title: Synthesis and characterization of AU2Se6 (A = K, Cs).
abstract: Two new ternary uranium selenides, AU(2)Se(6) (A = K, Cs), were prepared using the reactive flux method. Single crystal X-ray diffraction was performed on single crystals. The compounds crystallize in the orthorhombic Immm space group, Z = 2. CsU(2)Se(6) has cell parameters of a = 4.046(2) A, b = 5.559(3) A, and c = 24.237(12) A. KU(2)Se(6) has cell parameters of a = 4.058(3) A, b = 5.556(4) A, and c = 21.710(17) A. The compounds are isostructural to the previously reported KTh(2)Se(6). The two-dimensional layered structure is related to ZrSe(3) with the alkali metals residing in the interlayer space. The oxidation states of uranium and selenium were evaluated using X-ray photoelectron spectroscopy (XPS). Uranium was found to be tetravalent, while selenium was found to be in two oxidation states, one of which is -2. The other oxidation state is similar to that found in a polyselenide network. While this structure is known, our work examines how the structure changes through the transactinide series.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Benny C
authors.initials: BC
authors.lastname: Chan
authors.forename: Zeric
authors.initials: Z
authors.lastname: Hulvey
authors.forename: Kent D
authors.initials: KD
authors.lastname: Abney
authors.forename: Peter K
authors.initials: PK
authors.lastname: Dorhout