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《Journal of Coordination Chemistry》2012,65(4):540-549
The treatment of 3-ammonium-1-hydroxypropylidene-1,1′-bisphosphonate (H7ahdp) and 4,4′-bipy with CuCl2?·?2H2O resulted in a metal phosphonate [Cu(H5ahdp)?·?H2O] n . Its crystal structure has been characterized by single X-ray crystallography. Although there is no 4,4′-bipy in the lattice structure, it plays a very important role in forming the one-dimensional chain of the polymer. Hydrogen bonds link the chains into a 3D network. The dinuclear secondary building units are observed in the compound. The determination of variable-temperature magnetic susceptibilities (5?~?300?K) shows weak intrachain antiferromagnetic coupling between copper(II) centers. The magnetic data were fitted to the appropriate equations derived from the Hamiltonian H?=??2JS 1 S 2, giving the parameter J?=??25.78?cm?1. Its thermal properties were also investigated. 相似文献
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Taek‐Gyoung Kim Ji‐Woong Park 《Journal of polymer science. Part A, Polymer chemistry》2012,50(9):1851-1860
We synthesize poly(oligoaniline)s consisting of multiple oligoaniline units linked by alkane spacers with their structures and properties controlled over three different oxidation states. tert‐Butoxycarbonyl (t‐BOC)‐protected diamino‐oligoanilines are synthesized and polymerized with diisocyanatoalkanes to produce t‐BOC‐protected prepolymers. We obtain the unprotected poly(oligoaniline)s in leucoemeraldine base, emeraldine base, and emeraldine salt oxidation forms by using different deprotection conditions for each of them. Distinct routes to each oxidation form of poly(oligoaniline)s enable exploitation of the crystalline structure, electrochemical activity, or conductivity, which is expected from the oligoaniline‐based materials, as well as their excellent processability into thin films that arises from their polymeric nature. The results suggest that new functional materials based on poly(oligoaniline)s may be derived by developing efficient synthetic procedures to control the oxidation states, promising for creation of new nanostructured materials with electrochemical activities. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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L. Lizarraga T. Verdejo F.V. Molina F.J. Gonzlez-Vila 《Journal of Analytical and Applied Pyrolysis》2007,80(2):485-488
Pyrolysis–gas chromatography/mass spectrometry (Py–CG/MS) has been applied to study and compare the composition of two electrochemically synthesized polyaniline (PANI) forms: fully reduced leucoemeraldine (LE) and intermediately oxidized emeraldine (EM). The different PANI forms were electrochemically synthesized using cyclic voltammetry. They were dedoped by stirring for 24 h in ammoniacal solutions. Leucoemeraldine and emeraldine pyrograms presented differences in the relative intensity of their fragment signals. Emeraldine pyrograms presented a higher relative intensity of the signals associated to oxidized fragments (i.e. quinone imine) than leucoemeraldine pyrograms. On the other hand, polymer samples synthesized under different anodic potentials showed small differences, consistent with a higher degree of crosslinking at higher anodic potentials. The results obtained indicate that Py–GC/MS may be used for identification among different oxidation states in aryl amine polymers. 相似文献
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《Journal of Coordination Chemistry》2012,65(6):995-1005
Two complexes constructed from aromatic acid and N-heterocyclic ligands have been synthesized by hydrothermal reaction: [Pb(cipt)(NDC)]n (1) [cipt?=?2-(3-chlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, NDC?=?naphthalene-1,4-dicarboxylic acid] and [Pb(ipm)(BDC)2]n (2) [BDC?=?terephthalic acid, ipm?=?5-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-2-methoxyphenol]. Single-crystal X-ray analysis shows that 1 exhibits an interesting arm-shaped chain structure. 1-D ladder chain structure is formed by N–H···O bonding interactions and further into a 2-D network by N–H···O hydrogen bonds and interchain π–π stacking interactions. Complex 2 shows a 2-D butterfly wings structure, which has been rarely reported. The structure in 2 has intermolecular N–H···O interactions, which help in construction of the 3-D framework. In 1, the coordination sphere of Pb(II) is hemi-directed, whereas the Pb(II) geometry in 2 is holo-directed. The solid-state fluorescence spectra of 1 and 2 are also investigated, as well as the ligands cipt and ipm. 相似文献
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Mannar R. Maurya Anil K. Chandrakar Shri Chand 《Journal of molecular catalysis. A, Chemical》2007,270(1-2):225-235
N,N′-Bis(salicylidene)cyclohexane-1,2-diamine (H2sal-dach) reacts with oxovanadium(IV) and copper(II) exchanged zeolite-Y in refluxing methanol to yield the corresponding zeolite-Y encapsulated metal complexes, abbreviated herein as [VO(sal-dach)]-Y and [Cu(sal-dach)]-Y. Spectroscopic studies (IR, electronic and 1H NMR), thermal analysis, scanning electron micrographs (SEM) and X-ray diffraction patterns have been used to characterise these complexes. These encapsulated complexes catalyse the oxidation, by H2O2, of styrene, cyclohexene and cyclohexane efficiently in good yield. Under the optimized conditions, the oxidation of styrene catalysed by [VO(sal-dach)]-Y and [Cu(sal-dach)]-Y gave 94.6 and 21.7% conversion, respectively, where styreneoxide, benzaldehyde, benzoic acid, 1-phenylethane-1,2-diol and phenylacetaldehyde being the major products. Oxidation of cyclohexene catalysed by these complexes gave cyclohexeneoxide, 2-cyclohexene-1-ol, cyclohexane-1,2-diol and 2-cyclohexene-1-one as major products. Conversion of cyclohexene achieved was 86.6% with [VO(sal-dach)]-Y and 18.1% with [Cu(sal-dach)]-Y. A maximum of 78.1% conversion of cyclohexane catalysed by [Cu(sal-dach)]-Y and only 21.0% conversion by [VO(sal-dach)]-Y with major reaction products of cyclohexanone, cyclohexanol and cyclohexane-1,2-diol have been obtained. 相似文献
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Conclusions The stability of the hydroxo complexes for group (I–IV)B metals in different oxidation states is a function of the electrostatic interaction of the central metal ion and the hydroxyl anion. An equation was obtained which relates the hydrolysis constant and the radius of these ions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1971–1973, September, 1985. 相似文献
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Hydrothermal reactions of cadmium(II) chloride with three amino-diphosphonic acids, C6H5CH2N(CH2PO3H2)2 (H4L1), C6H5CH2CH2N(CH2PO3H2)2 (H4L2) and 4-CH3-C6H4CH2N (CH2PO3H2)2) (H4L3) resulted in three new metal amino-diphosphonates, namely, Cd(H3L1)2, 1 Cd(H3L2)2·2H2O 2 and Cd(H3L3)23. In all three complexes, the Cd(II) ion is octahedrally coordinated by six phosphonate oxygen atoms from six ligands. Complexes 1 and 3 have a similar structure in which the CdO6 octahedra are cross-linked by bridging ligands into a double chain along the c-axis, such double chains are further interlinked via hydrogen bonds between non-coordinated phosphonate oxygen atoms to form 〈100〉 and 〈200〉 layers with the phenyl groups of the ligands orientated toward the interlayer space. The structure of complex 2 features a 〈100〉 cadmium(II) diphosphonate layer. The effects of the substitute groups attached to the amine groups on the structures of the metal phosphonates are also discussed. 相似文献
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Xiu-Li Wang Hong-Yan Lin Guo-Cheng Liu Hai-Yan Zhao Bao-Kuan Chen 《Journal of organometallic chemistry》2008,693(16):2767-2774
Two novel coordination polymers [Cu3(1,3-BDC)4(Dpq)2] (1) and [Cu2(BTC)(OH)(Dpq)2] · H2O (2), have been hydrothermally synthesized by self-assembly of aromatic polycarboxylate ligands 1,3-H2BDC (1,3-H2BDC = 1,3-benzenedicarboxylate) or H3BTC (H3BTC = 1,3,5-benzenetricarboxylate), chelating ligand Dpq (Dpq = dipyrido[3,2-d:2′,3′-f]quinoxaline), and copper chloride. X-ray diffraction analysis reveals that each trinuclear CuII cluster is bridged by two coordination modes of 1,3-BDC ligands to form one-dimensional (1-D) chain structure in complex 1. Complex 2 possesses a two-dimensional (2-D) layer network composed of dinuclear [Cu2(OH)(Dpq)2] unit and bridging ligand BTC. The adjacent chains for 1 or the adjacent layers for 2 are further linked by π-π stacking interactions to form the three-dimensional (3-D) supramolecular frameworks. Moreover, the electrochemical properties of the two copper(II) complexes bulk-modified carbon paste electrodes (Cu-CPEs: 1-CPE and 2-CPE) have been studied, and the results indicate that both Cu-CPEs give one-electron quasi-reversible redox waves in potential range of 600 to −400 mV due to the metal copper ion Cu(II)/Cu(I). The Cu-CPEs have good electrocatalytic activities toward the reduction of nitrite and bromate in 0.1 M pH 2 phosphates buffer solution, and have remarkable long term stability and especially good surface renewability by simple mechanical polishing in the event of surface fouling, which is important for practical application. 相似文献
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Influence of Flexible Bis(benzimidazole) Derivatives on the Self‐assembly of Three Mixed Ligands Silver(I) Coordination Polymers
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Three silver(I) coordination polymers namely, [Ag4(L1)2(1, 4‐ndc)2]n ( 1 ) {[Ag(L2)] · (1, 4‐Hndc) · H2O}n ( 2 ), and {[Ag(L3)(H2O)] · (1, 4‐Hndc)}n ( 3 ) [L1 = 1, 3‐bis(benzimidazol‐1‐ylmethyl)benzene, 1, 4‐H2ndc = 1, 4‐naphthalenedicarboxylic acid, L2 = 1, 3‐bis(5, 6‐dimethylbenzimidazole‐1‐ylmethyl)benzene, L3 = 1, 4‐bis(5, 6‐dimethylbenzimidazole)butane], were hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR spectroscopy, thermogravimetric and XRPD analysis. Complex 1 displays a 1D tube‐like chain, which is packed into a 3D supramolecular network by π–π stacking interactions. Complex 2 features an infinite 1D linear chain. Complex 3 contains a 1D wave‐like chain, which is extended into a 3D supramolecular network through O–H ··· O hydrogen bonding interactions. Moreover, these coordination polymers exhibit catalytic properties for degradation of methyl orange in Fenton‐like processes. 相似文献
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Zhang L Koay M Maher MJ Xiao Z Wedd AG 《Journal of the American Chemical Society》2006,128(17):5834-5850
CopC is a small soluble protein expressed in the periplasm of Pseudomonas syringae pathovar tomato as part of its copper resistance response (cop operon). Equilibrium competition reactions confirmed two separated binding sites with high affinities for Cu(I) (10(-7) > or = K(D) > or = 10(-13) M) and Cu(II) (K(D) = 10(-13(1)) M), respectively. While Cu(I)-CopC was converted cleanly by O2 to Cu(II)-CopC, the fully loaded form Cu(I)Cu(II)-CopC was stable in air. Variant forms H1F and H91F exhibited a lower affinity for Cu(II) than does the wild-type protein while variant E27G exhibited a higher affinity. Cation exchange chromatography detected each of the four different types of intermolecular copper transfer reactions possible between wild type and variant forms: Cu(I) site to Cu(II) site; Cu(II) site to Cu(I) site; Cu(I) site to Cu(I) site; Cu(II) site to Cu(II) site. The availability of an unoccupied site of higher affinity induced intermolecular transfer of either Cu(I) or Cu(II) in the presence of O2 while buffering concentrations of cupric ion at sub-picomolar levels. Crystal structures of two crystal forms of wild-type Cu(I)Cu(II)-CopC and of the apo-H91F variant demonstrate that the core structures of the molecules in the three crystal forms are conserved. However, the conformations of the amino terminus (a Cu(II) ligand) and the two copper-binding loops (at each end of the molecule) differ significantly, providing the structural lability needed to allow transfer of copper between partners, with or without change of oxidation state. CopC has the potential to interact directly with each of the four cop proteins coexpressed to the periplasm. 相似文献
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S. S. Ostakhov S. L. Khursan Yu. I. Murinov T. R. Nugumanov R. R. Kayumova S. F. Petrova 《High Energy Chemistry》2017,51(1):32-37
A spectral fluorescence study of photoinduced reactions in aqueous solutions has been carried out in order to examine the mechanisms of the oxidation of 5-hydroxy-6-methyluracil (I) in the ground and electronically excited states by molecular oxygen in the presence of copper(II) chloride. It has been found that 5,5,6-trihydroxy-6-methylpyrimidine-2,4-dione (II) is formed upon the photolysis of I. The spectral parameters (λmax) and the quantum yields (φ) of fluorescence (FL) of compounds I (φ = 8 × 10–4; λmax = 362 nm) and II (φ = 17 × 10–4; λmax = 306, 330 nm) have been determined. A reaction scheme was proposed, according to which the photooxidation of I occurs through the steps of the generation of the radical cation I ?+ and the superoxide anion О 2 ?- with the subsequent formation of 5,5,6-trihydroxy-6-methylpyrimidine-2,4-dione. The catalytic and inhibitory effects of Cu(II) ions on the oxidation of 5-hydroxy-6-methyluracil in the ground and electronically excited states, respectively, by the oxygen radical anion О 2 ?- have been revealed. 相似文献
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Selçuk Demir Hamide Merve Çepni Małgorzata Hołyńska Muammer Kavanoz Fatih Yilmaz Yunus Zorlu 《Journal of Coordination Chemistry》2017,70(19):3422-3433
Via an oxidation reaction of Cu(I) iodide with pyridine-2,6-dicarboxylic acid (H2L) in DMF three copper(II) complexes, [(CH3)2NH2]2[CuL2] (1), K2[CuL2]?H2L?H2O (2) and [Cu(L)(H2O)]n (3), were synthesized and characterized. The structures of 1–3 were determined by single crystal X-ray diffraction studies. In-situ DMF decomposition produces dimethylamine base under solvothermal conditions and a proton transfer reaction takes place for the complex formation of 1. 3-D networks are stabilized in 1 and 2 via hydrogen bonds. Complex 3 is a 1-D coordination polymer with Cu-O semi-coordination bonds. Thermal decomposition of the complexes results in the corresponding metal oxides. Also, the electrochemical behavior of 1 was determined to be a metal-centered and diffusion-controlled, one-electron reduction process. 相似文献
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Shuai Zhang Hanhui Zhang Xiaochuan Chai Ruiqing Sun 《Journal of solid state chemistry》2008,181(12):3327-3336
The hydrothermal synthesis and structural characterization of five copper iodides derived from chelated ligands, 1, 10-phenanthroline (phen), ethylenediamine (en) and 1, 3-propanediamine, are reported. Except monovalent copper compound 1 ((phen)Cu3I31), other four compounds ([Cu(phen)2I][CuI2] 2, [Cu(phen)2I][Cu3I4] 3, [Cu(en)2][Cu4(phen)2I6] 4 and [Cu(1, 3-propanediamine)2][CuI2]25) are mixed-valent Cu(I)-Cu(II) compounds by partially auto-oxidated from Cu(I). Supramolecular frameworks of these compounds can be assembled by C/N-H?I hydrogen bonds, Cu(I)-Cu(I) interaction, weak Cu-I semicoordinate interaction, C-H?π and π-π stacking interactions. It's noteworthy that we find hydrothermal synthesis under higher pH value, higher synthesis temperature and longer reaction time can obtain higher ratio of Cu(I)/Cu(II) copper iodides and organic ligand with lower steric hinderance is prone to coordinated with divalent copper to form cation unit. Finally, the fluorescent study shows 1 exhibits intense orange-red luminescence with long lifetime at 293 K and more intense emission and longer lifetime at 77 K. Moreover, the room temperature EPR spectra of above five compounds not only show the valence of copper but demonstrate the coordination environment of Cu(II) centre. 相似文献
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Elisaveta V. Lider Eugenia V. Peresypkina Anton I. Smolentsev Valentina N. Elokhina Tatyana I. Yaroshenko Alexander V. Virovets Vladimir N. Ikorskii Ludmila G. Lavrenova 《Polyhedron》2007
Novel copper(II) complexes, molecular [Cu6(μ6-Cl)(μ3-OH)2(μ-L)6Cl9(H2O)3] · 3H2O (1) and polymeric [Cu(μ-L)(μ-OH)(H2O)2]Cl (2) (L = 4-(4-hydroxyphenyl)-1,2,4-triazole), have been prepared and characterized by X-ray structural analysis. Compound 1 appears to be an unusual example of a chloride ion with six equal Cu–Cl distances of 2.8397(3) Å. It has also been characterized by X-ray powder diffraction and magnetic measurements. Both complexes have distorted octahedral configurations of copper ions; the coordination cores are CuN2Cl2O2 or CuN2Cl3O (1) and CuN2O4 (2). 相似文献
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A spectroscopic investigation of the products formed in the reaction of emeraldine base (EB-PANI) with copper(II) ions in dimethylacetamide (DMA) is presented. It is well known that metal cations can dope emeraldine base polyaniline (EB-PANI) through a pseudo-protonation reaction. Resonance Raman, UV–vis-NIR, and EPR data, obtained for Cu2+/EB-PANI solutions prepared using CuCl2·2 H2O, Cu(NO3)2· 3 H2O or Cu(CH3COO)2·H2O as Cu2+ sources, showed that the species formed in reactions of EB-PANI and Cu2+ ions are dependent on the anions of the copper salt employed. EPR spectra pointed out that the environments of Cu2+ ions with acetate, chloride or nitrate as anions in DMA solution are distinct. Resonance Raman and UV–vis-NIR data demonstrated that the main reactions are the oxidation of EB-PANI to pernigraniline base (PB-PANI) and doping of EB-PANI to ES-PANI (emeraldine salt) when a direct coordination of Cu2+ ions to PANI exists. With nitrate as very weak coordinating anion, ES-PANI is formed preferentially. When copper chloride is used, both oxidation and doping of EB-PANI are verified. Conversely with acetate, the dimeric cage structure of this copper salt is preserved in solution, and oxidation of EB-PANI to PB-PANI is the only observed reaction. These results demonstrate the possibility of modulating the products of reaction between Cu2+ ions and EB-PANI in DMA solution by changing the counter ion of the Cu2+ source. 相似文献
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Xiuli Wang Yongqiang Chen Guocheng Liu Hongyan Lin Jinxia Zhang 《Journal of solid state chemistry》2009,182(9):2392-2401
In our efforts to tune the structures of Mn(II) complexes by selection of organic carboxylic acid ligands, six new complexes [Mn(PIP)2Cl2] (1), [Mn(PIP)2(4,4′-bpdc)(H2O)]·2H2O (2), [Mn(PIP)2(1,4-bdc)] (3), [Mn(PIP)(1,3-bdc)] (4), [Mn(PIP)2(2,6-napdc)]·H2O (5), and [Mn(PIP)(1,4-napdc)]·H2O (6) were obtained, where PIP=2-phenylimidazo[4,5-f]1,10-phenanthroline, 4,4′-H2bpdc=biphenyl-4,4′-dicarboxylic acid, 1,4-H2bdc=benzene-1,4-dicarboxylic acid, 1,3-H2bdc=benzene-1,3-dicarboxylic acid, 2,6-H2napdc=2,6-naphthalenedicarboxylic acid, 1,4-H2napdc=1,4-naphthalenedicarboxylic acid. All complexes have been structurally characterized by IR, elemental analyses, and single crystal X-ray diffraction. Structural analyses show that complexes 1 and 2 possess mononuclear structures, complexes 3, 4, and 5 feature chain structures, and complex 6 exhibits a 2D (4,4) network. The structural difference of 1–6 indicates that organic carboxylate anions play important roles in the formation of such coordination architectures. Furthermore, the thermal properties of complexes 1–6 and the magnetic property of 4 have been investigated. 相似文献
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Olena Palasyuk 《Journal of solid state chemistry》2010,183(4):814-13539
Two copper tantalates, Cu5Ta11O30 (1) and Cu3Ta7O19 (2), were synthesized by solid-state and flux synthetic methods, respectively. A synthetic route yielding 2 in high purity was found using a CuCl flux at 800oC and its structure was characterized using powder X-ray diffraction (XRD) data (P63/m (no. 176), Z=2, a=6.2278(1) Å, and c=20.1467(3) Å). The solid-state synthesis of 1 was performed using excess Cu2O that helped to facilitate the growth of single crystals and their characterization by XRD (P6¯2c (no. 190), Z=2, a=6.2252(1) Å, and c=32.516(1) Å). The atomic structures of both copper tantalates consist of alternating single and double layers of TaO7 pentagonal bipyramids that are bridged by a single layer of isolated TaO6 octahedra and linearly-coordinated Cu+. Measured optical bandgap sizes of ∼2.59 and ∼2.47 eV for 1 and 2 were located well within visible-light energies and were consistent with their orange-yellow colours. Each also exhibits optical absorption coefficients at the band edge of ∼700 and ∼275 cm−1, respectively, and which were significantly smaller than that for NaTaO3 of ∼1450 cm−1. Results of LMTO calculations indicate that their visible-light absorption is attributable mainly to indirect bandgap transitions between Cu 3d10 and Ta 5d0 orbitals within the TaO7 pentagonal bipyramids. 相似文献
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Helena M. Carapua Olga M. S. Filipe Joo E. J. Simo Arnold G. Fogg 《Journal of Electroanalytical Chemistry》2000,480(1-2)
Cu2+ is reduced in the presence of nitroprusside to form two Cu(I) reduced nitroprusside species at about +0.050 V (pH 7.6). These species are reduced further at about −0.60 V. The two species are formed by an EC mechanism, and the species are believed to be [CuIFe(CN)4NO]−, which predominates in acidic solution, and [CuIFe(CN)5NO]2−, which predominates in alkaline solution. These conclusions are supported by cyclic voltammetric and bulk electrolysis/coulometric experiments. 相似文献