（000）=357,GOOF=1.041,the final R=0.01859 and wR=0.04348.The whole molecule is composed of two cooper ions,two Hpt molecules,two carbonate and three water molecules,forming a binuclear structure.The crystal structure shows that the cooper ion is coordinated with three nitrogen atoms from two Hpt molecules,two oxygen atoms from one carbonic acid and one water molecule,forming a distorted square pyramidal geometry.The TG analysis result shows that the title complex is stable under 131.0 ℃.

A novel spectrophotometric determination of copper(Ⅱ) with bromosulphonazoⅢ

A novel chromogenic 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 Ⅲ was formed with a molar ratio of 1：1. The apparent molar absorptivity was 3.3×10^5Lmol-1cm-1 and the maximum absorption peak was at 616.8 nm. The proposed procedure was used for quantitative estimation of Cu（II） in the concentration range of 0-1.024μg/mL with the detection limit （3σ） of 7.03 × 10^-4 μg/mL （n = 20）. The relative standard deviations （RSDs） were 0.56-4.68%. Under the optimized conditions, total copper in the vegetables and tea was successfully determined. 2007 Li Yuan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Synthesis,Structure and Magnetic Properties of Novel Carboxylato-bridged Pentanuclear Copper(Ⅱ)-Lanthanoid(Ⅲ)Complexes

Six novel pentanuclear complexes [Cu 3Ln 2(ClCH 2CO 2) 12 (H 2O) 8]·2H 2O (Ln=La, Pr, Sm, Gd, Dy, or Er) were synthesized by the reaction of chloroacetic acid with Cu and Ln ions in aqueous solutions. The X ray crystallography established the structure of the Gd complex, which contains a pair of quadruply acetato bridged CuGd dinuclear subunits, and each of them is linked to the central Cu atom by a single acetato bridge. The coordination sphere of each Gd atom is completed by three aqua ligands [Gd-O=0.242 8(5)-0.244 4(4) nm] to form an 8 coordinated distorted square antiprism. The central Cu atom is coordinated by two oxygen atoms from the two bridging acetato groups and two oxygen atoms from the two monodentate acetato groups in a slightly distorted square planar fashion, while each terminal Cu atom is coordinated by the four acetato oxygen atoms at the basal plane and an aqua ligand at the apical position to form a square pyramid. The variable temperature (4 320 K) magnetic susceptibility data of the Gd complex were measured, and fitted to the Curie Weiss law with C =16.38 K cm 3·mol -1 and θ =-1.55 K, indicating very weak antiferromagnetic interaction.

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(OC_6H_4CNOH)_2. The IR spectra are in agreement with the structural data.

Synthesis and Crystal Structure of 1-D Chain Copper(Ⅱ) Complex: [Cu(L)Cl_2]_n (L=2,5-Di-2-pyridyl-1,3,4-oxodiazole)

The title complex, [Cu(L)Cl2]n (L = 2,5-di-2-pyridyl-1,3,4-oxodiazole) 1, has been obtained from the reaction of 3,6-di-2-pyridyl-1,2,4,5-tetrazine (bptz) and CuCl2?H2O in a mixture solvent of CH3CN and CH2Cl2 (L is generated from the metal-assisted hydrolysis reaction of bptz) and structurally characterized. It crystallizes in space group C2/c of monoclinic system with cell parameters: a = 9.812(2), b = 12.679(3), c = 11.111(2) ? b = 103.92(3)? V = 1341.6(5) 3, Z = 4, Dc = 1.776 g/cm3, Mr = 358.66, F(000) = 716, ?= 2.024 mm1 and S = 1.004. The final R = 0.0346 and wR = 0.0938 for 1011 observed reflections with I > 2(I). The Cu(Ⅱ) ion is six-coordinated by four N atoms of two L ligands and two Cl ions in a distorted octahedral geometry. The ligand L acts as a bis-bidentate ligand to bridge the Cu(Ⅱ) ions, resulting in an infinite chain structure.

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

A novel conjugated polymer which shows sendconductivity at T < 260K and T >286K and metallic conductivity at 260K < T< 286K was syllthesized by reaction of 2, 3, 5, 6-tetracyano1, 4-dithiin and phthalonitrile with CuCl2.2H2O.

Synthesis and Crystal Structure of Copper(Ⅱ) Compound with Didentate Schiff-base Ligand

The title complex [Cu(L)2] (HL=4-salicylideneamino-3,5-dimethanol-1,2,4-triazole) was synthesized by the reaction of Cu(CH3COO)22H2O with 4-salicylideneamino-3,5-dimethanol- 1,2,4-triazole in the methanol. The single-crystal X-ray study reveals that the compound crystallizes in monoclinic, space group P21/n with a = 11.746(5), b = 8.145(3), c = 12.786(5) ? b = 106.64(1), V = 1172(1) ?, Z = 2, Dc = 1.581 g/cm3, m = 0.989 mm-1, F(000) = 574, C22H22Cu- N8O6, Mr = 558.02, T = 293(2) K, R = 0.0394 and Rw = 0.0835 for 2376 observed reflections with I > 2s(I). The complex comprises a four-coordinated copper(II) center, with an N2O2 planar coordi- nation environment. The molecules are connected by hydrogen bonds to form one-dimensional chains which are further linked to form a two-dimensional plane.

Hydrothermal Synthesis and Crystal Structure of a Novel Hexanuclear Copper(Ⅱ) Complex:[Cu_6(DPPZ)_4(btc)_4(H_2O)_8]·5H_2O

A new hexanuclear copper（Ⅱ） complex,[Cu 6 （DPPZ） 4 （btc） 4 （H 2 O） 8 ]·5H 2 O （1,DPPZ=dipyrido[3,2-a：2,3-c]phenazine,H 3 btc=1,3,5-benzenetricarboxylic acid）,has been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction,elemental analyses,IR,and thermogravimetric analysis.Its crystal structure is of triclinic system,space group P1 with a=12.489（4）,b=14.234（5）,c=14.484（5）,α=82.848（4）,β=79.399（4）,γ=73.646（4）°,V=2421.2（13） 3,Z=1,Cu 6 C 108 H 78 N 16 O 37,M r=2573.17,D c=1.752 g/cm 3,μ=1.398 mm-1,F（000）=1308,GOOF=1.011,the final R=0.0495 and wR=0.1030 for 5420 observed reflections with I 2σ（Ⅰ）.In 1,four btc 3ligands act as bridges between six neighboring Cu atoms to form an unusual hexanuclear copper cluster.The clusters are further connected by two types of O-H···O and O-H···N hydrogen bonds,generating a three-dimensional supramolecular structure.In addition,intermolecular and intramolecular π-π stacking interactions further consolidate the three-dimensional supramolecular framework of 1.

Synthesis,Crystal Structure and Thermal Stability Properties of a Binuclear Copper(Ⅱ) Coordination Polymer {[Cu_2(4,4'-bipy)_2(o-ABA)_4(H_2O)_2][(H_2O)_2]}_n

One-dimensional chain copper（Ⅱ） coordination polymer has been synthesized and characterized in the solvent mixture of water and alcohol with o-acetamidobenzoic acid,4,4＇-bipyridine and copper perchlorate.It is of tetragonal,space group P41212 with a=1.57756（10）,b= 1.57756（10）,c=2.1438（3）nm,V=5.3352（8） nm^3,Dc=1.524 g/cm^3,Z=4,F（000）=2536,R= 0.0479 and wR=0.0979.The crystal structure shows two coordination modes.The copper（1） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule and two oxygen atoms from two o-acetamidobenzoic acid molecules,forming a distorted tetrahedral coordination geometry; the copper（2） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule,four oxygen atoms from two o-acetamidobenzoic acid molecules and two water molecules,generating a distorted octahedral coordination geometry.The result of TG analysis shows that the title complex is stable below 180.0 ℃.

Synthesis and Crystal Structure of Bis[O,O'-di(2-phenylethyl)dithiophosphato](α,α'-bipyridine)copper(Ⅱ)

A ternary adduct Cu[S2P（OCH2CH2Ph）2]2·bipy（bipy=α,α＇-bipyridine） was syn-thesized and characterized by elemental analysis,IR and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P1 with a=10.2320（2）,b=11.5249（3）,c=18.0916（3）,α=98.95（1）,β =103.601（1）,γ=91.272（2）°,V=2044.49（7）3,Z=2,Dc=1.453 g/cm3,T=153（2） K,C42H44CuN2O4P2S4,Mr=894.51,λ（MoKα）=0.71073,μ=0.86 mm-1,S=0.999,（△/σ）max=0.002,the final R=0.0243 and wR=0.0704.A total of 9221 unique reflections were collected,of which 8573 with Ⅰ 〉2σ（Ⅰ） were observed.The Cu（Ⅱ） atom is five-coordinated in a rather distorted trigonal bipyramidal geometry（τ value=0.537）.The Cu-S distances range from 2.3491（4） to 2.4829（4） ,and the Cu-N distances are 1.9987（12） and 2.0584（11） ,respectively.An interesting feature of this adduct resides in its two-dimensional（2D） open framework constructing through hydrogen bonding and π-π interactions.

A Novel Copper(Ⅱ) Complex of Asymmetrically N-Functionalized 1,4,7-Triazacyclononane Ligand： Syntheses, Structure, Electrochemical Property and Biological Activities

A novel copper（Ⅱ） complex derived from 1,4,7-triazacyclononane[CuL]_2（PF_6）_3×MeCN×H_2 O was synthesized and crystallographically characterized {L = 1,4-bis（2-carbamoylethyl）-7-benzimidazole-2-yl-methyl-1,4,7-triazacyclononane}. It crystallizes in triclinic, space group P1, with a = 13.2425（13）, b = 14.0807（15）, c = 17.6798（18）, α = 86.296（2）, β = 72.773（2）, γ= 68.905（2）o, V = 2934.5（5）A^3, Z = 2, D_c = 1.611 g/m^3, F（000） = 1456, M_r = 1423.09, m = 0.920 mm^-1. The final R = 0.0671 and wR = 0.1874 for 6501 observed reflections with I 〉 2σ（I）. The structural analysis shows that the complex cation（[CuL]_2^3＋） was formed by two complex cations, namely（[CuL^3]^2＋） and [CuL_（-H）~3]~＋） through a hydrogen bond. In each complex cation, the Cu（Ⅱ） lies in a distorted square pyramidal geometry. The redox behavior was studied by cyclic voltammetry（CV） in aqueous solution which indicates a reversible one electron redox reaction. The result of UV absorption, ethidium bromide（EB） fluorescence spectra indicated that the complex binds to CT-DNA in an intercalative mode. Superoxide dismutase（SOD） activity of the complex was determined by photoreduction of NBT, and the value of IC_（50） is 5.22 μmol·L^-1.

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 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 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.