Synthesis and Structure of the Copper(Ⅰ) Complex 〔Cu(PPh_3)_2(BH_4)〕

1　INTRODUCTIONCopper( ) displayswide diversity in itsstructuralchemistry,the copper coor dination number ranging from two to four.Procedures to synthesize copper( )complexes itself are of great interest because of the diversity of products resultingfrom almost the same methodology.Ithas long been accepted that because copper( ) complexesare diamagnetic,and hence,provideno opticalabsorption bands( nod d transition is encountered) for a copper( ) ion with a d10 configuration and noelect…     

PREPARATIVE AND STRUCTURAL STUDIES ON THE SUPERCONDUCTING PHASE YBa_2Cu_3O_(7-d)

Reasonably homogeneous samples were obtained by following the formula Y_(0.334)Ba_(0.666)CuO_(3-y) andusing citric acid as a complex-forming agent to improve the dispersion of the metal oxides. We havealso found that the variant condition in preparative procedure leads to variant deviation from tetrago-nality and that more pronounced deviation gives better superconducting properties. The crystal structure determined from X-ray powder diffraction diagrams confirms the stoichiom-etry of the metal ions and gives the positions of the oxygen atoms. The orthorhombic or pseudo-tetragonal unit cell with a=3.893, b= 3.813 and c= 11.687 A contains YBa_2Cu_3O_7. It is composed ofthree perovskite cubes with three copper atoms at their corners, the two barium atoms at the centers ofthe top and bottom cubes, and the yttrium at the center of the unit cell. The oxygen atoms sit on centersof cube edges. The positions (0 0 1/2) are vacant. The vacancies represented by (0(1/2)0) cause the ar-rangement of atoms to lose tetragonal symmetry, and have far-reaching effect for this phase. The yttriumand barium atoms are coordinated in a cuboctahedron respectively with four equatoria oxygen atoms at(0 0 1/2) and two at (0 1/2 0) removed. In the light of bond valence theory we can infer from the in-teratomic distances Y-O, Ba-O and Cu-O that the occupancy of the oxygen atoms at (1/2 0 0) is wellbelow unity while the positions (0 0 1/2) are vacant, the formula of the phase is YBa_2Cu_3O_(7-d), thefraction of Cu(Ⅱ) and (Ⅲ) for the set of copper at (0 0 0) is respectively d/0.5 and (1-d/0.5), and0.2相似文献   

Tin(II) Chloride Dihydrate Catalyzed Groebke Condensation: An Efficient Protocol for the Synthesis of 3-Aminoimidazo[1,2-a]pyridines

The ability of tin(II) chloride dihydrate as a catalyst to promote the three-component condensation reaction from a diversity of aromatic aldehydes, 2-aminopyridines and isonitriles at room temperature is described. This methodology affords a number of 3-aminoimidazo[1,2-a]pyridines in the presence of tin(II) chloride dihydrate as a new and mild Lewis acid catalyst in the multi-component reaction in reasonable yields and short reaction time without any significant optimization of the reaction conditions.     

碱性介质中 (氢) 氧化铜修饰电极电催化氧化蔗糖

 A stable copper (hydr)oxide-modified electrode was prepared in 0.5 mol/L NaOH solution by cyclic voltammetry in the range of -250 to 1 000 mV. It can be used for electrochemical studies in the range of -250 to 1 000 mV without interfering peaks because there is no oxidation of copper. During an anodic potential sweep, the electro-oxidation of saccharose on Cu occurred by the formation of Cu^III and this reaction also occurred in the early stages of the reversed cycle until it is stopped by the negative potentials. A mechanism based on the electro-chemical generation of Cu^III active sites and their subsequent consumption by saccharose was proposed, and the rate law and kinetic parameters were obtained. The charge transfer resistance from theoretical and impedance studies was used to verify the mechanism. Under chronoamperometry regimes, the reaction followed Cottrellian behavior. The transfer of up to 21 electrons was observed in further investigations of the electro-oxidation of saccharose on a (hydr)oxide Cu rotating disk electrode.     

SPECTRAL STUDY ON A NEW 3d_z~2 TYPE COPPER(Ⅱ)COMPLEX OF PHENOLIC POLYMERIC CROWN ETHER

ESR and IR measurements have been carried out for a copper(Ⅱ)complex ofphenolic polymeric crown ether,As a result,the triplet ESR spectrum(S=1)of 3d_z2ground state copper(Ⅱ)ions was first observed for the powder sample.It indicatedthat there existed intramolecular spin-spin interaction betweeen 3d_Z2 groundstate copper(Ⅱ)and copper(Ⅱ)ions.In this binuclear triplet cluster,the axialligntion of one water molecule in a sandwich position to two adjacent copper(Ⅱ)ions was also confirmed by IR spectra,All things considered,a possible structurefor the complex was proposed.     

Synthesis and Crystal Structure of a [Cu(HTren)Cl_2]ClO_4·H_2O Complex (Tren = Tris(2-aminoethyl)amine)

1INTRODUCTION Investigation of the coordination chemistry of copper(II)continues to be stimulated by interest in developing modes for copper proteins and in under-standing the factors which give rise to the seemingly infinite variety of distortions from regular stereo-chemistry observed in Cu(II)complexes[1,2].For more than decades,due to the unique coordination polyhedra and their easy preparation,tripodal copper complexes have attracted much attention in addition to their special chemi…     

Thiocyanate ion selective electrode based on bis(N-3-methylphenyl salicylidenaminato)copper(Ⅱ) ionophore

In this work a PVC membrane electrode based on bis(N-3-methyl phenyl salicylidenaminato)copper(II)as ionophore was prepared.The electrode was tested by inorganic anions and showed good selectivity for thiocyanate ion.This sensor showed Nerstian behavior with a slope of a-59.3 mV per decade at 25℃.The proposed electrode exhibited a wide linear range from 1.0 × 10~(-6) mol/L to 1.0× 10~(-1) mol/L with a detection limit of 5.0×10~(-7) mol/L.The electrode response was independent of pH in the range of 4.0-10.0.The response time is about 9-21s,and the electrode can be used for over 60 days without considerable deterioration.The prepared sensor was applied as an indicator electrode in potentiometric titration of SCN with Ag~+ ion and to determine the thiocyanate in samples of urine and saliva.     

铜(Ⅱ)离子导向的自组装研究

A few copper(Ⅱ) ions or groups have been designed and investigated for metal-assisted self assembly. Reactions of these metal units with a number of linear bridging ligands have led to the production of some dinuclear copper(Ⅱ) complexes and coordination polymers in which metal centers are all five-coordinate in the configuration of a square pyramid or a triangular bipyramid.     

SYNTHESIS OF MESO-TETRA (4-METHOXYPHENYL-3-SULFONATE) PORPHINE AND SPECTROPHOTOMETRIC STUDY OF COLOUR REACTION WITH COPPER

In this paper meso-tetra (4-methoxyphenyl-3-sulpho) Porphine (TMPPS_4) was synthesized and its colour reaction with copper was studied. It was found to be a highly sensitive and highly selective reagent for the direct spectrophotometric determination of ultramicro amount of copper. The apparent molar absorptivity of the complex is 3.72×10~5L/mol·cm. Beer's law is obeyed for Cu(Ⅱ)of 0～1.4μg/10ml. The interference of 21 different ions and 6 kinds of salts were examined and found to be minimal. The complex formation of Cu(Ⅱ) with TMPPS_4 is generally slow at room temperature<<25℃>, but the reaction can be accelerated in the presence of NH_2OH·>HCl and completed within 5min. At PH 5.2 the Soret band of TMPPS_4 overlaps almost completetely with that of the complex. Therefore, the complex formation is taken to completion at this PH. Then the Soret band of TMPPS_4 shifted away from that of the complex by acidification.This simple and rapid method has been successfully applied to the direct determination of Cu in Al-alloys, industrial water, foods and human hair.     

Synthesis and Structure of the Copper(I) Complex Containing Bis(diphenylphosphino)ethane

1 INTRODUCTION Procedures to synthesize copper(I) complexes are of great interest because of the diversity of products resulting from almost the same methodology. It has long been known that four-electron-donor diphosphine compounds Ph2P(CH2)nPPh2 are excellent bidentate ligands[1]. The chelating tendency decreases as the chain length increases, so that for the ligands Ph2P(CH2)nPPh2, the tendency to chelation is the greatest for bis(diphenylphosphino)ethane. Copper(I) displays wide…     

Syntheses of Binuclear Copper(I) Complexes Containing Benzimidazole

1 INTRODUCTION Procedures to synthesize copper(I) complexes are of great interest due to the diversity of products resulting from almost the same methodology. It has been long known that four-electron-donordipho- sphine compounds Ph2P(CH2)nPPh2 are excellent bi- dentate ligands[1, 2]. The chelating tendency of bis- (diphenylphosphino) methane is one of the dipho- sphine ligands most suitable to lock two metal atoms together in close proximity[3]. Many examples of bi- or polynuclear com…     

Initial stages of copper electrodeposition from acidic sulfate solution in the presence of alklpyridinium hydrosulfate ionic liquids

The effect of two alklpyridinium hydrosulfate based ionic liquids(ILs)including N-butylpyridinium hydrogen sulfate(BpyHSO4)and N-hexylpyridinium hydrogen sulfate(HpyHSO4)as additives on the nucleation and growth of copper from acidic sulfate bath was investigated using cyclic voltammetry,chronoamperometric and scanning electron microscopy techniques.Results from cyclic voltammetry indicated that the two studied additives had a blocking effect on copper electrodeposition process and this effect initiated by HpyHSO4was more pronounced in comparison to BpyHSO4.Dimensionless chronoamperometric current-time transients for the electrodeposition of copper from the bath free of additives were in good accord with the theoretical transients for the limiting case of instantaneous three-dimensional nucleation with diffusion-controlled growth of the nuclei.However,the instantaneous nucleation mechanism observed in the additive-free bath was changed to a more progressive one when additives were present in the bath.Surface morphology analysis indicated that alklpyridinium hydrosulfate ILs can induce the formation of leveled and finer grained deposits by the adsorption of additive at the first stages of deposition process,leading to decrease of the nucleation and growth rate of nuclei.     

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) nm3,Dc=1.524 g/cm3,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 ℃.     

Ca(NO3)2•4H2O-catalysed Biginelli Reaction: One-pot Synthesis of 1,2,3,4-Tetrahydropyrimidin-2-ones/pyrimidine-2-thiones under Solvent-free Conditions

The synthesis of 1,2,3,4-dihydropyrimidinone/thione derivatives was achieved in good to excellent yields using calcium(II) nitrate as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, β-keto compounds and urea or thiourea. The reaction was carried out under solvent-free conditions.     

SYNTHESIS OF PPCuPc FILM BY MICROWAVE PLASMA CHEMICAL VAPORIZATION DEPOSITION(MPCVD)

Using a low power microwave generator(W_(max)=100W) and a Surfatron discharge device, Plasma-polymerized copper phthalocyanine (PPCuPc) film was synthesised from monomer copper phthalocyanine(CuPc) by microwave plasma chemical vaporization deposition(MPCVD) with Ar as incorporation gas. The film was characterized by FTIR and ESCA. The role of dissociation of chemical bond in the polymerization process and the influence of substrate temperature and material on deposition were investigated in some detail.     

Adsorption of Thiourea and Formation of Nickel-thiourea Complexes at Initial Stage of Nickel Deposition

The effect of thiourea (TU) on the nickel deposition process was analyzed by means of linear-sweep voltammetry. Raman spectroscopy and infrared reflectance spectroscopy were used to investigate the adsorption of TU and the formation of nickel-TU complexes on copper surface. The experimental results indicate that the nucleation and the preceding conversion step are involved in the deposition of nickel on copper electrodes. TU makes the onset nucleation potential negative due to the formation of nickel-TU complexes. which can accelerate the nickel deposition. Moreover, the S atom in the TU molecule adsorbed on copper surface facilitates the coordination of TU to Ni^2 . Meanwhile, TU might be adsorbed at a flatter orientation if no Ni^2 is on the surface, while at a perpendicular orientation when Ni^2 is coadsorbed.     

4-(2-QUINOLYLAZO)-1, 3-DIHYDROXY-NAPHTHALENE——A NEW SENSITIVE ANALYTICAL REAGENT FOR TRACE COPPER DETERMINATION

The azo compound 4-(2-quinolylazo)-1,3-dihydroxynaphthalene (2-QADNm) has been synthesized and used as a new sensitive spectrophotometric and electroanalytical reagent for determination of trace amounts of copper. In dilute alkaline solutions, 2-QADNm shows a single-sweep polarographic wave at -0.95 V (vs. SCE). In the presence of copper(Ⅱ) two new waves appear at -0.52 and -0.79 V. Using the wave at-0.79 V, a trace amount of copper down to 10~(-8) mol/L can be determined. The electroanalytical characteristics of 2-QADNm and the electrochemical reaction mechanism of the copper(Ⅱ)-2-QADNm complex have been studied in detail by the use of various electrochemical techniques. In alkaline solutions, 2-QADNm forms red complex with copper(Ⅱ) which has an absorption peak at 526 nm, the molar absorptivity being 6.4×10~4 1·mol~(-1)·cm~(-1). In the presence of a non-ionic surfactant the molar absorptivity of this complex is 1.6×10~5 1·mol~(-1)·cm~(-1).     

–ONNO–四齿配体负载铜(Ⅱ)配合物的合成与结构研究:环二酯开环聚合的高效催化剂(英文)

The –ONNO– tetradentate Schiff base ligand N,N'-bis(2-hydroxy-3- methoxybenzaldehyde) benzene-1,2-diamine(HMBBD) has been synthesized. The ligand was attached to copper(Cu-HMBBD) in methanol under N_2 atmosphere to give a mononuclear complex. The reactivity of this complex in the ring-opening polymerization(ROP) of lactide has been studied. The complex has a square planner geometry, as determined by X-ray diffraction studies. The copper complex is highly active towards the ring-opening polymerization of lactide, and the rate of polymerization is heavily dependent on the initiator used. The copper complex allows controlled ring-opening polymerization, as shown by the linear relationship between the percentage conversion and the number average molecular weight. Based on the literature, a mechanism for the ROP of lactide has been proposed.     

Synthesis and magnetic properties of μ-phenolato copper (Ⅱ) binuclear complexes with different exogenous bridges

The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series.     

SOLUTION PROPERTIES OF ANTITUMOR CARBOXYMETHYLATED DERIVATIVES OF α-(1→3)-D-GLUCAN FROM GANODERMA LUCIDUM

Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38～0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.