Crystal structure and spectroscopic studies of NaGd(PO3)4

Single crystals of gadolinium–sodium polyphosphate NaGd(PO3)4 were grown for the first time using a flux method and characterized by X-ray diffraction. This phosphate crystallizes in a monoclinic system with P21/n space group and with the following unit-cell dimensions: a = 9.767(3) Å, b = 13.017(1) Å, c = 7.160(2) Å, β = 90.564(5)°, V = 910.3(4) Å3 and Z = 4. The crystal structure was solved from 3451 X-ray independent reflections with final R(F2) = 0.0219 and Rw(F2) = 0.056 refined with 164 parameters (F02>4σ(F02)). The atomic arrangement can be described as a long chain polyphosphate organization. Two infinite (PO3)∝ chains with a period of eight tetrahedra run along the [0 1 1] direction. The structure of NaGd(PO3)4 consists of GdO8 polyhedra sharing oxygen atoms with phosphoric group PO4. Each Na+ ion is bonded to eight oxygen atoms.