Low-temperature syntheses of a 1,4-diazabicyclo[2.2.2]-octane-intercalated phosphatoantimonic acid
Abstract
Hydrothermal syntheses in the presence of 1,4-diazabicyclo[2.2.2]octane (dabco) have been undertaken in the antimony phosphate system, giving dabco-intercalated phosphatoantimonic acid with [(Sb3O6(PO4)2}n]3n– layers similar to those in K3[Sb3O6(PO4)2·5H2O. The same material can be prepared by titration of the layered phosphatoantimonic acid H3Sb3O6(PO4)2·xH2O 1 with a dabco solution. It corresponds to the intercalation of 1 mol of dabco per mol of 1, i.e. a neutralization of 2/3 of the acidity. The compound H3Sb3O6(PO4)2(dabco)·4H2O has been analysed and characterized by thermal analysis. X-Ray diffraction, IR and MAS NMR spectroscopies (1H, 31P). A structural model is proposed.