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1.
Inorg Chem ; 53(1): 73-9, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24328110

RESUMO

The reactions of ligand N'-[(pyridin-2-yl)methylene]pyrazine-2-carbohydrazide (ppcd) with different copper salts (1, acetate; 2, perchlorate; 3, sulfate) in MeOH could afford one acetate-bridge tetranuclear discrete [Cu2(ppcd)(ac)2(H2O)(OH)]2·H2O (1), one-dimensional (1D) chiral chain [Cu(ppcd)]ClO4 (2), and a 1D-decker complex of a trinuclear copper(II) subunit, Cu3(ppcd)2(H2O)4(SO4)2 (3). Single-crystal X-ray analysis revealed that conformation isomerism of the ppcd ligand was associated with the configuration of -N-N- (trans or cis) and could induce the versatile coordination mode in the presence of different anions. The 1D chiral chain was interestingly obtained from the achiral rigid ligand in complex 2. Magnetic studies indicated that the magnitude of the antiferromagnetic coupling can be tuned because of the configuration isomerism [compound 1 is practically diamagnetic at room temperature (J ≈ -1000 cm(-1)), with a strong antiferromagnetic one (J = -255.4 cm(-1)) for 2 in the 1D uniform chain and an antiferromagnetic one (J = -123.6 cm(-1)) for 3 within the trinuclear copper subunit].

2.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 5): m682, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22590164

RESUMO

The asymmetric unit of the title compound, {[Eu(C(7)H(3)NO(4))Cl(CH(3)OH)(2)]·CH(3)OH}(n), contains one Eu(III) ion, one pyridine 2,3-dicarboxylate dianion (PDC), two CH(3)OH mol-ecules coordinating to the metal atom, one coordinating chloride and one lattice occluded CH(3)OH mol-ecule. In the crystal, each PDC anion coordinates to three adjacent Eu(III) ions by the pyridine N and O atoms of the carboxyl-ate groups. The Eu(III) cation is eightfold coordinated by four carboxyl-ate O atoms, one pyridine N atom, two MeOH and one chloride anion in the form of a distorted polyhedron. Extended coordination of the PDC ligand lead to the formation of a two-dimensional coordination polymer parallel to (10-1).

3.
J Phys Chem A ; 115(46): 13316-23, 2011 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-22047477

RESUMO

The putative global minimum structures of Cu-Ag-Au trimetallic clusters with 19 and 55 atoms are obtained by adaptive immune optimization algorithm (AIOA) with the Gupta potential. For the 19-atom trimetallic clusters, the results indicate that all of them have double-icosahedral motifs. For the optimized structures of Cu(13)Ag(n)Au(42-n) (n = 1-41), the clusters can be categorized into 19 Mackay icosahedral structures, 1 6-fold pancake structure, and 21 ring-like structures linked by three face-sharing double-icosahedra. Furthermore, the segregation phenomena of the Cu, Ag, and Au atoms in the Cu-Ag-Au trimetallic clusters are studied to provide useful information for geometric character. Results show that Cu and Ag atoms prefer to locate in the inner-shell and on the surface, respectively, whereas Au atoms mainly locate in the middle-shell and tend to solve into Cu and Ag atoms.

4.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 9): m1121, 2010 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-21588525

RESUMO

In the title compound, [Co(C(19)H(13)ClN(3)O)(2)]NO(3)·2CH(3)OH, the central Co(III) atom in the cation is surrounded by two tridentate ligands in a distorted octa-hedral fashion by four N and two O atoms. Classical O-H⋯O hydrogen bonds link both methanol solvent mol-ecules with the nitrate anion.

5.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 12): m1568-9, 2010 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-21589256

RESUMO

In the title compound, [Co(C(13)H(9)ClN(3)O)(2)]NO(3)·1.5H(2)O, the central Co(3+) atom in the cation is coordinated by four N and two O atoms from the two tridentate ligands in a distorted octa-hedral fashion. In the crystal, the cobalt complex cations are linked to the half-occupied and the fully occupied water mol-ecules, and the nitrate anion via classical inter-molecular O-H⋯O and O-H⋯N hydrogen bonds and weak C-H⋯O contacts.

6.
Artigo em Inglês | MEDLINE | ID: mdl-17574910

RESUMO

Highly luminescent uncoated water-soluble and mono-disperse CdSe nanoparticles (NPs) have been prepared facilely. Uncoated CdSe core NPs possessing a good size distribution was accompanied with long wavelength of fluorescence emission. It is interesting to note that these functionalized NPs are soluble in water medium stably for more than 1 month, and no significant changes were found in the optical characteristics in comparison with fresh CdSe NPs prepared. The functionalized CdSe NPs exhibited strong specific affinity for mercury(II) through their surface functional groups. Based on the significant quenching of fluorescence emission of functionalized CdSe NPs with a long-wavelength 630nm, a simple, rapid and specific detection for Hg(II) was proposed. Under optimum conditions, the response of linearly proportional to the concentration of Hg(II) is between 0mol/L and 1.25x10(-6)mol/L, and the limit of detection is 4.50x10(-9)mol/L. The relative standard deviation (R.S.D.) of six replicate measurements is 2.0% for 2.0x10(-7)mol/L of Hg(II). In terms of fluorescence quenching at 630nm of CdSe NPs, no obvious wavelength shift or no new emission band in presence of Hg(II) at pH 7.50 of phosphate buffer solution were found; furthermore, a significant reduction in absorbance at 230nm of CdSe NPs was first observed in our work. We could speculate that Hg(II) as an effective quencher (even at low concentration) for functionalized CdSe NPs emission suggests that it is capable of directly intercepting one of the charge carriers, thus disrupting the recombination process.


Assuntos
Compostos de Cádmio/química , Corantes Fluorescentes/química , Furanos/síntese química , Mercúrio/análise , Mercúrio/química , Nanopartículas/química , Compostos de Selênio/química , Água/química , Cisteína/química , Furanos/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Tamanho da Partícula , Solubilidade , Soluções , Espectrofotometria , Propriedades de Superfície
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 69(3): 1044-52, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17660001

RESUMO

Strong luminescence CdS quantum dots (QDs) have been prepared and modified with l-cysteine by a facile seeds-assistant technique in water. They are water-soluble and highly stable in aqueous solution. CdS QDs evaluated as a luminescence probe for heavy and transition metal (HTM) ions in aqueous solution was systematically studied. Five HTM ions such as silver(I) ion, copper(II) ion, mercury(II) ion, cobalt(II) ion, and nickel(II) ion significantly influence the photophysics of the emission from the functionalized CdS QDs. Experiment results showed that the fluorescence emission from CdS QDs was enhanced significantly by silver ion without any spectral shift, while several other bivalent HTM ions, such as Hg(2+), Cu(2+), Co(2+), and Ni(2+), exhibited effective optical quenching effect on QDs. Moreover, an obvious red-shift of emission band was observed in the quenching of CdS QDs for Hg(2+) and Cu(2+) ions. Under the optimal conditions, the response was linearly proportional to the concentration of Ag(+) ion ranging from 1.25 x 10(-7) to 5.0 x 10(-6)molL(-1) with a detection limit of 2.0 x 10(-8)molL(-1). The concentration dependence of the quenching effect on functionalized QDs for the other four HTM ions could be well described by typical Stern-Volmer equation, with the linear response of CdS QDs emission proportional to the concentration ranging from 1.50 x 10(-8) to 7.50 x 10(-7)molL(-1) for Hg(2+) ion, 3.0 x 10(-7) to 1.0 x 10(-5)molL(-1) for Ni(2+) ion, 4.59 x 10(-8) to 2.295 x 10(-6)molL(-1) for Cu(2+) ion, and 1.20 x 10(-7) to 6.0 x 10(-6)molL(-1) Co(2+) ion, respectively. Based on the distinct optical properties of CdS QDs system with the five HTM ions, and the relatively wide linear range and rapid response to HTM ions, CdS QDs can be developed as a potential identified luminescence probe for familiar HTM ions detection in aqueous solution.


Assuntos
Compostos de Cádmio/química , Luminescência , Metais Pesados/análise , Sondas Moleculares/química , Pontos Quânticos , Sulfetos/química , Elementos de Transição/análise , Cisteína/química , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Nanopartículas/ultraestrutura , Óptica e Fotônica , Soluções , Espectrometria de Fluorescência , Difração de Raios X
8.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 6): m828, 2008 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-21202510

RESUMO

In the title compound, [Cu(C(6)H(5)N(2)O)Cl(C(6)H(6)N(2)O)], the Cu atom is coordinated by one neutral and one deprotonated pyridine-2-carboxaldehyde oxime (pco) ligand, resulting in the formation of two five-membered CuN(2)C(2) rings. Together with the additional coordinating chloride anion, the coordination polyhedron of copper is best described as a distorted square-pyramid, the distortion parameter being 0.288. The two organic ligands are linked by an intramolecular O-H⋯O hydrogen bond.

9.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 2): o397, 2008 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-21201425

RESUMO

The title compound, C(20)H(14)N(2)O(4)·H(2)O, was synthesized by the reaction of fluorescein and hydrazine hydrate in ethanol. In the crystal structure, the organic mol-ecules are linked into extended two-dimensional networks by inter-molecular hydrogen bonding. Additional face-to-face π-π stacking inter-actions between the phenolic benzene rings in two adjacent mol-ecules [centroid-to-centroid separation = 3.773 (3) Å] link the mol-ecules into a three-dimensional framework.

10.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 2): o442, 2008 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-21201469

RESUMO

The title compound, C(31)H(20)N(2)O(5)·C(2)H(3)N, was synthesized by the reaction of fluorescein hydrazide and excess 2-hydr-oxy-1-naphthaldehyde in acetonitrile. The spirolactam ring is planar and is nearly at right angles to the two benzene rings of the xanthene system. The dihedral angle between the two benzene rings of the xanthene system is 9.92 (4)°. In the crystal structure, the mol-ecules are linked into extended two-dimensional networks by inter-molecular hydrogen bonding. Acetonitrile mol-ecules are located in the voids between the two-dimensional networks.

11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(4): 913-6, 2008 Apr.
Artigo em Zh | MEDLINE | ID: mdl-18619328

RESUMO

The interaction between norfloxacin and bovine serum albumin, and the influence of Zinc (II) on the system of norfloxacin and bovine serum albumin was studied under physiological condition by fluorescence method. It was shown that norfloxacin has a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. The fluorescence quenching data were analyzed according to Stern-Volmer equation and double-reciprocal equation, and the binding constant (K) and the binding sites (n) were obtained. In the system of binary complex of NFLX and BSA, K = 6.80 x 10(5) and n = 1.21. There is a strong combination between NFLX and BSA, which offers the condition for the serum protein to be deposited and transported in vivo. Besides, the combination between NFLX and BSA becomes stronger in the presence of Zinc (II). According to Stern-Volmer equation and double-reciprocal equation, the concentration of Znic (II) is denser, and the binding constant (K) and the binding sites (n) are bigger. By studying the binding interaction between Zinc (II), norfloxacin and BSA, the mechanism of the interaction among norfloxacin, Zinc (II) and protein in organism, is furtherly discussed.


Assuntos
Soroalbumina Bovina/análise , Espectrometria de Fluorescência/métodos , Zinco/química , Animais , Bovinos , Norfloxacino/química , Soroalbumina Bovina/química
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(4): 765-8, 2007 Apr.
Artigo em Zh | MEDLINE | ID: mdl-17608194

RESUMO

The influences of fleroxacin (FLRX) on the fluorescence of bovine serum albumin(BSA), zinc(II) on that of bovine serum albumin, and zinc(II) on the of fleroxacin and bovine serum albumin were studied under imitated the physiological condition. It was shown that both fleroxacin and zinc(II) have a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. But the fluorescence quenching action of fleroxacin on BSA was much stronger in the presence of zinc (II). The fluorescence quenching data were analyzed according to Stern-Volmer equation and double-reciprocal equation, and the binding constant(K) and the binding sites(n) were obtained. In the system of binary complex of FLRX and BSA, K = 5.44 x 10(4) and n = 1.05, while in the system of binary complex of zinc(II) and BSA, K = 2.19 x 10(9) and n = 2.


Assuntos
Fleroxacino/química , Soroalbumina Bovina/análise , Espectrometria de Fluorescência/métodos , Zinco/química , Animais , Bovinos , Soroalbumina Bovina/química
13.
ACS Appl Mater Interfaces ; 8(48): 32862-32868, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27934148

RESUMO

We prepared a cost-effective, environmentally friendly carbonaceuous oil sorbent with a lotus effect structure using a simple one-pot hydrothermal reaction and a mild modification process. The carbonaceous oil sorbent can rapidly, efficiently, and continuously collect oil in situ from a water surface. This sorbent was unlike traditional sorbents because it was not dependent on the weight and volume of the sorption material. The sorbent was also successfully used to separate and collect crude oil from the water surface and can collect organic solvents underwater. This novel oil sorbent and oil-collection device can be used in case of emergency for organic solvent leakages, as well as leakages in tankers and offshore drilling platforms.

14.
Dalton Trans ; 45(20): 8347-54, 2016 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-26606324

RESUMO

A colorimetric assay is proposed for the selective detection of Cr(iii) and Cr(vi) via the aggregation-induced color change of gallic acid capped gold nanoparticles (GA-AuNPs). The AuNPs are characterized using UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier-transform infrared spectrometry (FT-IR). To detect Cr(iii) and Cr(vi) coexisting in a sample, citrate and thiosulfate were applied to mask Cr(vi) for the detection of Cr(iii), and ethylenediaminetetraacetic acid disodium salt (EDTA) was applied to mask Cr(iii) for the detection of Cr(vi). At optimized experimental conditions, the selectivity of these AuNPs-based detection systems is excellent for Cr(iii) and/or Cr(vi) compared with other types of metal ions. The limit of detections (LODs) of a mixture of Cr(iii) and Cr(vi), Cr(iii) and Cr(vi) by eye vision are 1.5, 1.5 and 2 µM, respectively, and those by UV-vis spectroscopy are 0.05, 0.1 and 0.1 µM, respectively. The minimum detectable concentrations for Cr(iii) or Cr(vi) are all below the guideline value set by the US Environmental Protection Agency (EPA). The applicability of the AuNPs-based colorimetric sensor is also validated by the detection of Cr(iii) and Cr(vi) in electroplating wastewater and real water samples with high recoveries.

15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 25(2): 246-8, 2005 Feb.
Artigo em Zh | MEDLINE | ID: mdl-15852867

RESUMO

The interaction of Pb2+ and bovine serum albumin (BSA) was studied under conditions similar to those in human bodies by fluorescence spectra. The results indicated that tryptophan and tyrosine, which were located in BSA, had a max fluorescence emission peak at 341 nm with an excitation wavelength of 283 nm. It was shown that Pb2+ had a powerful ability to quench the BSA fluorescence with a mechanism of a static process rather than a dynamic one. The apparent quenching constant Kq was obtained to be 9.5 x 10(12) L x mol(-1) x s(-1) by Stern-Volmer equation. The apparent complexation constant of Pb2 x BSA is lgK = 11.61. The nitrogen in BSA could coordinate with lead in Pb2-BSA.


Assuntos
Fluorescência , Chumbo/química , Soroalbumina Bovina/química , Espectrometria de Fluorescência/métodos , Algoritmos , Animais , Bovinos , Humanos , Cinética , Chumbo/metabolismo , Modelos Químicos , Ligação Proteica , Soroalbumina Bovina/metabolismo , Triptofano/química , Triptofano/metabolismo , Tirosina/química , Tirosina/metabolismo
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 23(3): 535-8, 2003 Jun.
Artigo em Zh | MEDLINE | ID: mdl-12953535

RESUMO

By means of artificial neural network and Levenberg-Marquardt back-propagation training algorithm, the three components of vitamin B1, B2, B6 were determined simultaneously, in which the spectra overlapped. In the range of 390-520 nm, the fluorescence intensities at 15 wavelengths were taken as a character of the artificial neural network, and samples were arranged by the method of equality design. The mean recoveries of vitamin B1, vitamin B2, and vitamin B6 were 99.86%, 99.60% and 99.49% respectively. The RSDs of the results were 1.7%, 1.6%, and 1.7%.


Assuntos
Riboflavina/análise , Tiamina/análise , Vitamina B 6/análise , Algoritmos , Redes Neurais de Computação , Espectrometria de Fluorescência
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 23(2): 318-21, 2003 Apr.
Artigo em Zh | MEDLINE | ID: mdl-12961882

RESUMO

A new fluorescence method by artificial neural network for the simultaneous determination of tryptophan and tyrosine was developed. The determination was carried out in the KH2PO4-K2HPO4 buffer solution (pH = 7.15) and at the EX (excitation) wavelength of 224 nm. In the range of 290-400 nm, the fluorescence intensities at fourteen wavelengths were taken as characteristic parameters of the artificial neural network, and the samples were arranged by the method of equality design. The mean recoveries of tryptophan and tyrosine were 100.9% and 101.6% respectively. The RSDs of the results were 4.18% and 4.17%. The method has been applied to the determination of tryptophan and tyrosine in compound amino acid injection, and the relative errors were 4.0% and 2.6%, respectively. The results were better than those of other networks in training speed and accuracy. In conclusion, the new network spectrofluorimetry is a good choice for multicomponent resolving analysis.


Assuntos
Triptofano/análise , Tirosina/análise , Aminoácidos/química , Injeções , Redes Neurais de Computação , Sensibilidade e Especificidade , Espectrometria de Fluorescência/métodos
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 22(5): 813-5, 2002 Oct.
Artigo em Zh | MEDLINE | ID: mdl-12938438

RESUMO

By the means of artificial neural network and Levenberg-Marquardt back-propagation train algorithm, the two components of phenol, resorcinol were determined simultaneously, in which the fluorescence spectra overlapped. In 290-345 nm, the fluorescence intensity at 14 wavelengths were taken as character of artificial neural network, and samples were arranged by method of equality design. The mean recovery of phenol and resorcinol were 100.2%, 99.99% respectively. The RSD of the results were 0.4% and 1.3%.


Assuntos
Redes Neurais de Computação , Fenol/análise , Resorcinóis/análise , Algoritmos , Espectrometria de Fluorescência/métodos
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 24(6): 730-2, 2004 Jun.
Artigo em Zh | MEDLINE | ID: mdl-15766195

RESUMO

A simultaneous catalytic effect copper (II) and iron (III) on the oxidation of acid chrome blue K by potassium bromate in dilute sulfuric acid medium was observed. But there was an obvious difference in their reaction rates, and the ratio of the reaction constant changed with time. And their spectral addiitive properties were not satisfactory. The simultaneous determination of copper and iron by catalytic kinetic spectrophotometric method was realized by using a three-layer Levenberg-Marquardt BP neural network to cope with the experimental data. The optimum conditions of reaction and determination were studied. The calculation results of the determination in synthetic samples and human hair were satisfactory.


Assuntos
Compostos Azo/química , Cobre/análise , Ferro/análise , Naftalenossulfonatos/química , Espectrofotometria/métodos , Ácidos Sulfúricos/química , Animais , Cabelo/química , Humanos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Redes Neurais de Computação , Oxirredução
20.
Dalton Trans ; 43(22): 8461-8, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24745033

RESUMO

SBA-15 functionalized with N-[3-(trimethoxysilyl)propyl]ethylene-diamine (TPED) was synthesized and used for the colorimetric detection of Cu(2+) and removal of heavy metal ions in aqueous solutions. Compared to free SBA-15, the adsorption ability of diamine-functionalized SBA-15 (depicted as SBA-TPED) increased remarkably, the maximum adsorption capacity of SBA-TPED for Cu(2+), Pb(2+) and Zn(2+) was 27.22, 96.43 and 12.16 mg g(-1), respectively. Furthermore, SBA-TPED exhibits high selectivity for Cu(2+) with the relative selectivity coefficient of SBA-TPED for Cu(2+)/Pb(2+) being over 10 and for Cu(2+)/Zn(2+) being over 60. The naked-eye detection limit of SBA-TPED for Cu(2+) is 0.95 ppm, and the determination of Cu(2+) in real water samples also displays satisfactory results. Moreover, SBA-TPED possesses fast kinetics for removing Cu(2+) with a saturation time of less than 30 min, and can be regenerated by simple acid treatment.

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