Immobilization of iron(III) porphyrins on exfoliated MgAl layered double hydroxide, grafted with (3-aminopropyl)triethoxysilane

MgAl layered double hydroxide (LDH) intercalated with dodecylsulfate, was exfoliated in toluene, and the single-layer suspension was reacted with (3-aminopropyl)triethoxysilane (3APTS) in the same solvent. After washing with toluene and acetone to remove the excess reagent and drying procedure, the solid was reacted with neutral and anionic iron(III) porphyrins in toluene and methanol, respectively. The products were analyzed by powder X-ray diffraction, Fourier transform infrared spectroscopy, electron paramagnetic resonance, ultraviolet-visible light, and atomic absorption spectrometric techniques. All of the data are consistent with the grafting of the LDH interlayers with 3APTS and immobilization of the iron porphyrins on the pendent terminal amino groups positioned at the top the grafted molecule. Based on these results, a schematic representation for the immobilization and preliminary catalytic oxidation reactions is presented.