Amino ironporphyrinosilica hybrid materials

This work describes the optimized conditions for preparation of the new catalyst iron(III) porphyrinosilica-template material (FePS-template), using iron(III)-2,6-dichore-3-aminephenylporphyrin (FeTDC(NH2)PP+) and 3-chloropropyltrimethoxysilane as the organosilane precursor. The monomer precursor iron(III) porphyrinopropylsilyl species was prepared and monomer polycondensation with tetraethoxysilane (TEOS), through a sol-gel process, make a hybrid material FePS. For comparison with FePS, a similar free base porphyrinosilica (H2PS) was prepared. FeP was also entrapped in the porous matrix without covalent bond between the organic and inorganic fragments (FePD). The FePS-template materials had the characteristic ultra-violet-visible absorption spectra pattern of the corresponding metalloporphyrin (MeP) in solution. Electron paramagnetic resonance show the presence of a small amount of Fe-III with typical g value at similar to6 and the presence of various species of iron porphyrins in a rhombic symmetry. FePS-template materials present pore size between 1.5 and 100 nm and surface area between 700 and 950 m(2) g(-1). The use of template molecules with different size and shape allowed the preparation of catalysts with different pore size. (C) 2001 Elsevier Science B.V. All rights reserved.