Delamination and aromatic amine intercalation of layered aluminophosphate with [Al3P4O16]3− stoichiometry

The delamination and intercalation of a layered microporous aluminophosphate, [Al3P4O16]3−⋅3[CH3(CH2)NH3]+ (AlP), with aromatic amine have been carried out and were followed by XRD and SEM measurements. The basicity of the amine plays an important role in this process, as do the dielectric constant of the solution and the amount of amine added. A saturated benzylamine (pKa of 9.34) intercalate of the aluminophosphate are obtained in solutions with dielectric constant of 50-70 and an amine concentration of 10 mmol/g AlP, while no aniline (pKa of 4.60) intercalates are formed under similar conditions. The remarkable effect of basicity of the amine can be explained by a metathetical balanced reaction model, which was proved by the results of the intercalation processes of 4-methylpiridine (pKa=6.00) and 4-methylimidazole (pKa=7.55).