995 resultados para luminescenza complessi Ir(III) anioni soft salts
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Aprende a leer es un sistema de fichas de iniciación a la lectura, especialmente confeccionado para niños de Educación Infantil, alumnos lentos o con dificultades para la lectura y fundamentalmente para alumnos deficientes integrados en aulas de Primaria o Educación Especial. Aporta al profesorado una metodología sencilla y útil aplicación, tanto para el grupo clase como reducido o individual. Este método o sistema está estructurado en tres niveles que se han plasmado en tres cuadernos: en el primer nivel o cuaderno el alumno discriminará auditiva y visualmente todos los fonemas de nuestra lengua comenzando por la identificación visual de una letra entre varias, se pasa a continuación a la localización de la misma entre imágenes para terminar con la diferenciación auditiva de ésta estimulándose mediante gráficos o dibujos. Tras el aprendizaje de cada cinco fonemas se incluyen dos o tres fichas de repaso y refuerzo con objeto de asegurar la adquisición de los mismos. Este proceso se continuará hasta el último fonema con el cual se da fin a este primer cuaderno. En el segundo nivel, el alumno proseguirá con el aprendizaje de las letras en palabras pasando más adelante al conocimiento detallado de cada una de las sílabas y a su posterior lectura. En el Nivel III, el del presente libro, se entra de lleno en la palabra, y en lenta progresión, evitando dejar lagunas que posteriormente podrían dar pie a estancamientos o retrocesos en el aprendizaje, se llega a la lectura de oraciones o frases con el cual se deja al alumno preparado para los distintos estudios que poco a poco habrá de ir afrontando.
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Transcripción de la primera Encíclica publicada por S. S. Pablo VI, 'Ecclesiam Suam', en el año 1964, basada en una doctrina de comprensión y concordia frente al mundo moderno, el 'mandato' de la Iglesia en el mundo contemporáneo. Consta de varias partes: I. La Conciencia de la Iglesia. II. La Renovación de la Iglesia. III. Diálogo de la Iglesia con el mundo.
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New tri-functional ligands of the type R2NCCCH2SCH2CCNR2 (where R = iso-propyl, n-butyl or iso-butyl) were prepared and characterized. The coordination chemistry of these ligands with uranyl and lanthanum(III) nitrates was studied by using the IR, (HNMR)-H-1 and elemental analysis methods. Structures for the compounds [UO2(NO3)(2)((Pr2NCOCH2SCH2CONPr2)-Pr-i-Pr-i)] [UO2(NO3)(2)((Bu2NCOCH2SCH2CONBu2)-Bu-i-Bu-i)(2)] [La(NO3)(3)((Pr2NCOCH2SCH2CONPr2)-Pr-i-Pr-i)(2)] and [La(NO3)(3)((Bu2NCOCH2SCH2CONBu2)-Bu-i-Bu-i)(2)] were determined by single crystal X-ray diffraction. These structures show that the ligand acts as a bidentate chelating ligand and bonds through both the carbamoyl groups to the uranyl and lanthanum(III) nitrate groups. Solvent extraction studies show that the ligand can extract the uranyl ion from the nitric acid medium but does not show any ability to extract the americium (III) ion. (C) 2009 Elsevier Ltd. All rights reserved.
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Using the 1: 2 condensate of benzildihydrazone and 2-acetylpyridine as a tetradentate N donor ligand L, LaL(NO3)(3) (1) and EuL(NO3)(3) (2), which are pale yellow in colour, are synthesized. While single crystals of 1 could not be obtained, 2 crystallises as a monodichloromethane solvate, 2 center dot CH2Cl2 in the space group Cc with a = 11.7099(5) angstrom, b = 16.4872(5) angstrom, c = 17.9224(6) angstrom and beta = 104.048(4)degrees. From the X-ray crystal structure, 2 is found to be a rare example of monohelical complex of Eu(III). Complex 1 is diamagnetic. The magnetic moment of 2 at room temperature is 3.32 BM. Comparing the FT-IR spectra of 1 and 2, it is concluded that 1 also is a mononuclear single helix. H-1 NMR reveals that both 1 and 2 are mixtures of two diastereomers. In the case of the La(III) complex (1), the diastereomeric excess is only 10% but in the Eu(III) complex 2 it is 80%. The occurrence of diastereomerism is explained by the chiralities of the helical motif and the type of pentakis chelates present in 1 and 2.
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Two new complex salts of the form (Bu4N)(2)[Ni(L)(2)] (1) and (Ph4P)(2)[Ni(L)(2)] (2) and four heteroleptic complexes cis-M(PPh3)(2)(L) [M = Ni(II) (3), Pd(II) (4), L = 4-CH3OC6H4SO2N=CS2] and cis-M(PPh3)(2)(L') [M = Pd(II) (5), Pt(II) (6), L' = C6H5SO2N=CS2] were prepared and characterized by elemental analyses, IR, H-1, C-13 and P-31 NMR and UV-Vis spectra, solution and solid phase conductivity measurements and X-ray crystallography. A minor product trans-Pd(PPh3)(2)(SH)(2), 4a was also obtained with the synthesis of 4. The NiS4 and MP2S2 core in the complex salts and heteroleptic complexes are in the distorted square-plane whereas in the trans complex, 4a the centrosymmetric PdS2P2 core is perforce square planar. X-ray crystallography revealed the proximity of the ortho phenyl proton of the PPh3 ligand to Pd(II) showing rare intramolecular C-H center dot center dot center dot Pd anagostic binding interactions in the palladium cis-5 and trans-4a complexes. The complex salts with sigma(rt) values similar to 10 (5) S cm (1) show semi-conductor behaviors. The palladium and platinum complexes show photoluminescence properties in solution at room temperature.
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The reaction of the fulvalene titanium(III) hydride [{Ti(η5-C5H5)(μ-H)}2(μ-η5-η5-C10H8)] (1) with chlorine leads to [{Ti(η5-C5H5)(μ-Cl)}2(μ-η5-η5-C10H8)] (3) and [{Ti(η5-C5H5)Cl2}2(μ-η5-η5-C10H8)] (4). The reaction of 3 with azobenzene, in wet toluene, gives [{Ti(η5-C5H5)Cl}2(μ-O)(μ-η5-η5-C10H8)] (5) and 1,2-diphenyl hydrazine. The alkylation of 4 and the analogous zirconium complex [{Zr(η5-C5H55)Cl2}2(μ-η5-η5-C10H8)] (2) with LiCH2SiMe3 or LiCH3 permits isolation of the tetraalkyl derivatives [{M(η5-C5H5)(CH2SiMe3)2}2(μ-η5-η5-C10H8)] (M Ti (6); Zr (8)) and [{Ti(η5-C5H5)(CH3)2}2(μ-η5-η5C10H8)] (7). All the new fulvalene compounds were characterized by IR, and 1H and 13C NMR spectroscope, and mass spectra and 5 by X-ray diffraction. The structure of 5 is very similar to that of the comparable TiIV compound [{Ti(η5-C5H5)2Cl}2(μ-O)] except for the smaller TiOTi angle (159.4° against 173.81°) and a significant deviation from linearity.
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New monometallic complex salts of the form X-2[M(L)(2)] [M = Ni2+, X = (CH3)(2)NH2+(1); M = Ni2+, X = (CH3)(4)N+ (2); M = Ni2+, X = (C2H5)(4)N+(3); M = Ni2+, X = (C3H7)(4)N+(4); M = Ni2+; X = (C6H13)(4)N+) (5); M = Pd2+,X = (CH3)(2)NH2+(6); M = Pd2+, X= (C2H5)(4)N+(7); M = Pd2+, X= (C3H7)(4)N+(8); M = Pd2+, X = (C6H13)(4)N+ (9); M = Pt2+, X = (CH3)(2)NH2+(10); L = p-tolylsulfonyldithiocarbimate (CH3C6H4SO2N=CS22 )] have been prepared and characterized by elemental analysis, IR, H-1 and C-13 NMR and UV-Vis spectroscopy; 1, 3, 4 and 5 by X-ray crystallography. In 1, 3, 4 and 5, the Ni atom is four coordinate with a square planar environment being bonded to four sulfur atoms from two bidentate ligands. All the salts are weakly conducting (sigma(rt) = 10 (7) to 10 (14) Scm (1)) because of the lack of significant S center dot center dot center dot S intermolecular interactions between complex anions [M(L)(2)](2) in the solid state however, they show behavior of semiconductors in the temperature range 353-453 K. All the Pd(II) and Pt(II) salts exhibited phtotolumeniscent emissions near visible region in solution at room temperature.
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A set of backbone modified peptides of general formula Boc-Xx-m-ABA-Yy-OMe where m-ABA is meta-aminobenzoic acid and Xx and Yy are natural amino acids such as Phe, Gly, Pro, Leu, Ile, Tyr and Trp etc., are found to self-assemble into soft nanovesicular structures in methanol-water solution (9:1 by v/v). At higher concentration the peptides generate larger vesicles which are formed through fusion of smaller vesicles. The formation of vesicles has been facilitated through the participation of various noncovalent interactions such as aromatic pi-stacking, hydrogen bonding and hydrophobic interactions. Model study indicates that the pi-stacking induced self-assembly, mediated by m-ABA is essential for well structured vesicles formation. The presence of conformationally rigid m-ABA in the backbone of the peptides also helps to form vesicular structures by restricting the conformational entropy. The vesicular structures get disrupted in presence of various salts such as KCl, CaCl(2), N(n-Bu)(4)Br and (NH(4))(2)SO(4) in methanol-water solution. Fluorescence microscopy and UV studies reveal that the soft nanovesicles encapsulate organic dye molecules such as Rhodamine B and Acridine Orange which could be released through salts induced disruption of vesicles.
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The chemistry of Ru(III) complexes containing dmso as a ligand has become an interesting area in the cancer treatment field. Because of this, structural knowledge and chemistry of the moiety Ru(III)-dmso have become important to cancer research. The crystal structures of the compounds mer-[RuCl(3)(dms)(3)] (1) and mer-[RuCl(3)(dms)(2)(dmso)]:mer-[RuCl(3)(dms)(3)] (2) were determined by X-ray crystallography and a speciation of the presence of intramolecular hydrogen bond in these structures has been studied. Compound (1) crystallizes in the orthorhombic space group, Pna2(1); a = 16.591(8) angstrom, b = 8.724(2) angstrom. c = 10.547(3) angstrom; Z = 12 and (2) crystallizes in the space group, P2(1)/C: a = 11.9930(2) angstrom, b = 7.9390(2) angstrom, c = 15.8700(3) angstrom, beta = 93.266(1)degrees, Z = 2. From the X-ray structures solved in this work, were possible to suggest an interpretation for the broad lines observed in the EPR spectra of the Ru(III) compounds explored here. Also, the exchange interactions detected by EPR spectroscopy in solid state and in solution, confirm the presence of van der Waals interactions such as C-H center dot center dot center dot Cl in the compounds (1), (2) and (3). The use of techniques such as IR, UV-vis, (1)H NMR and EPR Spectroscopy and Cyclic Voltammetry were applied in this work to analyze the behavior of these metallocompounds. (c) 2008 Elsevier B.V. All rights reserved.
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The reaction of dimethylthallium(III) hydroxide with picolinic acid (Hpic), 3-hydroxypicolinic acid (H(2)3hpic) and 6-hydroxypicolinic acid (H(2)6hpic) in an aqueous/methanol mixture afforded the complexes [TlMe(2)(pic)] (1), [TlMe(2)(H3hpic)] (2) and [TlMe(2)(H6hpic)] (3), respectively. Complex 3`, [NaTlMe(2)(6hpic)(2)](n), was obtained as a minor product from a methanolic solution of 3. Compounds 1-3 were characterized by IR and Raman spectroscopy and, in the cases of 1, 2 and Y, by single-crystal X-ray diffraction. Complex 3` is the first example of an H6hpic(-) heterobimetallic compound to be isolated. The (1)H and (13)C NMR spectra of 1 and 2 are also discussed. (c) 2008 Elsevier Ltd. All rights reserved.
Spectroscopic investigation of the interactions between emeraldine base polyaniline and Eu(III) ions
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The interactions of emeraldine base form of polyaniline (EB-PANI) and Eu(III) ions in 1-methyl-2-pyrrolidinone (NMP) solution and in films have been investigated by UV-vis-NIR, resonance Raman. luminescence and electron paramagnetic resonance (EPR) spectroscopies. These spectroscopic techniques allowed to characterize quinone and semiquinone segments in the polymeric chains. and the oxidation state of europium ions in Eu-PANI samples. For high values of Eu(III)/N molar ratio (24/1) the presence of a weak polaronic absorption band at 980 nm in UV-vis-NIR spectrum and the observation of bands at 1330 and 1378 (nu(center dot)(C-N+)) cm(-1) due to emeraldine salt in the Raman spectrum at 1064 nm indicate a low doping degree. Oxidation of EB-PANI to pernigraniline base (PB-PANI) occurs in diluted solutions. The experimental data showed that the solvent plays an important role on the nature of formed species. The narrow EPR signal at g = 2.006 (line width 8G) confirms the presence of PANI radical cations in Eu-PANI film. The absence of broad signal characteristic of Eu(II) in EPR spectrum suggested that europium ions are primarily at Eu(III) oxidation state. The luminescence spectra of Eu-PANI film presented emission bands at 405 and 418 nm assigned to PANI moieties and bands at 594,615 and 701 nm assigned to (5)D(0) -> (7)F(J) (J = 1, 2 and 4, respectively) transitions of Eu(III). EPR and photoluminescence data confirm that europium ions are mainly in Eu(III) oxidation state in Eu(III)/PANI films. (C) 2008 Elsevier B.V. All rights reserved.
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The products formed from the reaction of emeraldine base polyaniline (EB-PANI) with Fe(III) ions in N-methyl-pyrrolidone (NMP), dimethylacetamide (DMA), dimethylformamide (DMF) and m-cresol media have been investigated using UV-VIS-NIR and resonance Raman (lambda(0) = 632.8 and 1064 nm) spectroscopies. Through these results it was verified that the different PANI forms in solution can be formed by the suitable choice of the solvent. The behavior of Fe(III)/EB-PANI in different solvents was rationalized in terms of the interactions among Fe(III) ions, EB-PANI and solvent. In basic NMP, DMA and DMF media, the reaction of Fe(III) with EB-PANI yields EB-PANI doping giving ES-PANI and/or the EB-PANI oxidation to PB-PANI. The formation of ES-PANI is favored in DMF while PB-PANI is formed in a greater extension in NMP and DMA. In acidic m-cresol, only ES-PANI is produced in Fe(III)/EB-PANI solutions indicating the important role played by the solvent in the nature of the product. (C) 2010 Elsevier B.V. All rights reserved.
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The influence of molecular oxygen in the interactions of emeraldine base form of polyaniline (EB-PANI) with Fe(III) or Cu(II) ions in 1-methyl-2-pyrrolidinone (NMP) solutions has been investigated by UV-vis-NIR, resonance Raman and electron paramagnetic resonance (EPR) spectroscopies. Through the set of spectroscopic results it was possible to rationalize the role Of O(2) and to construct a scheme of preferential routes occurring in the interaction of EB-PANI with Fe(III) or Cu(II). Solutions of 4.0 mmol L(-1) EB-PANI with 0.8, 2.0 and 20 mmol L(-1) Fe(III) or Cu(II) ions in NMP were investigated and the main observed reactions were EB-PANI oxidation to pernigraniline (PB-PANI) and EB-PANI doping process by pseudo-protonation, or by a two-step redox process. In the presence Of O(2), PB-PANI is observed in all Fe(III)/EB solutions and EB-PANI doping only occurs in solutions with high Fe(III) concentrations through pseudo-protonation. On the other hand, emeraldine salt (ES-PANI) is formed in all Fe(III)/EB solutions under N(2) atmosphere and, in this case, doping occurs both by the pseudo-protonation and two-step redox mechanisms. In all Cu(II)/EB solutions PB-PANI is formed both in the presence and absence of O(2), and only for solutions with high Cu(II) concentrations doping process occurs in a very low degree. The most important result from EPR spectra was providing evidence for redox steps. The determined Cu(II) signal areas under oxygen are higher than under N(2) and, further. the initial metal proportions (1:2:20) are maintained in these spectra, indicating that Cu(I) formed are re-oxidized by O(2) and. so, Cu(II) ions are being recycled. Consistently, for the solutions prepared under nitrogen, the corresponding areas and proportions in the spectra are much lower, confirming that a partial reduction of Cu(II) ions actually occurs. (C) 2009 Elsevier B.V. All rights reserved.
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The anchoring of K[Ru-III(edta)(Cl)] on poly(amidoamine) dendrimers (PAMAM of three generations G(x)/Ru (x = 0, 2 and 3)) through a peptide type bond yielded the aquo species, [Ru-III(edta)(H2O)] on dendrimer surface, and upon NO exposure, yielded their nitrosyl analogues, Gx/RuNO. Characterization of these compounds by elemental analysis, and a UV-vis, IR and C-13 NMR spectroscopies indicated the immobilization of 4,12 and 29 molecules of [Ru-III(edta)(H2O)](-) or of the nitrosyl complex [Ru(II)edta)NO] on the dendrimer surface for G(X) = 0, 2 and 3, respectively. For each complex the electrochemical spectrum presented only one redox process with redox potential values of -0.20 and -0.32 V(vs SCE) attributed to the Ru/Run and NO+/NO0 couples in G(x)/Ru and G./RuNO, respectively. The one-electron reduction of Gx/RuNO` generates Gx/RuNOo, which undergoes aquation with a k(-NO) of 2.1 +/- 0.7 x 10(-3) s(-1) (pH 1.0, mu = 0.2 mol/L, CF3COOH/NaCF3COO, 25 degrees C). The Gx/RuNO species induced a relaxing effect in aortic rings denuded of endothelium and exhibited in vitro assay trypanocidal activity. (c) 2008 Elsevier Inc. All rights reserved.
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The present work was to carry out a study on the adsorption of hydrogen sulfide (H2S) in arrays synthesized from a commercial clay mineral formed by a mixture of dolomite and quartz. To produce the ion exchange matrix were made using aqueous solutions of salts of cobalt II chloride hexahydrate (CoCl2.6H2O) II cadmium nitrate tetrahydrate (Cd (NO3)2.4H2O) I mercuric chloride (HgCl) nitrate and chromium III pentahydrate (Cr (NO3)3.5H2O). The arrays were subjected to hydrogen sulphide gas passage for one hour. To check the amount of gas adsorbed was used gravimetric process. The best result was in the adsorption matrix doped with cadmium and the solution retained for a longer time than the largest amount of H2S was the cobalt matrix. The matrix unmodified exhibited poor adsorption capacity. The characterization of the matrices were used XRD, XRF and IV. Mother with cadmium showed a high capacity in ion exchange, because the percentage of cadmium increased from 0% to 81.38% by replacing atoms of calcium and silicon which increased from 96.54% to 17.56% and 15, 72% to 0.32%, respectively, but also the best performance in adsorption of H2S adsorbing 11.89507 mg per gram of matrix