Preparation and characterization of spherical silica–porphyrin catalysts obtained by the sol–gel methodology

The influence of addition of a catalyst and chelating agent on the properties of titanium dioxide synthesized via the sol–gel method

“…A typical sol-gel method is based on hydrolysis and condensation of the precursor (inorganic metal salts or metal organic compounds such as metal alkoxides) [24]. This process can be employed for the synthesis of functionalized inorganic oxides with controlled particle size and shape [35][36][37][38][39][40][41][42]. In the sol-gel method, control of the reactivity of the metal alkoxides used as precursors is very important in order to obtain sols and gels with desirable properties.…”

Green Oxidation Reactions of Drugs Catalyzed by Bio-inspired Complexes as an Efficient Methodology to Obtain New Active Molecules

“…Besides its direct toxicity, the use of heavy metals (chromium) is a potential environmental problem to both water and soil qualities, and consequently to plant, animal, and human life (Barros et al, 2007). As part of our work on oxidative catalytic systems involving ironporphyrins (Papacídero et al, 2006), as well as of our studies on the synthesis and biological activities of lignans Da Silva Filho et al, 2004; our group has developed a synthetic method for production of (-)-hinokinin consisting of the oxidation of (-)-cubebin catalyzed by biomimetic heterogeneous metalloporphyrin catalytic systems. Cubebin was isolated by us directly from Piper cubeba.…”

Homogeneous and Heterogeneous Free-Based Porphyrins Incorporated to Silica Gel as Fluorescent Materials and Visible Light Catalysts Mimic Monooxygenases

“…Iron porphyrin catalysts were anchored on the spherical silica gel beads obtained by the solgel route (Biazzotto et al, 2002;Moreira et al, 2005;Papacídero et al, 2006) for the oxidation of (Z)-cyclooctene and cyclohexane with PhIO or H 2 O 2 . Better results were obtained with the electronegatively substituted porphyrin on the SiO 2 supports rendering 86% epoxide yields (Moreira et al, 2005).…”