Single crystal growth and structural characterization of ternary transition-metal uranium oxides: MnUO4, FeUO4, and NiU2O6

Single crystals of MnUO4, FeUO4, and NiU2O6 were grown for the first time. The use of chloride fluxes facilitated the crystal growth. MnUO4, a hexavalent uranium compound, crystallizes in the orthorhombic space group, Imma, with a = 6.6421(19) Angstroms, b = 6.978(2) Angstroms, and c = 6.748(2) Angstroms, and exhibits typical uranyl, UO22+, coordination. FeUO4 and NiU2O6 contain pentavalent uranium and are structurally related, exhibiting three-dimensional connectivity. FeUO4 crystallizes in the orthorhombic space group, Pbcn, with a = 4.8844(2) Angstroms, b = 11.9328(5) Angstroms, c = 5.1070(2) Angstroms. NiU2O6 crystallizes in the trigonal space group, P321, with a = 9.0148(3) Angstroms, c = 5.0144(3) Angstroms. (authors)