Abstract
The new niobium phosphates Ba2[NbOF(PO4)2] (1) and Ba3[Nb3O3F(PO4)4(HPO4)](H2O)7 (2) have been synthesized in single crystal form by hydrothermal reactions at mild temperatures. Their crystal structures determined from X-ray diffraction data are based on defected derivatives of the NbO(H2O)PO4 layers found in hydrated niobium phosphate. The niobium phosphate layers in 1 or 2 can be derived by removing one half or one quarter of the NbO6 octahedra from the NbO(H2O)PO4 layer, respectively. In compound 1 the layers are separated and are held together by interlayer Ba-O and Ba-F bonds while in 2 the layers are linked by interlayer PO4 tetrahedra to form a framework structure.