64 resultados para Scale [1:10,000,000].None


Relevância:

100.00% 100.00%

Publicador:

Resumo:

A surface-renewable tris (1,10-phenanthroline-5, 6-dione) iron (II) hexafluorophosphate (FePD) modified carbon ceramic electrode was constructed by dispersing FePD and graphite powder in methyltrimethoxysilane (MTMOS) based gels. The FePD-modified electrode presented pH dependent voltammetric behavior, and its peak currents were diffusion-controlled in 0.1 mol/L Na2SO4 + H2SO4 solution (pH = 0. 4). In the, presence of iodate, clear electrocatalytic reduction waves were observed and thus the chemically modified electrode was used as an amperometric sensor for iodate in common salt. The linear range, sensitivity, detection limit and response time of the iodate sensor were 5 x 10(-6)-1 x 10(-2) mol/L, 7.448 muA.L/mmol, 1.2 x 10(-6) mol/L and 5 s, respectively. A distinct advantage of this sensor is its good reproducibility of surface-renewal by simple mechanical polishing.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

分别合成了稀土(Eu3+和Tb3+)与柠檬酸、1,10 菲咯啉配位的稀土配合物。通过元素分析和红外分析确定了配合物的组成。通过荧光光谱与荧光寿命的测试,研究了它们的荧光性质。结果表明当铽掺入配合物后,铽能极大地增强铕的特征荧光,而铽的荧光被严重猝灭,其荧光强度以指数形式衰减。铕的荧光在铽荧光猝灭最严重时,被增强的效果最好,铕的荧光强度是荧光增强效果和铕的含量共同作用的结果,当铕与铽的浓度比为6∶4时能得到相应的铕的荧光最强的配合物。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The efficient synthesis of 5-(5-bromovaleramido)-1,10-phenanthroline, 5-(6-bromohexanamido)-1,10-phenanthroline, and 5-(11-bromoundecanamido)-1,10-phenanthroline are described, which reacted with cis-Ru(bpy)(2)Cl-2. 2H(2)O and sodium hexafluorophosphate to form Ru(bpy)(2)[phen-NHCO(CH2)(n)Br](PF6)(2) (n = 4, 5 or 10; phen = 1,10-phenanthroline). The intricate H-1 NMR spectra at low field of these complexes were completely assigned in virtue of H-1-H-1 COSY technique. Cyclic voltammetry was used to study electrochemical behaviours of these complexes, and their luminescent properties were investigated with fluorescent spectra.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present paper covers the syntheses of 1,8-adipoylamido-bis(1,10-phenanthroline-5-yl)(bphaa) and its binuclear complex {[(bpy)(2)Ru](2)(bphaa)} (PF6)(4), where bpy is 2,2'-bipyridine. The two novel compounds were confirmed by means of elemental analysis, IR, and LD-MS and H-1 NMR, and H-1 NMR spectra were completely assigned in virtue of H-1-H-1 COSY. chemical behavior of the binuclear Ru (I) complex was obtained using cyclic and voltammetry. Its photophysical property was investigated by electronic absorption, excitation and emission spectra.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The title two-dimensional coordination polymer was synthesised and characterised by X-ray diffraction analysis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Three new asymmetrical ruthenium (II) complexes: [Ru(phen)(2){phen-NHCO(CH2)(4)Br}](PF6)(2), [Ru(phen)(2){phen-NHCO(CH2)(5)Br}](PF6)(2) and [Ru(phen)(2){phen-NHCO(CH2)(10)Br}](PF6)(2) were synthesized, which were confirmed by the technique of FT-IR, H-1 NMR and ESI-MS. The electrochemical and fluorescent properties of three Ru (II) complexes were investigated with cyclic voltammetry and fluorometry.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Four novel screw-like Ru(II) complexes, tris(5-lauramide-1,10-phenanthroline)Ru(II) bishexafluorophosphate, tris(5-myristamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate, tris(5-palmitamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate and tris (5-stearamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate have been efficiently synthesized. They are confirmed by the techniques of IR, H-1 NMR, H-1-H-1 COSY and ES-MS. Also, their electrochemistry, fluorescence and electrochemiluminescence are reported.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Synthesis, IR spectra, UV-vis spectra and photophysical properties of Gd3+, Eu3+, Tb3+ complexes with 3,4-furandicarboxylic acid and 1,10-phenanthroline are reported. Intramolecular energy transfer process for these complexes is discussed in detail. It is found that the intramolecular energy transfer efficiency depends on the relative positions between the resonance energy levels of the central rare earth ions and the lowest triplet state energies of ligands.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In-situ synthesis of europium and terbium complexes with 1,10-phenanthroline (phen) in silica matrix by a two-step sol-gel process has been proposed. The formation of europium and terbium complexes with phen in sol-gel derived silica gel were confirmed by the luminescence excitation spectra. The silica gels that contain in-situ synthesized europium and terbium complex exhibit the characteristic emission bands of the rare earth ions. Furthermore. the rare earth ions present longer fluorescence lifetimes than the comparable pure complex powder and the complexes dissolved in ethanol solutions. The luminescence properties of the silica gels codoped with europium (or terbium) and phen were also investigated with respect to the gels doped with europium (or terbium). (C) 1999 Elsevier Science B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ternary complexes of europium and terbium with paraaminobenzoic acid and 1,10-phenanthroline (Eu(p-ABA)(3). phen . 2H(2)O and Tb(p-ABA)(3). phen . 2H(2)O, where p-HABA = paraaminobenzoic acid and phen = 1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The luminescence behavior of the complexes in silica gels was studied in comparison with the. corresponding solid-state complexes by means of emission, excitation spectra, and Lifetimes. Within the range of effective dopant concentrations, the luminescence intensities of rare-earth complexes in silica gel increase with the increasing of their dopant concentration. The lifetimes of rare-earth ions (Eu3+ and-Tb3+) in silica gel doped with europium and terbium complexes become longer than those in pure complexes. Very small amounts of rare-earth complexes doped in silica gel matrix can exhibit excellent luminescence properties, (C) 1998 Elsevier Science Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A series of binary and ternary rare earth (Gd, Eu, Tb) complexes with aromatic acids and 1,10-phenanthroline have been synthesized. The lowest triplet state energies of ligands have been obtained by measuring the phosphorescence spectra of binary gadolinium complexes. By comparing the phosphorescence spectra of binary complexes with those of ternary ones, it is found that there exists another intramolecular energy transfer process from the aromatic acids to 1,10-phenanthroline besides the intramolecular energy transfer process between the aromatic acids and the central rare earth ions. The intramolecular energy transfer efficiencies have been calculated by determining phosphorescence lifetimes of binary and ternary gadolinium complexes. The luminescence properties of corresponding europium and terbium complexes are in agreement with the prediction based on energy transfer mechanism. (C) 1998 Elsevier Science S.A. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Some novel binary and ternary complexes of rare earth ions (Gd, Eu, Tb) with N-phenyl-2-aminobenzoic acid and 1,10-phenanthroline were synthesized by homogenous precipitation and characterized by elemental analysis, IR spectra, UV/Vis spectra, and thermal analysis. The phosphorescence spectra and lifetimes of gadolinium complexes were measured, and the triplet state energies of N-phenyl-2-aminobenzoic acid and 1,10-phenanthroline as well as the energy transfer efficiencies between N-phenyl-2-aminobenzoic acid and 1,10-phenanthroline were determined. The photophysical properties such as luminescence and intramolecular energy transfer between the rare earth center ions and the ligands and between ligands are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Europium and terbium complexes with 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the complexes in silica gels was studied compared with the corresponding solid state complexes by means of emission, excitation spectra and lifetimes. (C) 1998 Published by Elsevier Science S.A. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A series of rare earth (Gd, Eu, Tb) complexes with different substituent group carboxylic acids (ortho-hydroxylbenzioc acid, ortho-aminobenzoic acid and ortho-methoxy benzoic acid) and 1,10-phenanthroline were synthesized. The spectroscopic studies of the photophysical properties such as luminescence properties, energy match and intramolecular energy transfer were carried out. The lowest triplet state energies of ligands and the intramolecular energy transfer efficiencies were determined with the measurement of low phosphorescence spectra and lifetimes of Gd complexes.