Synthesis of fluorinated metalloporphyrinosilica imprinted with templates through sol-gel process

We present the synthesis of a hybrid material containing fluorinated iron p orphyrins through hydrolysis and polycondensation of iron porphyrin bearing a trifluorosilyl Function with tetraethoxysilane in the presence of nitrog en bases acting as template molecules. The presence of metalloporphyrin Sor et band is detected in the ultraviolet-visible absorption spectra of all me talloporphyrinosilica-templates. Thermogravimetric analysis and electron pa ramagnetic resonance of the materials also confirm the presence of metallop orphyrin in a silica network. Electron spectroscopy imaging was that of a n on-crystalline microstructure. The iron and silicon distribution are homoge neous for the elements in all particle sites. The iron porphyrinosilicas-te mplate were active as catalysts for cyclooctene epoxidation using iodozylbe nzene as oxygen donor. In general, the epoxidation yield is larger for iron porphyrinosilicas-template than for manganese porphyrinosilicas-template. The manganese porphyrinosilicas-template had a smaller activity due to thei r manganese oxidation state. The largest catalytic yield were obtained with the iron porphyrinosilica-pyridine (85%). (C) 2000 Elsevier Science B.V. A ll rights reserved.