Thermal properties of metal-metal bonded Pd(I) complexes supported onto porous Vycor glass

Thermal behavior of the complexes Pd2(dppm)2Cl2, Pd2(dppm)2(SnCl3)Cl and Pd2(dppm)2(SnCl3)2 (dppm = bis[diphenylphosphino(methane)], ((C6H5)2PCH2P(C6H5)2) in the solid state and immobilized onto porous Vycor glass was studied. Similar decomposition mechanisms were observed for the solid and immobilized complexes, with a small thermal stabilization upon immobilization. The decomposition products were characterized by X-ray diffractometry, Raman and diffuse reflectance infrared spectroscopy, which indicated the presence of a mixture of metallic palladium and oxidized species such as PdO,condensed phosphates, SnO2 and SnP2O7. According to X-ray diffractometry, the decomposition products of the immobilized complexes presented higher amounts of PdO than the solid-state residues, probably as an effect of interactions with silanol groups present in the glass surface.Estudos dos complexos Pd2(dppm)2Cl2, Pd2(dppm)(SnCl3)Cl e Pd2(dppm)2(SnCl3) (dppm = bis[diphenylphosphino(methane)], (C6H5)2PCH2P(C6H5)2) por análise termogravimétrica (TG), no estado sólido e imobilizados no vidro poroso Vycor, são descritos. Os mecanismos de decomposição dos complexos no estado sólido e imobilizados no vidro poroso Vycor são similares e apenas uma ligeira estabilização é observada mediante a imobilização. Os produtos de decomposição foram caracterizados por difração de raios-X, espectroscopias Raman e de Refletância difusa no infravermelho, indicando a presença de uma mistura de paládio metálico e espécies oxidadas tais como PdO, fosfatos condensados, SnO2 e SnP2O7. Os produtos de decomposição dos complexos imobilizados no PVG apresentaram quantidades mais elevadas de PdO do que os resíduos no estado sólido, segundo a difração de raios-X, em virtude provavelmente da ocorrência de reações com grupamentos da superfície do vidro, bem como pelo fato de que as moléculas adsorvidas se encontram isoladas umas em relação às outras.263269Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Thermal Properties Of Metal-metal Bonded Pd(i) Complexes Supported Onto Porous Vycor Glass.

Thermal behavior of the complexes Pd2(dppm)2Cl2, Pd2(dppm)2(SnCl3)Cl and Pd2(dppm)2(SnCl3)2 (dppm=bis[diphenylphosphino(methane)], ((C6H5)2PCH2P(C6H5)2) in the solid state and immobilized onto porous Vycor glass was studied. Similar decomposition mechanisms were observed for the solid and immobilized complexes, with a small thermal stabilization upon immobilization. The decomposition products were characterized by X-ray diffractometry, Raman and diffuse reflectance infrared spectroscopy, which indicated the presence of a mixture of metallic palladium and oxidized species such as PdO,condensed phosphates, SnO2 and SnP2O7. According to X-ray diffractometry, the decomposition products of the immobilized complexes presented higher amounts of PdO than the solid-state residues, probably as an effect of interactions with silanol groups present in the glass surface.80263-

Formation of a Novel Polypyrrole/Porous Phosphate Glass Ceramic Nanocomposite

This work is concerned with evidences of a new composite system, formed by in situ polimerization of pyrrole moieties in the copper-exchanged pore surface of LiTi2(PO4)3 glass ceramic

Synthesis of cyclodextrin polymers containing glutamic acid and their use for the synthesis of Ag nanoparticles

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPITEC - FUNDAÇÃO DE APOIO À PESQUISA E À INOVAÇÃO TECNOLÓGICA DO ESTADO DE SERGIPECNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCrosslinking and functionalizing agents play crucial roles in the properties/applications of cyclodextrin polymers. Here we report the synthesis of water-insoluble cyclodextrin polymers containing l-glutamic acid. In a first route, β-cyclodextrin was cros2021119CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPITEC - FUNDAÇÃO DE APOIO À PESQUISA E À INOVAÇÃO TECNOLÓGICA DO ESTADO DE SERGIPECNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPITEC - FUNDAÇÃO DE APOIO À PESQUISA E À INOVAÇÃO TECNOLÓGICA DO ESTADO DE SERGIPECNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçãosem informaçãosem informaçã

Nanocomposites of CdS Nanocrystals with Montmorillonite Functionalized with Thiourea Derivatives and Their Use in Photocatalysis

Nanocomposites of CdS were prepared in refluxing DMF using a montmorillonite organofunctionalized with thiourea derivatives, with different proportions of the matrix relative to Cd²⁺ ions. The matrix provided sulfur atoms for CdS formation as well as specific binding sites for systematic anchoring of the nanocrystals. However, addition of thiourea to the reaction medium was required in order to yield cubic CdS nanocrystals, and increasing the thiourea/Cd²⁺ molar ratio led to the formation of mixtures of cubic and hexagonal CdS. The samples obtained using a thiourea/Cd²⁺ ratio of 2, with cubic CdS, exhibited photoluminescence due to both direct recombination and surface trap states. The distribution of CdS throughout the matrix was characterized by the presence of aggregates (with diameters in the region of 50 nm) of nanocrystals (with diameters less than 7 nm) on the outer surface as well as small pillars in the interlayer region. The photocatalytic performance of the nanocomposites was tested in the degradation of Rhodamine 6G under sunlight irradiation, with promising results in terms of degradation time and degree of mineralization