title: Phosphorous acid and urea: valuable sources of phosphorus and nitrogen in the hydrothermal synthesis of ammonium-thorium phosphates.
abstract: Microcrystals of the first ammonium-thorium phosphates, (NH 4) 2Th(PO 4) 2.H 2O (tetragonal, I4 1/ amd, a = 7.0192(4) A, c = 17.9403(8) A) and NH 4Th 2(PO 4) 3 (monoclinic, C2/ c, a = 17.880(6) A, b = 6.906(1) A, c = 8.152(2) A, beta = 104.39(2) degrees ) were hydrothermally obtained from a Th(NO 3) 4-CO(NH 2) 2-H 3PO 3-H 2O system ( T = 180 degrees C). In both cases, the structure consists of a three-dimensional framework with PO 4 tetrahedra coordinated to Th atoms (ThO n polyhedra, where n = 8 or 9, for the tetragonal or monoclinic phase, respectively). The ammonium ions (and water molecules) are located in the tunnels.
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, 33006 Oviedo, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Salvadó
authors.forename: Pilar
authors.initials: P
authors.lastname: Pertierra
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Bortun
authors.forename: Camino
authors.initials: C
authors.lastname: Trobajo
authors.forename: José R
authors.initials: JR
authors.lastname: García