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Title: Synthesis, structure, and characterization of uranium(IV) phenyl phosphonate, U(O{sub 3}PC{sub 6}H{sub 5}){sub 2}, and uranium(IV) pyro phosphate, UP{sub 2}O{sub 7}

Journal Article · · Journal of Solid State Chemistry
; ;  [1]
  1. Universidade de Malaga (Spain); and others

Two tetravalent uranium compounds have been characterized. The structure of a new uranium(IV) phosphonate, U(O{sub 3}PC{sub 6}H{sub 5}){sub 2}, has been solved from laboratory X-ray powder diffraction data by using ab initio methodology, U(O{sub 3}PC{sub 6}H{sub 5}){sub 2} crystallizes in the space group Cw/m with a = 9.4559(7) {Angstrom}, b = 5.6769(5) {Angstrom}, c = 14.9687(12) {Angstrom}, {Beta} = 96.539(5) {Angstrom}, V = 798.3(1) {Angstrom}{sup 3}, Z=2. The reliability factors were R{sub WP} = 8.0%, R{sub p} = 6.04%, and R{sub F} = 3.0%. The structure is lamellar, and the framework of the U(O{sub 3}P){sub 2} layers is similar to that of the {alpha}-Zr(HOP{sub 4}){sub 2} {center_dot} H{sub 2}O and the phosphonate group in Zr(O{sub 3}PC{sub 6}H{sub 5}){sub 2}. The phenyl groups are located in the interlamellar space, being inclined 10{degrees} to the c-axis. The phenyl rings are tilted out 53{degrees} from the ac plane, and they are disordered. The authors have also characterized this compound by UV-VIS-IR spectroscopies and thermal analysis. The thermal decomposition product is uranium(IV) pyro phosphate. This compound was identified through its X-ray powder diffraction pattern. UP{sub 2}O{sub 7} crystallizes in the Pa3 space group (a = 8.6311(2) {Angstrom}, V = 642.99(4) {Angstrom}{sup 3},Z=4). The structure belongs to the cubic ZrP{sub 2}O{sub 7-}type structure. The reliability factors were R{sub WP} = 11.7%, R{sub p} = 8.6%, and R{sub F} = 10.4%. Disorder has been found in the oxygen that bridges the pyrophosphate groups, leading to an angular P-O-P arrangement. The VIS-near-IR adsorption spectra revealed the uranium(IV) presence and the oxygen environment.

OSTI ID:
223716
Journal Information:
Journal of Solid State Chemistry, Vol. 121, Issue 1; Other Information: PBD: 5 Jan 1996
Country of Publication:
United States
Language:
English