Fluorine-containing organic molecules as structure directing agents in the synthesis of crystalline microporous materials. Part I: Synthesis of AlPO4-5 and SAPO-5 from fluorobenzyl-pyrrolidine

The effect of the presence of fluorine atoms in structure directing agents used for the synthesis of the AFI-type structure has been investigated. Syntheses of AlPO4-5 (AlPO) and SAPO-5 (SAPO) materials have been carried out by using benzyl-pyrrolidine and its mono-fluorinated derivatives in ortho, meta and para positions of the benzenic ring as templates. In both AlPO and SAPO compositions, the presence of the fluorine atom in meta position improves the templating ability of benzyl-pyrrolidine. However, fluorine in ortho and para positions deteriorates the structure directing role of the aromatic amine. The materials synthesized with benzyl-pyrrolidine and the meta-fluoro isomer have been characterized. The presence of fluorine does not seem to influence the silicon distribution in the framework.