Intercalation of 2-aminoethylamino-substituted β-cyclodextrin by γ-zirconium phosphate

Abstract

The uptake of [6-(2-aminoethylamino)-6-deoxy]-β-cyclodextrin (cden) by γ-zirconium phosphate Zr(HPO₄)₂·2H₂O has been studied at 25 °C. The intercalation behaviour of cden for the γ phosphate is in marked contrast to that observed previously with α-zirconium phosphate Zr(HPO₄)₂·H₂O. The γ phosphate forms initially an intercalated phase in which the cden molecules are arranged as a bilayer of thickness 31.3 Å with cavity axes parallel to the phosphate layers. With further increase in the amount of cden added, the thickness of the intercalant layer rapidly decreases to 24.7 Å, with an accompanying appreciable decrease in the cden content.