Meet the Cerium(IV) Phosphate Sisters: Ce^IV(OH)PO₄ and Ce^IV₂O(PO₄)₂

Abstract

Abstract Two new cerium(IV) phosphates were obtained: cerium(IV) hydroxidophosphate, Ce(OH)PO 4 , and cerium(IV) oxidophosphate, Ce 2 O(PO 4 ) 2 , which were shown to complement the classes of isostructural compounds M(OH)PO 4 and R 2 O(PO 4 ) 2 , where M=Th, U and R=Th, U, Np, Zr. Ce 2 O(PO 4 ) 2 oxidophosphate is formed by elimination of H 2 O from the crystal structure of Ce(OH)PO 4 during its thermal decomposition. The structures of Ce(OH)PO 4 and Ce 2 O(PO 4 ) 2 are related to each other with the same Cmce space group and similar unit cell parameters ( a =6.9691(3) Å, b= 9.0655(4) Å, c =12.2214(4) Å, V= 772.13(8) Å 3 , Z =8; a =7.0220(4) Å, b= 8.9894(5) Å, c =12.544(1) Å, V= 791.8(1) Å 3 , Z =4, respectively).