STRUCTURE OF BIS(AMMONIUM) HEXANITRATOPLUTONIUM(IV) AND BIS(AMMONIUM) HEXANITRATOTHORIUM(IV)

[NH4]2[Pu(NO3)6], M(r) = 650.11, monoclinic, P2(1)/n, a = 8.162 (3), b = 6.809 (2), c = 13.089 (4) angstrom, beta = 91.34 (3)-degrees, V = 727.2 (4) angstrom3, Z = 2, D(x) = 2.969 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 5.5252 mm-1, F(000) = 604, T = 295(1) K, R = 0.037 for 845 observed reflections [I > 2-sigma(I)]. [NH4]2[Th(NO3)6], M(r) = 640.13, monoclinic, P2(1)/n, a = 8.321 (3), b = 6.890 (3), c = 13.097 (4) angstrom, beta = 91.55 (3)-degrees, V = 750.6 (4) angstrom3, Z = 2, D(x) = 2.832 Mg m-3, lambda(Mo K-alpha) 0.71073 angstrom, mu = 10.3972 mm-1, F(000) = 596, T = 295(1) K, R = 0.0463 for 809 observed reflections [I > 2-sigma(I)]. The two complexes are isostructural. The actinide atom lies on a symmetry centre [at 2(a)]. It is twelve coordinated by O atoms which belong to six bidentate nitrate ions. The coordination polyhedron is an irregular icosahedron with An-O distances ranging from 2.454 (6) to 2.516 (5) angstrom and 2.545 (6) to 2.608 (5) angstrom, respectively, for Pu and Th. The connection between the [An(NO3)6]2 anions and the [NH4]+ cations is realized through a three-dimensional network of hydrogen bonds.