A review of the structural architecture of tellurium oxycompounds (original) (raw)
Related papers
Mineralogical Magazine
The crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space group P321, with a = 9.1219(17) Å, c = 11.9320(9) Å and V = 859.8(3) Å3, and was refined to R1 = 0.0296 for 786 reflections with I > 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6 octahedra, Te6+O6 octahedra and Te4+O4 disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3 trigonal pyramids and CaO8 polyhedra. SO4 tetrahedra, Ca(H2O)3O6 polyhedra and H2O groups fill the space between t...
A Generalized Crystallographic Description of All Tellurium Nanostructures
Advanced materials (Deerfield Beach, Fla.), 2018
Despite tellurium being less abundant in the Earth's crust than gold, platinum, or rare-earth elements, the number of industrial applications of tellurium has rapidly increased in recent years. However, to date, many properties of tellurium and its associated compounds remain unknown. For example, formation mechanisms of many tellurium nanostructures synthesized so far have not yet been verified, and it is unclear why tellurium can readily transform to other compounds like silver telluride by simply mixing with solutions containing silver ions. This uncertainty appears to be due to previous misunderstandings about the tellurium structure. Here, a new approach to the tellurium structure via synthesized structures is proposed. It is found that the proposed approach applies not only to these structures but to all other tellurium nanostructures. Moreover, some unique tellurium nanostructures whose formation mechanism are, until now, unconfirmed can be explained.
Canadian Mineralogist, 2017
Telluromandarinoite, a tellurite, is a new mineral species from the Wendy open pit, Tambo mine, El Indio-Tambo mining property, Coquimbo Province, Chile. The ideal endmember telluromandarinoite formula is Fe 3þ 2 Te 4þ 3 O 9 Á6H 2 O and it is the Te 4þ analogue of the selenite mineral mandarinoite, Fe 3þ 2 Se 4þ 3 O 9 Á6H 2 O. These deposits are located in rhyolitic and dacitic pyroclastic volcanic rocks of Tertiary age (8-11 Ma) that are strongly hydrothermally altered. The mineralization in the Tambo area is characterized by high-level epithermal veins and breccias located along roughly east-west structures. Hydrothermal breccias consisting of silicified clasts of dacite tuffs cemented by a silica/barite/alunite matrix are common at the occurrence. In fact, all studied specimens containing tellurite mineralization are associated with alunite. Telluromandarinoite is translucent, pale green, with a white streak and vitreous luster. It forms as individual platy crystals, 0.2 mm or less in size, but more commonly as aggregates of platy crystals. The crystals are too small to allow a Mohs hardness determination; they are brittle with an uneven fracture and no observed cleavage or parting. Telluromandarinoite is biaxial positive with a ¼ 1.750(3), b ¼ 1.807(3), and c ¼ 1.910(5), with a calculated 2V ¼ 76.98. The optical orientation is Y ¼ b, cˆZ ¼ 108 in obtuse b. No dispersion was noted and no pleochroism was observed. An average of 10 electron microprobe analyses gave SeO 2 22.91, TeO 2 44.30, Fe 2 O 3 26.43, and H 2 O (calc.) 17.59, total 111.23 wt.%. The mineral loses H 2 O in vacuum, so the high totals obtained were expected. The empirical formula (based on 15 O atoms) is Fe 3þ 2.03 (Te 4þ 1.71 Se 4þ 1.27) R2.98 O 9 Á6H 2 O with Z ¼ 4, and D calc ¼ 3.372 g/cm 3. Spot analyses gave stoichiometries that range from telluromandarinoite Fe 3þ 2.03 (Te 4þ 2.12 Se 4þ 0.86) R2.98 O 9 Á6H 2 O to mandarinoite Fe 3þ 2.07 (Se 4þ 1.64 Te 4þ 1.31) R2.95 O 9 Á6H 2 O. A crystal-structure analysis shows the mineral to be monoclinic, space group P2 1 /c, with a 16.9356(5), b 7.8955(3), c 10.1675(3)Å, b 98.0064(4)8, and V 1346.32(13)Å 3. The strongest lines in the Xray powder pattern [d inÅ,(I),(hkl)] are: 8.431(44)(200), 7.153(100)ð110Þ, 3.5753(41)ð220Þ, 3.4631(21)ð402Þ, 2.9964(34)ð222Þ, 2.8261(19)(412). The crystal structure of telluromandarinoite is similar to that of emmonsite, Fe 3þ 2 Te 4þ 3 O 9 Á2H 2 O.
American Mineralogist, 2013
Chromschieffelinite, Pb 10 Te 6 O 20 (OH) 14 (CrO 4 )(H 2 O) 5 , is a new tellurate from Otto Mountain near Baker, California, named as the chromate analog of schieffelinite, Pb 10 Te 6 O 20 (OH) 14 (SO 4 )(H 2 O) 5 . The new mineral occurs in a single 1 mm vug in a quartz vein. Associated mineral species include: chalcopyrite, chrysocolla, galena, goethite, hematite, khinite, pyrite, and wulfenite. Chromschieffelinite is orthorhombic, space group C222 1 , a = 9.6646(3), b = 19.4962(8), c = 10.5101(7) Å, V = 1980.33(17) Å 3 , and Z = 2. Crystals are blocky to tabular on {010} with striations parallel to [001]. The forms observed are {010}, {210}, {120}, {150}, {180}, {212}, and {101}, and crystals reach 0.2 mm in maximum dimension. The color and streak are pale yellow and the luster is adamantine. The Mohs hardness is estimated at 2. The new mineral is brittle with irregular fracture and one perfect cleavage on {010}. The calculated density based on the ideal formula is 5.892 g/cm 3 . Chromschieffelinite is biaxial (-) with indices of refraction α = 1.930(5), β = 1.960(5), and γ = 1.975(5), measured in white light. The measured 2V is 68(2)°, the dispersion is strong, r < v, and the optical orientation is X = b, Y = c, Z = a. No pleochroism was observed. Electron microprobe analysis provided: PbO 59.42, TeO 3 29.08, CrO 3 1.86, H 2 O 6.63 (structure), total 96.99 wt%; the empirical formula (based on 6 Te) is Pb 9.65 Te 6 O 19.96 (OH) 14.04 (CrO 4 ) 0.67 (H 2 O) 6.32 . The strongest powder X-ray diffraction lines are [d obs in Å (hkl) I]: 9.814 (020) 100, 3.575 (042,202) 41, 3.347 (222) 44, 3.262 (241,060,113) 53, 3.052 (311) 45, 2.9455 (152,133) 55, 2.0396 (115,353) 33, and 1.6500 (multiple) 33.
Structural role of tellurium in the minerals of the pearceitepolybasite group
Mineralogical Magazine, 2013
The crystal structure of a Te-rich polybasite has been refined by means of X-ray diffraction data collected at room temperature (space group P3m1; R = 0.0505 for 964 observed reflections and 94 parameters; refined formula Ag 14.46 Cu 1.54 Sb 1.58 As 0.42 S 9.67 Te 1.33 ). The structure comprises stacking of [(Ag,Cu) 6 (Sb,As) 2 (S,Te) 7 ] 2À A and [Ag 9 Cu(S,Te) 2 (S,Te) 2 ] 2+ B layer modules in which Sb forms isolated SbS 3 pyramids, as occurs typically in sulfosalts, Cu links two S atoms in a linear coordination and Ag occupies sites with coordination ranging from quasi linear to almost tetrahedral. The silver d 10 ions are found in the B layer module along two-dimensional diffusion paths and their electron densities evidenced by means of a combination of a Gram-Charlier development of the atomic displacement factors and a split model. The Te-for-S substitution occurs at the same structural sites that Se substitutes for S in selenopolybasite and the Te occupancy at one of these sites is 0.49, thus suggesting the possibility that 'telluropolybasite' could be found in nature.
Unusual Uranyl Tellurites Containing [Te2O6]4 Ions and Three-Dimensional Networks
Angewandte Chemie International Edition, 2002
Solid-state chemistry of the actinides is the subject of significant investigation because of its relevance to nuclear waste disposal and power generation, [1] mineralogy, [2] and catalysis. [3] One system that is poorly understood is that of the uranyl tellurites, which are currently known only from three minerals, UO 2 (Te 3 O 7), [4] PbUO 2 (TeO 3) 2 , [5] and UO 2 (TeO 3), [6] and the synthetic phase Pb 2 UO 2 (TeO 3) 3. [7] In spite of their low representation, these compounds differ substantially in their dimensionality, [2] the coordination environments of the U VI center, and in the Te IV oxoanions present. The ubiquitous presence of a stereochemically active lone pair of electrons on the Te IV centers certainly plays a substantial role in the crystalline architecture of this family of compounds. However, the general tendency is for oxoanions containing nonbonding electrons to either not affect the overall dimensionality of U VI compounds, or to reduce it from two-dimensional to one-dimensional, as demonstrated by uranyl iodates [8, 9] and selenites. [10] In uranyl tellurites this trend is not observed. The ability of Te IV to bind four or five O atoms in its inner sphere, as found in the ternary phases, BaTe 3 O 7 , [11] BaTe 4 O 9 , [11] TeSeO 4 , [12] UO 2 (TeO 3), [6] and UO 2 (-Te 3 O 7) [4] does not offer a satisfying explanation for the atypical behavior of uranyl tellurites because Pb 2 UO 2 (TeO 3) 3 contains only TeO 3 2À ions, and yet it still adopts a threedimensional architecture. [7] To address the unusual bonding in the uranyl tellurite system we are systematically preparing a series of compounds by hydrothermal methods that differ primarily in their countercations. For example, the reaction of TlCl with UO 2 (C 2 H 3 O 2) 2 ¥2 H 2 O and Na 2 TeO 3 at 180 8C in aqueous media for three days produces Tl 2 [UO 2 (TeO 3) 2 ] (1), whereas, in the absence of TlCl, Na 8 [(UO 2) 6 (TeO 3) 10 ] (2) is isolated instead. The simplicity of the formula of 1 is quite misleading because its structure is far from predictable. The uranyl tellurite architecture in this compound is constructed from uranyl moieties that are bound by five O atoms to create UO 7 pentagonal bipyramids. These polyhedra edge-share to form dimers. The dimers are joined by bridging TeO 3 2À ions to yield one-dimensional chains. The chains are in turn linked by [Te 2 O 6 ] 4À ions that are bischelating/bridging, producing twodimensional 2 1 [UO 2 (TeO 3) 2 ] 2À sheets that are separated by Tl þ ions. Part of a 2 1 [UO 2 (TeO 3) 2 ] 2À sheet is illustrated in Figure 1. Bond valence sum calculations are consistent with U VI and ZUSCHRIFTEN 3576
Crystal Structure of the New Cobalt Tellurite Chloride Co5Te4O11Cl4
Zeitschrift für anorganische und allgemeine Chemie, 2007
The crystal structure of the new compound Co 5 Te 4 O 11 Cl 4 is described. It crystallizes in the triclinic system, space group P-1 with the unit cell parameters a ϭ 822.26(8) pm, b ϭ 1029.7(1) pm, c ϭ 1031.1(1) pm, Ͱ ϭ 110.80(1)°, β ϭ 97.950(9)°, γ ϭ 98.260 °a nd Z ϭ 2. The structure is layered along the bcϪplane and built by [CoO 5 Cl], [CoO 4 Cl 2 ] and [CoO 4 Cl] polyhedra sandwiched by [TeO 3 E] and [TeO 4 E] polyhedra. The layers can be regarded as infi-nite molecules without any net charge and only weak van der Waals forces connect them to each other. The halides and the lone-pair, E, of Te IV protrude from the layers.
Journal of Solid State Chemistry, 1999
Five new compounds in the A x MTeO 6 family were prepared and structurally characterized: Li 2 GeTeO 6 , Na 2 TiTeO 6 , Na 2 SnTeO 6 , and two forms of Na 2 GeTeO 6 . All compounds are layered structures based on various stacking arrangements of MTeO 2؊ 6 layers. The structures of BaGeTeO 6 and SrGeTeO 6 were also determined. The former compound was found to contain Ba 2؉ in trigonal prismatic coordination, in agreement with previous literature reports, while SrGeTeO 6 contains Sr 2؉ in octahedral coordination and is not isostructural with BaGeTeO as was previously reported. Structural characterizations were carried out using a variety of tools, including Rietveld re5nements of X-ray and neutron powder di4raction data, solid-state MAS+ NMR, and Raman and infrared spectroscopy. With the exception of M ؍ Ti 4؉ , the MTeO 2؊ 6 layers show a high degree of order between M 4؉ and Te 6؉ cations within the layers, but the stacking faults are generally present, which results in a signi5cant decrease in the long-range ordering of the M 4؉ and Te 6؉ cations in the third dimension. The compound K 2؊x Na x TiTeO 6 was prepared by reacting Na 2 TiTeO 6 and KNO 3 under hydrothermal conditions at 2003C in a Te6on-lined Parr bomb. This compound adopts a pyrochlore structure with cell edge 10.18 A s . NMR measurements indicate a disordered Ti/Te distribution. 1999 Academic Press 99
Journal of Organometallic Chemistry, 2007
TeX 4 (X = Cl, Br) react in HCl/HBr with [Ph(CH 3) 2 Te]X (X = Cl, Br) to give [PhTe(CH 3) 2 ] 2 [TeCl 6 ] (1) and [PhTe(CH 3) 2 ] 2 [TeBr 6 ] (2). The reaction of PhTeX 3 (X = Cl, Br, I) in cooled methanol with [(Ph) 3 Te]X (X = Cl, Br, I) leads to [Ph 3 Te][PhTeCl 4 ] (3), [Ph 3 Te][Ph-TeBr 4 ] (4) and [Ph 3 Te][PhTeI 4 ] (5). In the lattices of the telluronium tellurolate salts 1 and 2, octahedral TeCl 6 and TeBr 6 dianions are linked by telluronium cations through TeÁ Á ÁCl and TeÁ Á ÁBr secondary bonds, attaining bidimensional (1) and three-dimensional (2) assemblies. The complexes 3, 4 and 5 show two kinds of TeÁ Á Áhalogen secondary interactions: the anion-anion interactions, which form centrosymmetric dimers, and two identical sets of three telluronium-tellurolate interactions, which accomplish the centrosymmetric fundamental moiety of the supramolecular arrays of the three compounds, with the tellurium atoms attaining distorted octahedral geometries. Also phenyl C-HÁ Á Áhalogen secondary interactions are structure forming forces in the crystalline structures of compounds 3, 4 and 5.