357 resultados para X-ray photoelectron microscopy


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The binuclear complex [Ni(oxae)Ni(phen)2](ClO4)(2) . H2O (oxae=N,N'bis(2-aminoethyl) oxamido dianion, phen = 1, 10-phenanthroline) was prepared from the planar monomeric complex Ni(oxae) and characterized through analytical and spectroscopic measurements. The structure of [Ni(oxae)Ni(phen)(2)] (ClO4)2 . 3H(2)O was investigated by single-crystal X-ray analysis. The complex has an extended oxamido-bridged structure and consists of two nickel(II) ions, one of them in a square planar environment and another in a distorted octahedral environment. The Ni-Ni distance is 5.267 Angstrom.

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The interaction of [(C(5)H(4)R)(2)NdCl.2LiCl] (R = H, Bu(t)) with one equivalent of Li[(CH2)(CH2)PPh(2)] in refluxing tetrahydrofuran gave the purplish-blue complex [(C(5)H(4)R)(3)NdCH2P(Me)Ph(2)] in 50% yield. The compounds have been fully characterized by analytical, spectroscopic and X-ray diffraction methods. Variable temperature P-31{H-1} NMR spectroscopy indicated the existence of the following equilibrium: [(C(5)H(4)R)(3)NdCH2P(Me)Ph(2)] + THF reversible arrow (C(5)H(4)R)(3)Nd(THF) + CH2=P(Me)Ph(2). At room temperature, the exchange between the coordinated and free ylide ligand is slow on the NMR time scale.

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LaCl3.2LiCl reacts with two equivalents of Bu(t)CpNa in THF to give the complex [(Bu(t)Cp)3LaClLi(THF)3]. The crystal structure was determined by X-ray diffraction at room temperature. Two units, (Bu(t)Cp)3La and Li(THF)3, are connected by a single chlo

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The interface thickness in two triblock copolymers were determined using small-angle x-ray scattering in the context of the theory proposed by Ruland. The thickness was found to be nonexistent for the samples at three different temperatures. By viewing th

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A series of neutral eta6-C6Me6 complexes of lanthanide elements Ln(176-C6Me6)(AlCl4)3 . MeC6H5(Ln = Nd, Sm, Gd, Yb) has been prepared directly in good yields from the reaction of LnCl3, AlCl3 and C6Me6 in toluene. The complexes have been characte

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A novel framework material, Zn-2(HPO4)(3).H3NCH2CH2NH3, has been synthesised and its crystal structure determined by single crystal X-ray diffraction.

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1:12 phosphomolybdic anion doped polypyrrole film electrode was characterized by in-situ UV-vis spectroelectrochemistry, X-ray photoelectron spectroscopy(XPS), scan electronic microscopy(SEM) and electron spin resonance(ESR) spectroscopy.

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The interaction of (C5H5)2SmCl.LiCl with one equivalent of Li[(CH2)(CH2) PPh2] in refluxing tetrahydrofuran gives the yellow complex [(C5H5)3SmCH2P (Me)Ph2] in 30% yield. The compound has been fully characterized by analytical, spectroscopic and X-ray diffraction methods.

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[Cp3Yb] reacts with HOR (Cp = C5H5; R = CH2CH=CH2, CH2CH2Me) in thf (thf = tetrahydrofuran)at room temperature to give complexes [{Cp2Yb(mu-OR)}2], which are dehydrogenated to yield the new complex [{Cp2Yb(mu-OCH=C=CH2)}2] in refluxing thf solution; the X-ray crystal structure shows that the new complex is dimeric with oxygen atoms as bridging groups.

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X-ray photoelectron spectra of the bioinorganic complexes of Na and La with N-acetylalanine and N-acetylvaline have been measured. It has been found that the spectra of the O 1s core level in the complexes of Na with these amino acids are very different from those in the complexes of La with the same amino acids. The results indicate that in the complexes of La with N-acetylalanine and N-acetylvaline, both the oxygen atoms from the carboxyl group and the oxygen atoms from the carbonyl group of the amino acids will directly coordinate to the La ion, whereas only the oxygen atoms from the carboxyl group of the amino acids can directly coordinate to the Na ion in the complexes of Na with N-acetylalanine and N-acetylvaline.

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X-ray photoelectron spectra of some bioinorganic complexes of La, Pr, Nd, Sm, and Gd with N-acetylvaline have-been measured. The complex formation does not give any detectable influence on the binding energy of the N 1s peak in the amino group, but has some appreciable effect on the binding energy of the C 1s peak and the O 1s peak in the carboxyl and carbonyl group of the biological ligand. The spin-orbit splitting between the 3d5/2 and 3d3/2 core level of the rare earth ion in these bioinorganic complexes also becomes slightly larger than that of the free rare earth atom due to the effect of the crystal field from the biological ligands.

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The utility of the high-temperature superconductor, YBa2Cu3O7-x as the cathode material for an all-solid-state lithium cell has been examined. The capacity of YBa2Cu3O7-x is 223 mA h g-1 and the discharge efficiency is > 92%. Measurements of a.c. impedance show that the charge-transfer resistance at the interface of the electrolyte/cathode is very low and increases with the depth-of-discharge of the battery. Studies using X-ray photoelectron spectroscopy (XPS) reveal that the cathode becomes doped with Li+ ions as the cell discharges.

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Reaction of lanthanide trichlorides with two equivalents of sodium t-butylcyclopentadienide in THF gave rise to the bis(t-butylcyclopentadienyl)lanthanide chloride complexes [(Bu(t)Cp)2LnCl]2 (Ln = Pr, Gd, Er), which were characterized by elemental analysis, IR and H-1 NMR spectroscopy. In addition, the crystal structures of [(ButCp)2PrCl]2 (1) and [(ButCp)2GdCl]2 (2) were determined by single crystal X-ray diffraction at room temperature. The coordination number for Pr3+ and Gd3+ is 8 and the bond lengths Pr-Cl and Gd-Cl are 2.864(2) and 2.771(3) angstrom, respectively. The structural studies showed the complexes to have C2h symmetry.

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(ButCp)2NdCl.2THF reacts with one equivalent of phenyllithum in THF yielding tris(tert-butylcyclopentadienyl)neodymium lithium bromide tetrahydrofuran, [(ButCP)3 NdBrLi(THF)3], as a by-product, whose structure has been determined by X-ray crystallography. The 10-coordinated neodymium atom is bonded to three tert-butyl-cyclopentadienyl groups and one bromine atom, forming a distorted pseudo-tetrahedron.

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New bis (2-methoxyethylcyclopentadienyl) yttrium and ytterbium tetrahydroborates (Ln = Y, 1; Yb, 2) have been synthesized in good yield by the reaction of bis (2-methoxyethylcyclopentadienyl) lanthanide chlorides (Ln = Y, Yb) with sodium borohydride in THF at room temperature. The title complexes were characterized by elemental analyses, MS, H-1 NMR and IR spectra. The crystal structures of 1 and 2 have been determined by X-ray diffraction. 1 crystallizes from THF-n-Hexane in space group Pna2(1) with unit cell parametert: a = 1.2390(3), b = 1.1339(2), c = 1.1919 (2) nm and V = 1.6745(6) nm3 with z = 4 for D(c) = 1.39 g.cm-3.The structure was solved by direct method and refined to final R = 0.061 (for 1730 observed reflections). The Space group of 2 is Pna2(1) with unit cell parameters: a = 1.2399(6), b = 1.1371(5), c = 1.1897(2) nm and V = 1.6773(1) nm3 with z = 4 for D(c) = 1.72 g.cm-3, R = 0.038 (for 2157 observed reflections). The X ray structures and IR reveal the bidentate yttrium and ytterbium tetrahydroborate complexes with the intramolecular coordination bonds between lanthanide metal and ligand oxygen atoms.