Synthesis and Application of γ-Zirconium Phosphates Modified with Chiral Amines

Abstract

The intercalation of organic phosphate esters and chiral amines into layered γ-zirconium phosphate, Zr (HPO₄)₂·2H₂O (abbreviated ZrP), was examined by powder X-ray diffraction, elemental analysis and IR spectroscopy. The results indicated basal spacings of ZrP intercalated with organic phosphate esters to enlarge in proportion to alkyl chain length. When chiral amines were further intercalated into ZrP derivatives, the basal spacings became slightly longer. The catalytic activity of the modified ZrP derivatives was investigated by adding thiol to enone. Enantiomeric excess was found to depend on the chiral amine employed and the alkyl chain length of organic phosphate.