A novel open-framework cerium phosphate fluoride: (NH4)[(CeF2)-F-IV(PO4)]

A novel open-framework cerium phosphate fluoride, (NH4)[(CeF2)-F-IV(PO4)], has been synthesized under hydrothermal conditions and characterized by mea ns of single-crystal X-ray diffraction, ion chromatography analysis, and th ermal analysis. The compound crystallizes in the monoclinic space group P2( 1)/m (No. 11), with a = 6.660(2), b = 5.875(2), c = 7.177(3) Angstrom, beta = 114.31(2)degrees, and V = 255.9(2) Angstrom (3) (R = 0.039 and R-w = 0.0 45). Tn this compound, the cerium-centered CeO4F4 polyhedra link via Ce2F2 rings to form corrugated chains along the b axis of the structure. These ar e tetrahedrally connected via PO4 groups to create the three-dimensional ne twork with a one-dimensional channel. NH4+ cations are accommodated at the intersection of the channels. (C) 2001 Academic Press.