226 resultados para HYBRID MESONS
Resumo:
We construct a hybrid bilayer membrane (HBM) on a new substrate-carbon electrode. It is an extension of HBM based on other substrates. Primary alkylamine was chemically modified onto the surface of a carbon electrode by electrochemical scans; thus, a monolayer was formed on the electrode. Because the alkane chains section is toward the outside, a hydrophobic surface was constructed. Then a lipid monolayer was spread on the hydrophobic surface of the carbon electrode. The formed HBM was characterized by electrochemical and ATR-FT-IR methods. From ATR-FT-IR results, the lipid order parameter (S) of 0.73 was obtained. This kind of hybrid membrane has the advantages of a lipid/alkanethiol HBM. A potential application of this HBM as a biosensor (detecting K+) was given.
Resumo:
Two novel organic-inorganic hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br (1), Cl (2); o-phen = o-phenanthroline) have been synthesized hydrothermally and characterized structurally by elemental analyses, IR, ESR, XPS spectrum, TG analyses and single-crystal X-ray diffraction. Both title compounds exhibit novel one-dimensional chainlike copper halide scaffolding constructed by the unusual [Cu3X3] hexagon motifs by sharing opposite edges, where a single Cu site of each [Cu3X3] hexagon is chelated with N donors of o-phen group. To our knowledge, such basic o-phen-copper halide skeleton has not been reported hitherto. Moreover, TG analyses indicate that both title compounds possess high thermal stability.
Resumo:
A new compound, (C6H6N3)(7)((PMo12O40)-O-m)(PMo(v)Mo(11)(m)O40) (.) 2CH(3)CH(2)OH (.) 5H(2)O, was synthesized and characterized by means of elemental analyses, IR spectroscopy, H-1 NMR spectroscopy and single crystal X-ray diffraction. This is the first example of benzotriazole-polyoxometalates species. The compound crystallized in a triclinic space group P (1) over bar with a = 1. 8378 (4) nm. b = 1. 9078 (4) nm. c = 2.1037 (4) nm. alpha = 63.41 (3)degrees. beta = 64.31 (3)degrees. gamma = 68.38 (3)degrees. V = 5.803 (2) nm(3). Z = 2. R-1 = 0.0486, wR(2) = 0.1357. The X-ray crystallographic study showed that the crystal structure was constructed by electrostatic interactions and hydrogen bonds between dodecamolybdophosphorate anions and protonated benzotriazole cations. The electrochemical behavior and the reduction of nitrite and hydrogen peroxide clectrocatalyzed by the title compound were studied.
Resumo:
In this paper, silica-based transparent organic-inorganic hybrid materials were prepared via the sol-gel process. Tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) were used as the inorganic and organic precursors, respectively. The terbium complex, Tb(Tfacac)(3)phen (Tfacac = 1,1,1-trifluoroacetylacetone, phen = 1, 10-phenanthroline) was successfully doped into organically modified silicate (ormosil) matrix derived from TEOS and GPTMS, and the luminescent properties of the resultant ormosil composite phosphors [ormosil/Th(Tfacac)(3)phen] were investigated compared with those of the Tb(Tfacac)(3)phen incorporated into SiO2 derived from TEOS (labeled as silica/Tb(Tfacac)(3)phen). Both kinds of the materials show the characteristic green emission of Tb3+ ion. The luminescence behavior of the resultant composite products was dependent on the matrix composition. The optimized lanthanide complex concentration in the ormosil/Tb(Tfacac)(3)phen was increased compared with in silica/Tb(Tfacac)(3)phen. Furthermore, the lifetime of Tb3+ in Tb(Tfacac)(3)phen, silica/Tb(Tfacac)(3)phen and ormosil/Tb(Tfacac)(3)phen follows the sequence: onmosil/Tb(Tfacac)(3)phen>silica/Tb(Tfacac)(3)phen>pure Tb(Tfacac)(3)phen.
Resumo:
A novel hybrid photochromic composite film composed of Preyssler's heteropoly acid H-12[EuP5W30O110] (EuP5W30) and polyvinylpyrrolidone (PVP) was prepared by dip-coating method. Atomic force microscopy (AFM) was used to investigate the surface topography. The change of characteristic peak in the infrared spectra (IR) was investigated. The TG curve showed three steps of weight loss and approximately revealed the composition of the hybrid film. Ultraviolet-visible adsorption spectra (UV-VIS) and electron resonance spectrum (ESR) were used to investigate the photochromic behavior and mechanism of hybrid film. The photoluminescent behavior of the film at room temperature was investigated to show the characteristic Eu3+ emission pattern of D-5(o)-F-7(J). The occurrence of photoluminescent activity confirms the potential for creating luminescent thin film with polyoxometalates (POMs).
Resumo:
Through layer-by-layer method [tetrakis(N-methylpyridyl)porphyrinato] cobalt (CoTMPyP) and polyoxometalyte were alternately deposited on 4-aminobenzoic acid (4-ABA) modified glassy carbon electrode. The resulting organic-inorganic hybrid films were characterized by cyclic voltammetry (CV), UV/visible absorption spectroscopy, and atomic force microscopy (AFM). It was proved that the multilayer films are uniform and stable. CoTMPyP-containing multilayer films exhibit remarkable electrocatalytic activity for the reduction of O-2. Rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry confirm that P2W18/CoTMPyP multilayer films can catalyze the four-electron almost reduction of O-2 to water in pH > 4.0 buffer solution, while SiW12/CoTMPyP multilayer films catalyze about two-electron reduction of O-2 to H2O2 in pH 1 - 6 buffer solutions. The kinetic constants for O-2 reduction were comparatively investigated at P2W18/CoTMPyP and SiW12/CoTMPyP multilayer films electrodes.
Resumo:
Luminescent hybrid thin films consisting of terbium complex covalently bonded to a silica-based network have been obtained in situ via a sol-gel approach. A new monomer, N-(4-benzoic acid-yl), N'-(propylthiethoxysilyl)urea (PABI), has been synthesized by grafting isocyanatopropyltriethoxysilane (ICPTES) to p-aminobenzoic acid and characterized by H-1 NMR IR and MS, The monomer acts as a ligand for Tb3+ ion and as a sol-gel precursor. Band emission front Tb3+ ion due to an efficient ligand-to-metal energy transfer was observed by UV excitation. The decay curves of Tb3+ in the hybrid films were measured. The energy difference between the triplet state energy of PABI and the D-5(4) level of Tb3+ ion falls in the exciting range to sensitize Tb3+ ion fluorescence.
Resumo:
In situ synthesis of terbium carboxyl complexes in an organic-inorganic hybrid matrix by a sol-gel process has been proposed. The formation of terbium carboxyl complexes in the hybrid matrix is confirmed by the luminescence spectra and IR spectra. It is observed that the location at the amino group in aminobenzoic acid has a large effect on the luminescence properties and lifetimes. Furthermore, the emission intensity decreases with increasing temperature.
Resumo:
Hybrid materials, containing in-situ synthesized lanthanide complexes with intense green light, have been prepared via sol-gel process. The luminescence properties and the decay times of as-synthesized samples were investigated. The excitation spectrum of the samples indicates the formation of complexes between terbium (III) and P-Sulfosalicylic acid. The hybrid materials that contain in-situ synthesized terbium complexes exhibit the characteristic emission bands of the rare earth ions. In addition, the effect of concentration of terbium on the luminescence properties as well as the thermal stability were also studied.
Resumo:
New monomer N-(4-carboxyphenyl)-NL-(propyltriethoxysilyl)urea (1) which acts as both a ligand for Th3+ ion and a sol-gel precursor has been synthesized and characterized by H-1 NMR, and MS. Hybrid luminescent thin films consisting of organoterbium covalently bonded to a silica-based network have been obtained in situ via a sol-gel approach. Strong line emission of Tb3+ ion was observed from the hybrid luminescent films under UV excitation.
Resumo:
Novel hybrid thin films covalently doped with Eu3+ (Tb3+) have been prepared via direct routes involving co-condensation of tetraethoxysilane and phen-Si in the presence of Eu3+ (Tb3+) by spin-casting and their luminescence properties have been investigated in detail. Lanthanide ions can be sensitized by anchored phenanthroline in hybrid thin films. Excitation at the ligand absorption wavelength (272 nm) resulted in the strong emission of the lanthanide ions i.e. Eu3+ D-5(0)-F-7(J) (J=0, 1, 2, 3, 4) emission lines and Tb3+ D-5(4)-F-7(J) (J = 6, 5, 4, 3) due to the energy transfer from the ligands to the lanthanide ions.
Resumo:
A novel organic-inorganic hybrid complex [(CuCl)(2) (o-phen)](infinity) 1 (o-phen = o-phenanthroline) has been hydrothermally synthesized and structurally characterized by elemental analyses, XPS spectrum, TG analysis, and single-crystal X-ray diffraction. Compound I crystallizes in the monoclinic system, space group P2(1)/n, a = 3.7285(7) Angstrom, b = 19.603(4) Angstrom, c = 16.757(3) Angstrom, beta = 95.83(3)degrees, V = 1218.4(4) Angstrom(3), Z = 4, lambda(MoKalpha) = 0.71073 Angstrom (R(F) = 0.0643 for 2559 reflections). Data were collected on an R-axis RAPID diffractometer at 293 K in the range of 1.60 < θ < 27.48degrees. The title compound exhibits a one-dimensional chain-like scaffolding constructed by the unusual [Cu3Cl3] hexagon motifs by, sharing opposite edges. Only Cu(1) sites of the [Cu3Cl3] hexagon are coordinated with N donors of o-phen groups. Furthermore, the three-dimensional supermolecular architecture is formed by C-H...Cl hydrogen bonds between o-phen groups and CuCl chains.
Resumo:
A new kind of luminescent organic-inorganic hybrid material (denoted Hybrid I) consisting of europium 1,10-phenanthroline complexes covalently attached to a silica-based network was prepared by a sol-gel process. 1,10-Phenanthroline grafted to 3-(triethoxysilyl)propyl isocyanate was used as one of the precursors for the preparation of an organic-inorganic hybrid materials. For comparison purposes, the hybrid material (denoted Hybrid II) in which phenanthroline was not grafted onto the silica backbone of the frameworks was also prepared. Elemental analysis; NMR, FT-IR, UV/vis absorption, and luminescence spectroscopies, and luminescence decay analysis were used to characterize the obtained hybrid materials. It is shown that the homogeneity of Hybrid I is superior to that of Hybrid II, and a higher concentration europium can be incorporated into Hybrid I than Hybrid II. Excitation at the ligand absorption wavelength (283 nm) resulted in the strong emission of the Eu3+ D-5(0)-F-7(J) (J = 0-4) transition lines as a result of the efficient energy transfer from the ligands to the EU3+ in Hybrid I. The number of water molecules coordinated to the europium ion was estimated, and the structure of the as-synthesized Hybrid I was predicted on the basis of the experimental results.
Resumo:
An unusual composite hybrid material [Co-4 (phen)(8) (H2O)(2) (HPO3)(2)](H3O)(3) [PMo8VI V-4(IV) O-40 ((VO)-O-IV) 2] 1 (phen = 1,10-phenanthroline) has been hydrothermally synthesized from a mixture of NH4VO3, Na2MoO4.2H(2)O, CoCl2.6H(2)O, phen, H3PO3 and water. It was characterized by elemental analysis, IR, UV-vis, XPS, EPR, TG and single crystal X-ray diffraction. The title compound is constructed from the organic-inorganic hybrid [Co-4(phen)(8)(H2O)(2) (HPO3)(2)](4+) and highly reduced bi-capped pseudo-Keggin [(PMo8V4O40)-V-VI-O-IV ((VO)-O-IV)(2)](7-) polyoxoanions The structure exhibits an extended 2D network through hydrogen bonds among cations, anions and H2O, combining polyoxometalates with metal phosphonates for the first time.
Resumo:
Organic-inorganic hybrid SiO2 xerogels were prepared by the sol-gel method under various preparation conditions and compositions by using tetraethoxysilane (TEOS), (3-aminopropyl) triethoxysilane (A-PS), (3-glycidoxypropyl) trimethoxysilane (GPS), organic acid (CH3COOH) and inorganic acids (HCl, HNO3, H2SO4) as the main precursors. Luminescence and FT-IR spectra were used to characterize the resulted hybrid SiO2 xerogels. The result of FT-IR spectrum shows that the xerogels are composed of non-crystalline -Si-O-Si- networks containing some organic groups such as -NH, -CH and -OH. Under the excitation of 365 nm, all the hybrid xerogels exhibit strong luminescence in the blue region, but the emission intensity and position depend on the starting precursor compositions to a large extent. Suitable amount of polyethylene glycol (PEG500 and PEG10000) in the hybrid xerogels can enhance the emission intensity. Additionally, the emission intensity of the hybrid xerogels increases with heat treatment temperature in the range of ambient to 200degreesC, and vacuum condition is also able to enhance the emission intensity.