Uranyl selenite and uranyl tellurite

Loopstra, B.O.; Brandenburg, N. P.

doi:10.1107/s056774087800549x

Cited by 33 publications

(20 citation statements)

References 4 publications

(6 reference statements)

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“…The observed U-O bond lengths in uranyls are close to the average value 1.815 Å [19] and 1.805 Å [6] and agree also with the values proposed by Burns [25][26][27] for the uranyl natural and synthetic compounds having the uranyl pentagonal dipyramidal coordination polyhedra in their crystal structures. The number of the uranyl stretching vibrations observed in Raman and infrared spectra of schmitterite is not in disagreement with the asymmetry of the (O-U-O) 2+ bonds, FGA and number of molecules in the unit cell of schmitterite.…”

Section: Raman Spectroscopysupporting

confidence: 89%

“…The empirical relations by Bartlett and Cooney are used [36]. Obtained U-O bond lengths are close to those inferred from the X-ray single crystal structure of synthetic schmitterite [6,19] and in agreement with those observed in other natural or synthetic uranyl tellurites. …”

Section: Discussionsupporting

confidence: 72%

“…Its synthetic analogue was known since 1962 [4]. The mineral is orthorhombic with space group Pmba, a 7.860(4), b 10.089(2), c 5.363(2) Å [1, 2] or Pbcm with cell parameters a 5.363(3), b 10.161 (4), and c 7.862(3) Å as confirmed from the crystal structure studies of synthetic schmitterite [5][6][7]. There are four formula units in the unit cell.…”

Section: Introductionmentioning

confidence: 98%

“…Infrared spectra of synthetic cliffordite [16] and synthetic schmitterite [17] have been published. Crystal structures of synthetic cliffordite [5,18] synthetic schmitterite [6,7,19] and moctezumite [11] and of some synthetic uranyl tellurites [20][21][22][23] are known.…”

Section: Introductionmentioning

confidence: 99%

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A Raman spectroscopic study of the uranyl tellurite mineral schmitterite

Frost

Čejka

Weier

et al. 2006

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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Raman spectra of schmitterite measured at 298 and 77 K are presented and discussed in detail and in part in comparison with published IR spectrum of synthetic schmitterite. U-O bond lengths in uranyls, calculated with the empirical relations R U-O = f[ν 1 (UO 2 ) 2+ ] Å and R U-O = f[ν 3 (UO 2 ) 2+ ] Å, are close to those inferred from the Xray single crystal structure of synthetic schmitterite and agree also with the data for other natural and synthetic uranyl tellurites.

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Section: Raman Spectroscopysupporting

confidence: 89%

Section: Discussionsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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A Raman spectroscopic study of the uranyl tellurite mineral schmitterite

Frost

Čejka

Weier

et al. 2006

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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“…The structures of the selenite compounds of dioxouranium(VI) UO2SeO3, UO2Se205 and UO2(HSeO3)2.H20 have been characterized previously (Loopstra & Brandenburg, 1978, Trombe, Gleizes & Galy, 1985Mistryukov & Mikhailov, 1983), as have the structures of some rare uranyl-selenite minerals (Ginderow & Cesbron, 1983a,b).…”

Section: Commentmentioning

confidence: 99%

Ammonium Uranyl Hydrogenselenite Selenite

Koskenlinna¹,

Valkonen²

1996

Acta Crystallogr C

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Ammonium uranyl(2+) hydrogenselenate(1-) selenate-(2-), (NH4)[UO2(HSeO3)(SeO3)], has a layered structure with only hydrogen bonding provided by the NHg ion and (probably) the protonated O atom of the hydrogenselenite ion connecting the layers. The U atom is surrounded by a pentagonal bipyramidal arrangement of O atoms. CommentThe structures of the selenite compounds of dioxouranium(VI) UO2SeO3, UO2Se205 and UO2(HSeO3)2.H20 have been characterized previously (Loopstra & Brandenburg, 1978, Trombe, Gleizes & Galy, 1985Mistryukov & Mikhailov, 1983), as have the structures of some rare uranyl-selenite minerals (Ginderow & Cesbron, 1983a,b).In the presence of ammonium ions, within the pH range 4-7, the compound (NH4)2UO2(SeO3)2.0.5H20 crystallizes (Koskenlinna, Mutikainen, Leskel~i & Leskel~i, 1996). We have found that at a lower pH another type of ammonium uranyl selenite can be crystallized. We now report the structure of that compound.The structure of the title compound is layered, with no covalent bonds between the layers. The layers are parallel to the (101) plane. The coordination polyhedron of O atoms around the U v] atom in the title compound is a pentagonal bipyramid, as in UO2(HSeO3)2.H20 and UO2Se205 (Trombe, Gleizes & Galy, 1985;Mistryukov & Mikhailov, 1983). The two short U--O bonds [1.771 (7) and 1.779 (6)A] to the uranyl O atoms form an angle of 175.9 (3) A and the U---O bonds in the pentagonal plane range between 2.325 (6) and 2.417 (6)A,, which makes the geometry the same as those of the coordination polyhedra in the other two compounds. Each O atom of the pentagonal plane is contributed by a different anion (three selenite ions and two hydrogenselenite ions), each of which acts as a monodentate bridging ligand. All three O atoms of the selenite ion and two of the three O atoms of the hydrogenselenite ion are coordinated to a different U vl ion. The protonated O atom of the hydrogenselenite ion is not coordinated to a metal atom. All O atoms in the pentagonal plane appear within bonding distance from only one metal atom. As Fig. 2 shows, each uranyl ion is connected by the ligands to five others, thus forming a two-dimensional network. The H atom of the hydrogenselenite ion was not detected in the difference Fourier maps, but the Se--O bond length and the lack of a coordinated atom

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