title: Mixed-valence uranium germanate and silicate: Cs(x)(U(V)O)(U(IV/V)O)2(Ge2O7)2 (x = 3.18) and Cs4(U(V)O)(U(IV/V)O)2(Si2O7)2.
abstract: A new mixed-valence uranium germanate and the silicate analogue have been synthesized under hydrothermal conditions at 600 °C and 165 MPa. Their crystal structures contain infinite -U(V)-O-U(IV/V)-O-U(IV/V)-O-U(V)- chains that are connected by Ge(2)O(7) or Si(2)O(7) groups to form a 3D framework with six-ring channels where the Cs(+) cations are located. Two of the Cs sites in the germanate are partially occupied. Bond-valence-sum calculation and an U 4f X-ray photoelectron spectroscopy study confirm the valence states of the uranium.
authors: Department of Chemistry, National Central University, Jhongli, Taiwan 320, Republic of China.
authors: Chun-Liang
authors: CL
authors: Chen
authors: Quang Bac
authors: QB
authors: Nguyen
authors: Chih-Shan
authors: CS
authors: Chen
authors: Kwang-Hwa
authors: KH
authors: Lii