An Unprecedented Uranyl Phosphate Framework in the Structure of [(UO2)3(PO4)O(OH)(H2O)2](H2O)

The new uranyl phosphate [(UO2)3(PO4)O(OH)(H2O)2] (H2O) (1) with an unprecedented framework structure has been synthesized at 150 and 185 °C. The structure (tetragonal, P42/mbc, a = 14.015(1) Å, c = 13.083(2) Å, V = 2575.6(4) Å3, Z = 8) contains uranyl phosphate chains composed of uranyl pentagonal and hexagonal bipyramids and phosphate tetrahedra linked by sharing of polyhedral edges. The uranyl phosphate chains are aligned both along [100] and [010] and are linked into a novel framework structure involving channels along [001]. Topologically identical chains occur linked into sheets in more than a dozen uranyl phosphate minerals, but these chains have never been observed in opposing orientations and linked into a framework as in 1.