Electrospray ionization tandem mass spectrometric studies to probe the interaction of Cu(II) with amoxicillin简

This study describes the application of electrospray ionization mass spectrometry(ESI-MS) to investigate copper ion interaction with amoxicillin. ESI mass spectra of Cu–amoxicillin complexes show complex ions at m/z 828, 792, 753, 731, 428, 388 and 366 corresponding to [63Cu+(2A-H)+2H2 O]+, [63Cu+(2A-H)]+, [2A+Na]+, [2A+H]+, [63Cu+(A-H)]+, [A+Na]+and [A+H]+(where A = amoxicillin). Based on the observed m/z values of Cu–amoxicillin complex ions, it is found that the Cu–amoxicillin ratios are 1:1 and 1:2, and the copper ions exhibited three feasible coordination numbers(2, 4 and 6) with amoxicillin complexes. The structures and coordination numbers of copper–amoxicillin complex ions were probed from their collisionally activated dissociation(CAD) spectra. Based on these results, it is confirmed that the copper ions could form stable tetrahedral and octahedral complexes with amoxicillin. This study validates the applicability of ESI-MS for probing copper–amoxicillin complex ions.     

由4，4＇-联二吡啶桥联α,β-不饱和酸铜形成铜（II）的一维配位聚合物

A methanol solution of 4,4‘-bipyridine reacts with Cu2A4(H2O)2 to yield coordination polymers of general formula: [Cu2A4(bipy)]n [A: CH2=C(Me)CO2^- (1), CH2=CHCO2^- (2); bipy: 4,4‘-bipyridine]. They were characterized by elemental analyses, IR spectra and thermal analyses. The X-ray structure analyses of 1 show a one-dimensional chain structure where the binuclear structural units Cu2[CH2=C(Me)CO2]4 are bridged by 4,4‘-bipyridine molecules. Furthermore, the binuclear units between adjacent layers can form micropores. The temperature-dependent magnetic susceptibility of 1 indicates that the strong antiferromagnetic interaction exists between copper(Ⅱ) atoms in the binuclear units.     

Synthesis and Crystal Structure of a Dinuclear Cu(Ⅱ) Complex [Cu(C_(13)H_9N_2O)Cl]_2·(CH_3CN)_2 with Ligand 2-Benzimidazol

A new dinuclear copper complex, [Cu(C13H9N2O)Cl]2·(CH3CN)2 (C30H24Cl2Cu2N6O2), has been synthesized and characterized by X-ray structure determination. It crystallizes in the tricli- nic system, space group P1, with a = 7.6677(14), b = 9.2375(17), c = 11.227(2) , α = 81.338(3), β = 88.173(4), γ = 66.199(3)o, V = 718.9(2) 3, Z = 1, Mr = 698.53, F(000) = 354, Dc = 1.613 g/cm3, μ(MoKα) = 1.705 mm-1, the final R = 0.0645 and wR = 0.1364 for 2474 unique reflections with 1809 observed ones (I > 2σ(I)). In the title complex, each copper(II) atom is located at the center of a distorted tetrahedron consisting of four coordinate atoms (one nitrogen atom, two oxygen anions, and one chlorine atom). Two copper(II) atoms are bridged by two oxygen anions (O(1) and O(1a)) of two phenolates to form a Cu(II)–Cu(II) binuclear entity, and the distance between two copper(II) atoms is 3.0144(15) .     

Synthesis, structure and characterization of binuclear copper(Ⅱ) complexes

At room temperature, dibenzoyl peroxide undergoes oxidative addition reaction with metallic copper powder and pyridine N-oxide (triphenylphosphine oxide or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolin) which affords the last products as binuclear copper(II) complexes, [Cu(C5H5NO)-(C6H5COO)2]2(1), [Cu(OPPh3)(C6H5COO)2]2(2) and [Cu(C6H5COO)(C26H2oN2)](3, C26H2oN2 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolin). The structure of the complexes were characterized by elemental analyses, IR spectra, TG-DTA and magnetic property. Crystals(1) are triclinic, space group P1,a=0.92617(36),b=1.06973(17), c=1.08813(29) nm, a=59.60(2)°, β=74.83(3)°,γ=72.80(2)°, V=0.880 nm3, Dc=1.520 g/cm3, Z=1, R=0.044, Rw=0.048, Mr=805.78, 3477 reflections with I > 3σ(I). Each copper(Ⅱ) ion is coordinated by two bridging bidentate benzoate ligands and one pyridine N-oxide or triphenylphosphine oxide to form dimeric binuclear molecules. The structure of the compound(1) shows a clear centre of symmetry.     

Structural analysis of [Bmim]2CuCl4 ionic liquids in the presence of water and ethanol by XAFS technique

The structure of [Bmim]2Cu Cl4 ionic liquids(Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2 O and C2H5 OH was investigated using X-ray absorption fine structure(XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2Cu Cl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2 O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2Cu Cl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]2Cu Cl4/C2H5 OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2Cu Cl4. The structure of [Bmim]2Cu Cl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.     

Synthesis and Crystal Structure of a Copper(II) Complex with α-Hydroxylated Acid, [Cu(C_(14)H_8O_3)(C_5H_(13)NO)(H_2O)].0.5H_2O

1 INTRODUCTION There has been considerable interest of copper(II) -hydroxylate complexes in the structural chemistry and biochemistry. There are two structural types in copper(II) -hydroxylate com- plexes: mononuclear[1~6] and dinuclear structure[7~9]. The present work is a part of our study on the copper complexes of -hydroxylated acid and reports the synthesis and structure of a mononuclear copper(II) complex with 9-hydroxy- fluorene-9-carboxylato acid, [Cu(C14H8O3)(C5H13- NO)(H…     

SYNTHESIS, STRUCTURE AND MAGNETISM OF μ-OXAMIDO BINUCLEAR COPPER(Ⅱ) COMPLEXES

Two new binuclear copper(Ⅱ) complexes, [Cu(oxpn)CuL](ClO_4)_2, have been synthesizedand characterized, where oxpn is N,N' bis(3-aminopropyl)oxamido and L is 1,10-phenan-throline (phen) or 5-nitro-1,10-phenanthroline (NO_2-phen). The crystal structure and vari-able-temperature magnetic susceptibility (4- 300 K) of the Complex (L=phen) have beendetermined. Crystal data: orthorhombic system, space group Pnma, with a = 10.433(1), b11.458(2), c = 21.999(2)A, z = 4. Every copper(Ⅱ) ion is in a square pyramidal environment.The two copper(Ⅱ) ions are linked by μ-oxamido bridge and the separation of them is 5.208A. The singlet-triplet energy gap J was found equal to -452.92cm~(-1), indicating that astrongantiferromagnetic spin-exchange interaction operates between the copper(Ⅱ) ions.     

Synthesis,Crystal Structure and Properties of a New Binuclear Copper(Ⅱ) Complex with 5-Oxo-4-oxa-tricyclo[4.2.1.0]nonane-9-carboxylic Acid(TNCA)

A new binuclear copper(Ⅱ) complex [Cu_2(Hpt)_2(TNCA)_2(H_2O)_2]·4 H_2O(1) has been synthesized with copper acetate, 5-oxo-4-oxa-tricyclo[4.2.1.0]nonane-9-carboxylic acid(TNCA) and 3-(pyridin-2-yl)-1,2,4-triazole(Hpt). It crystallizes in the triclinic space group P~-_1, with a = 8.8199(18), b = 14.278(3), c = 15.269(3) ?, α = 76.21(3)o, β = 81.07(3)o, γ = 76.07(3)o, V = 1802.7(6) ?~3, Dc = 1.636 g/cm~3, Z = 2, F(000) = 916, the final GOOF = 1.051, R = 0.0556 and wR = 0.1388. The whole molecule consists of two copper ions bridged by two μ_2-η~1:η~0-3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of the Cu(1) ion is CuO_2N_3, giving a distorted square pyramidal geometry. 1 exhibits antiferromagnetic interaction between Cu(Ⅱ) ions, the electron transfer of 1 is irreversible in electrode reactions and the TG analysis shows that 1 is stable below 440 K.     

Effect of copper loading on texture,structure and catalytic performance of Cu/SiO2 catalyst for hydrogenation of dimethyl oxalate to ethylene glycol

Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation (UHDP) technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu +.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu+,respectively.The proper copper loading (30 wt%) provides with the highest ratio of Cu + /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.     

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.     

Highly Selective Salicylate Membrane Electrode Based on N,N′-(Aminoethyl)ethylenediamide Bis(2-salicylideneimine)Binuclear Copper(Ⅱ) Complex as Neutral Carrier

A new ion selective electrode for salicylate based on N,N'-(aminoethyl)ethylenediamide bis(2-salicylideneimine)binuclear copper(Ⅱ)complex[Cu(Ⅱ)_2-AEBS]as an ionophore was developed.The electrode has a linear range from1.0×10~(-1) to 5.0×10~(-7) mol·L~(-1) with a near-Nernstian slope of(-55±1)mV/decade and a detection limit of 2.0×10~(-7) mol·L~(-1) in phosphorate buffer solution of pH 5.0 at 25℃.It shows good selectivity for Sal~- and displaysanti-Hofmeister selectivity seoquence:Sal~->SCN~->ClO_4~->I~->NO_2~->Br~->NO_3~->CI~->SO_3~(2-)>SO_4~(2-)The proposed sensor based on binuclear copper(Ⅱ)complex has a fast response time of 5-10 s and can be used forat least 2 months without any major deviation.The response mechanism is discussed in view of the alternating cur-rent(AC) impedance technique and the UV-vis spectroscopy technique.The effect of the electrode membranecompositions and the experimental conditions were studied.The electrode has been successfully used for the deter-mination of salicylate ion in drug pharmaceutical preparations.     

Synthesis, Characterization, Spectroscopic and Electrochemical Properties of New Mono- and Binuclear Copper（Ⅰ） Complexes with Substituted 2,2′-Bipyridine

The mono- and binuclear Cu(Ⅰ) complexes with substituted 2,2′-bipyridine and iodide ligands, [CuL2]BF4(L=4-methoxycarbonyl-6-(4-methylphenyl)-2,2′-bipyridine (a), 6-(4-hydroxymethylphenyl)-2,2′-bipyridine (b) and 6-(4-methoxylphenyl)-2,2′-bipyridine (c)) and [Cu2(μ-I)2L2] were prepared, and the crystal structures of the complexes were obtained from signal-crystal X-ray diffractional analysis. The spectroscopic properties of the complexes in dichloromethane are dominated by low energy MLCT bands from 360 to 650 nrn. The electrochemical studies of mononuclear complexes reveal that the complexes have stable copper(Ⅰ) state.     

A New Dinuclear Cu(Ⅱ) Complex of a Ligand with Benzimidazole Group─Synthesis and Crystal Structure

A new dinuclear copper complex, [Cu(C9H11N3)Cl2]2 (C18H22Cl4Cu2N6), has been synthe- sized and characterized by X-ray structure determination. It crystallizes in the triclinic P1 space group with a = 7.526(3), b = 9.473(4), c = 9.535(3) , α = 117.214(10), β = 108.251(9), γ = 91.560(6)o, V = 562.3(4) 3, Z = 1, Mr = 591.30, F(000) = 298, Dc = 1.746 g/cm3, μ(MoKα) = 2.385 mm-1, the final R = 0.0577 and wR = 0.1248 for 2188 unique reflections with 1629 observed ones (I > 2σ(I)). In the title complex, each copper(II) atom is located at the center of a distorted trigonal bipyramid of five coordination atoms (two nitrogen and three chlorine atoms). Two copper(II) atoms were bridged by two chlorine anions (Cl(2) and Cl(2a)) to form a Cu(II)-Cu(II) binuclear entity with the distance between two copper(II) atoms of 3.398 .     

Crystal Structure and Herbicidal Activity of 5,7-Dimethoxy-(2,4-dichlorophenoxyacetyl- imino)-2H-1,2,4-thiadiazolo[2,3-a]pyrimidine

1 INTRODUCTION 2H-1,2,4-Thiadiazolo[2,3-a]pyrimidine compounds are a new series of ALS inhibiting agents besides sulfonylurea herbicide. Their herbicidal activity is similar to that of sulfonylurea herbicide, but be- cause of weak S–N bond existing in 2H-1,2,4-thiadi- azolo[2,3-a]pyrimidine ring, which is advantageous for the absorption and metabolism of vegetable, 2H- 1,2,4-thiadiazolo[2,3-a]pyrimidine herbicides have better selectivity[1～3]. At present, reports about the synthesis…     

Synthesis,Crystal Structure and Property of a Binuclear Copper Complex [Cu_2L_2(pht)_2]_2·H_2O

A new binuclear copper complex, [Cu2L2(pht)2]2·H2O(Hpht = 5,5-diphenylhydantoin, i.e. phenytoin; L = 2-diethylaminoethanol), has been synthesized by the solvothermal method, and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 31.918(3), b = 12.9222(15), c = 19.868(2) , β = 98.762(2)o, V = 8098.8(16) 3, Dc = 1.429 Mg/m3, Z = 4, F(000) = 3640, μ = 1.107 mm-1, R = 0.0560 and wR = 0.1276(I 2(I)). Each copper(Ⅱ) in a molecule is coordinated with N and O atoms from ligand L and N atom from ligand Hpht in a tetradentate manner. Moreover, two copper(Ⅱ) centers are bridged by two O atoms of hydroxyl groups from two L ligands to form a slightly distorted binuclear {Cu2O2} diamond configuration. In addition, the interaction of this complex with calf thymus DNA(CT-DNA) was investigated by UV-vis spectrum and viscometry, and the complex may bind to DNA through intercalation.     

Synthesis, crystal structure and magnetic properties of the binuclear copper (II) complex of a new bis (1, 4, 7,10-tetraazacyclodoclecane) ligand

A new binucleating macrocyclic ligand 2,6-bis (1,4,7,10-te-traazacyclododecan-10-ylmethyl)methoxy-benzene (L) and its binuclear copper (II) complex, [ Cu2LBr2 ] (ClO4 )2 · 3H2O (1), was prepared and the structure was determined by X-ray crystallography. Complex 1 crystallizes in monoclinic crystal system, P21/n space group with a = 0.8206(3), b = 2.0892(8), c = 2.3053(7) nm, β=95.83(2)°, V = 3.932 nm3, Mr = 1017.57, Z = 4, Dc= 1.692 g/cm3, and R = 0. 0489, Rw= 0.0552 for 6571 observed reflections with I≥2σ (I). Both of the copper(II) centers are coordinated by four amine nitrogen donors of cyclen subunits and a bromide an-ion, and each copper (II) ion is in a square-pyramidal coordination environment. Variable temperature magnetic susceptibility studies indicate that there exists weak intramolecular an-tiferro-magnetic coupling ( - 2J = 2.06 cm-1) between the two copper(n) centers.     

Synthesis and Crystal Structure of a Dinuclear Cu(Ⅱ) Complex [Cu(C13H9N2O)Cl]2·(CH3CN)2 with Ligand 2-Benzimidazol

A new dinuclear copper complex, [Cu(C13H9N2O)Cl]2·(CH3CN)2 (C30H24Cl2Cu2N6O2),has been synthesized and characterized by X-ray structure determination. It crystallizes in the triclinic system, space group P1-, with a = 7.6677(14), b = 9.2375(17), c = 11.227(2) (A), α = 81.338(3),β= 88.173(4), γ = 66.199(3)°, V = 718.9(2) (A)3, Z = 1, Mr = 698.53, F(000) = 354, Dc = 1.613 g/cm3,μ(MoKα) = 1.705 mm-1, the final R = 0.0645 and wR = 0.1364 for 2474 unique reflections with 1809 observed ones (I＞ 2σ(Ⅰ)). In the title complex, each copper(Ⅱ) atom is located at the center of a distorted tetrahedron consisting of four coordinate atoms (one nitrogen atom, two oxygen anions,and one chlorine atom). Two copper(Ⅱ) atoms are bridged by two oxygen anions (O(1) and O(1a)) of two phenolates to form a Cu(Ⅱ)-Cu(Ⅱ) binuclear entity, and the distance between two copper(Ⅱ)atoms is 3.0144(15) (A).     

A Novel Binuclear Cu（Ⅱ） Complex with Nitroxide Radicals Exhibiting Ferromagnetic Interactions

A new binuclear Cu(Ⅱ) complex with nitronyl nitroxide radicals [Cu(NIT3Py)2Cl2]2(NIT3Py = 2-(3'-pyridinyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized and structurally characterized by X-ray diffraction analysis.It crystallizes in monoclinic,space group C2/c with a = 38.483(4),b = 7.2450(8),c = 27.559(3) ,β = 134.0180(10)°,V = 5525.6(10) 3,C48H64Cl4Cu2N12O8,Mr = 1206.00,Z = 4,Dc = 1.450 g/cm3,μ(MoKα) = 1.025 mm-1,F(000) = 2504,S = 1.066,the final R = 0.0471 and wR = 0.1121 for 3286 observed reflections(I > 2σ(I)).The title complex consists of centrosymmetric dinuclear units [Cu(NIT3Py)2Cl2]2,in which the copper ions are square-pyramidally coordinated by two pyridyl nitrogen atoms of two radical ligands and three chlorine anions,two of which bridge the copper ions.The magnetic measurements show ferromagnetic interactions between the copper ions and the radical ligands.     

Exogenous bridge and tautomer effects on magnetic interaction of binuclear copper(II) complexes of μ-phenolato Schiff bases

Four enol-form binuclear copper complexes with different exogenous bridges, [Cu2(L)(μ-Cl)] (1), [Cu(L)(μ-N3)]· DMF (2), [Cu2(L)(μ-OCH3)] (3) and [Cu2(L)(μ-C3H3N2)]· 1/2C2H5OH (4), where L is the trivalence anion of binucleating ligand 2,6-diformyl-4-methylphenol di(tenzoylhydrazone), have been synthesized and characterized. Crystal data for complex (3) are as follows: space group P1- , a=0.8294(1), 6=0.9333(3), c= 1.473 6(6) nm, α=79.51(3)°, β=80.93(2)°,γ=81.32(2)°, Z=1. The magnetic measurements indicated that the effect of exogenous bridging ligands on magnetic interaction is corresponding to that in spectrochemical series. The effect of enol- and keto-form tautomer on magnetic interaction was explained from the point of view of structural factors and electron effects by using molecular mechanks and quantum chemistry calculations.     

Mixed-valence copper coordination polymers based on CuSCN or CuN_3 as bridging motifs

Two novel mixed valence copper coordination polymers, [Cu(2-pac)2(CuN3)(H2O)]n (1) and [Cu(2-pac)2(CuSCN)2]n (2), have been prepared through hydrothermal synthesis and analyzed for structure determination, which exhibit two and three-dimensional structures respectively. In complex (1), zigzag chains of [CuN3]n running parallel to the c direction are interconnected by Cu(2pac)2 to form a two-dimensional layer structure. In complex (2), the arrangement ofμ-1,1,3 bridging thiocyanate ligand leads to the formation of ten-membered Cu-SCN-Cu-S-Cu-NCS rings, and each Cu atom is further linked by Cu(2-pac)2 to afford a three-dimensional configuration.