RESUMO
Photoactive films consisting of pure anatase, brookite or rutile TiO2 were prepared by dip coating from water dispersions obtained by using TiCl4 as the precursor under similar mild experimental conditions.
Assuntos
Luz , Membranas Artificiais , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Titânio/química , Titânio/efeitos da radiação , 2-Propanol/química , 2-Propanol/efeitos da radiação , Tamanho da Partícula , Fotoquímica , Propriedades de Superfície , Fatores de Tempo , Água/químicaRESUMO
Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.
RESUMO
The reaction of Ln(acac)(3).3H(2)O (Ln = Sm, Eu, Gd, Dy, Yb) with K[Cr(2)(CO)(10)(micro-H)] at different molar ratios and solvents leads to the formation of nonanuclear lanthanide hydroxo acetylacetonate complexes of general formula [Ln(9)(OH)(10)(acac)(16)][HCr(2)(CO)(10)]. The compounds are isomorphous, and the common cationic cluster core consists of a novel square antiprismatic arrangement of nine Ln atoms connected by micro(3), micro(4) hydroxo bridges and/or by acetylacetonate ligands as it results from the single-crystal X-ray analysis of the Sm derivative for which the most suitable crystals were obtained.
