Palladium(II) Complexes with Thiosemicarbazones. Syntheses, Characterization and Cytotoxicity against Breast Cancer Cells and Anti-Mycobacterium tuberculosis Activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Electro-precipitation of Fe(3)O(4) nanoparticles in ethanol

The preparation of superparamagnetic magnetite (Fe(3)O(4)) nanoparticles by electro-precipitation in ethanol is proposed. Particle average size can be set from 4.4 to 9 nm with a standard deviation around 20%. Combination of wide-angle X-ray scattering (WAXS), Electron energy loss spectroscopy (EELS) and Mossbauer spectroscopy characterizations clearly identifies the particles as magnetite single-crystals (Fe(3)O(4)). (C) 2008 Elsevier B.V. All rights reserved.

Hydrothermal treatment of gadolinium oxide in presence of silica

Hydrothermal and solvothermal (isopropanol) treatments of gadolinium oxide and silica were investigated under different pressure and temperature conditions. Products were examined by infrared vibrational spectroscopy (IR), x-ray powder diffraction (XRD) and thermal analysis (DTA, TG). Hexagonal gadolinium hydroxide was obtained in hydrothermal conditions, even in presence of silica, while no change was observed from isopropanolic medium treatment. Hydrothermally treated samples are more reactive as precursors for solid state reactions in inorganic synthesis.

Absorption and fluorescence of Er3+-doped LiYF4: Measurements and simulation

Er3+:LiYF4 single crystal has been studied by absorption and fluorescence spectroscopy in the IR-visible-UV (0-44000 cm-1) region from 4.2 K to room temperature. Polarized spectra were recorded in order to assign numerous Stark levels of electronic transitions mentioned but not attributed before in the related literature and to discuss the irreducible representations (irreps) of the 4I15/2 sublevels. A parametric hamiltonian, including free ion (Eν, α, β, γ, Tλ, ζ, Mk and Pi) and crystal field parameters (B2 0, B4 0, B4 4, B6 0 and B6 4) in an approximate D2d symmetry for the rare earth site in this scheelite type structure, was used to simulate 109 energy positions of the Er ion with a r.m.s. standard deviation of 14.6 cm-1. A comparison with previously published results for Nd3+ in the same matrix is done. © 1998 Elsevier Science S.A.

Study of KCl + x% in and KCl + y% TlCl thin films

The present work reports the study of KCl thin films doped with In+ or Tl+. Both systems show optical absorption bands similar to single crystals. As the impurity concentration increases, so does the absorption as also the half band width, unlike in KCl: Cu+ films. Further experimental techniques such as X-ray diffraction, scanning electron micrographs and energy dispersive X-ray observations were used and comparative analysis with KCl : Cu+ films reveals new conditions for better crystallinity of the samples.

Crystallization and preliminary X-ray analysis of SIII-SPIII, a ahospholipase A2 isolated from the venom of Bothrops jararacussu

Large single crystals have been obtained of SIII-SPIII, a phospholipase A2 from the venom of Bothrops jararacussu. The crystals belong to the orthorhombic system space group C222, and diffract X-rays to a resolution of 1.9 Å. Preliminary analysis reveals the presence of one molecule in the crystallographic asymmetric unit. The crystal structure is currently being determined using molecular replacement techniques.

Improved Conductivity Induced by Photodesorption in SnO2 Thin Films Grown by a Sol-Gel Dip Coating Technique

Thin films of undoped and Sb-doped SnO2 have been prepared by a sol-gel dip-coating technique. For the high doping level (2-3 mol% Sb) n-type degenerate conduction is expected, however, measurements of resistance as a function of temperature show that doped samples exhibit strong electron trapping, with capture levels at 39 and 81 meV. Heating in a vacuum and irradiation with UV monochromatic light (305 nm) improve the electrical characteristics, decreasing the carrier capture at low temperature. This suggests an oxygen related level, which can be eliminated by a photodesorption process. Absorption spectral dependence indicates an indirect bandgap transition with Eg ≅ 3.5 eV. Current-voltage characteristics indicate a thermionic emission mechanism through interfacial states.

Crystallographic and spectroscopic studies on palladium(II) complexes containing pyrazole and thiocyanate ligands

Mononuclear palladium(II) complexes containing both pyrazole-type ligands and thiocyanate, of general formula [Pd(SCN) 2(L) 2] {L = pyrazole (HPz) and l-phenyl-3-methylpyrazole (phmPz)} have been prepared and characterized by elemental analysis, i.r. and n.m.r. spectroscopy and by single crystal X-ray diffraction methods. The Pd atom in these structures lies on the crystallographic inversion center; in a square-planar coordination geometry made by two sulfur and two nitrogen atoms of the ligands, both in trans positions.

Transporte e características de onda de densidade de carga na ludwigita nomometálica Fe3O2BO3

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese hidrotérmica de nanopartículas de 'TI''O IND.2', de nanocompósitos metal/'TI''O IND.2' e degradação oxidativa de 4-clorofenol em reator membranar fotocatalítico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manganita de lantânio dopada com estrôncio obtida por coprecipitação homogênea: magnetorresistência e magnetorrefletividade

Pós-graduação em Química - IQ

Crescimento e caracterização dos cristais de sulfato de níquel hexahidratado dopados com íons [MnH2O]2+ e com sulfato de magnésio heptahidratado

Neste trabalho, cristais de sulfato níquel dopados com íons de manganês (NSH: Mn) e cristais de sulfato níquel dopados com de íon de magnésio (NMgSH) foram crescidos e posteriormente caracterizados pelas técnicas de difração de raios X e de espectroscopia Raman. Os resultados obtidos mostraram que os cristais dopados possuem estrutura muito semelhante a do cristal de sulfato de níquel puro (NSH), com uma deformação anisotrópica nas dimensões da célula unitária em relação ao cristal puro. O objetivo do presente estudo foi crescer dois novos monocristais de boa qualidade óptica para serem usados como filtros ópticos de banda passante. Os cristais de sulfato de níquel hexa-hidratado (NHS) são conhecidos por possuírem espectros de transmissão óptica, que tem atraído muita atenção, pois apresentam duas regiões com alta eficiência de transmissão, aproximadamente 80%, sendo a primeira região entre 200 e 350 nm e a segunda entre 400 e 600 nm, e uma alta eficiência de absorção em outras regiões do espectro UV-VIS. Um espectro de transmissão de luz com estas características é semelhante a um filtro óptico. Analises Termogravimetric (TGA) foram realizadas para cristais puros e dopados. A temperatura de decomposição obtida para o NSH foi de 73 ° C, enquanto que os cristais de NSH:Mn e NMgSH apresentam valores de 82 ° C e 86 º C, respectivamente. Como pode ser facilmente percebido, a estabilidade térmica de cristais com o íons de Mn ou Mg em suas estruturas é significativamente maior. A banda de transmissão entre 200 e 350 nm no espectro óptico de NSH foi observada com redução significativa em sua largura nos espectros de transmissão dos cristais dopados restringindo assim a região do espectro conhecida como UVA.

Investigação estrutural e efeitos imunológicos e tuberculostáticos de complexos de paládio(II)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese e caracterização de novos complexos de vanádio: estudo da utilização dos complexos no tratamento do Diabetes Mellitus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nanotubos óxidos aplicados a resinas compostas fotoativadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)