Tellurium

0.096 %

{ syn. }

{ syn. }

2.603 %

0.908 %

4.816 %

7.139 %

18.952 %

{ syn. }

{ syn. }

31.687 %

{ syn. }

{ syn. }

33.799 %

Risk

Tellurium [ tɛlu ː r] (Latin tellus "earth" ) is a rare chemical element with the atomic symbol Te and atomic number 52 in the periodic table it is in the sixth main group (Group 16) and 5th period, making it one of the chalcogens. Its frequency is approximately equal to that of gold, with which it enters into various compounds that occur in nature as minerals. Crystalline Tellurium is a silvery-white, shiny metallic semimetal, which resembles tin and antimony in appearance. It reacts brittle mechanical load and can therefore be easily pulverized. In chemical compounds with nonmetals, it is close in its behavior sulfur and selenium, in alloys and intermetallic compounds, however, it shows very pronounced (semi-) metallic properties.

• 5.1 Physical Properties
• 5.2 Chemical Properties

History

Tellurium in 1782 by the Austrian chemist and mineralogist Franz Joseph Müller von Hory ( 1740-1825 ) in studies of gold ore from the mine at Mount Mariahilf Faczebaja at Zlatna (Eng. small Schlatten, Hungarian Zalatna ) near Sibiu (German Sibiu, Transylvania, Romania) discovered that yielded a lower gold recovery than expected. He became aware of the ores by the scientific treatise message from dignified Spies glass king in Transylvania by Ignaz von Born ( 1742-1791 ). ( Spies Glass King called dignified antimony, Spies glass is an old name for the mineral stibnite ( stibnite, gray antimony, Sb2S3 ) ). Born From the tasteful metal held in the gold ores of antimony and led the low yield back to a compound of gold with antimony. Müller of rich stone disagreed with this view and held it first for " sulfurized bismuth ". After further investigation, the results of which he published in a four-part treatise 1783-1785, but he also ruled out bismuth as the metal, in contrast to antimony and bismuth, practically did not react with sulfuric acid. He gave the name of the metallic phase Metallum problematicum (also aurum aurum paradoxum problematicum respectively ). According to current knowledge, there is a tasteful addition to tellurium in the minerals nagyagite ( Blättererz, AuPb (Pb, Sb, Bi) Te2 - 3S6 ) and sylvanite ( Schrifttellur, (Au, Ag) Te2 ). Müller of rich stone suspected that Metallum problematicum " ... maybe not yet seye a new previously unknown semimetal? " However, wanted his findings only from the Swedish mineralogist and chemist Torben Olof Bergman (1735-1784) confirm. In 1783 he sent the ore samples for review to Bergman, but he received no definitive answers. Bergman died in 1784 and the studies on Metallum problematicum 1785 were adjusted for the time being.

It was not until twelve years later, in 1797, was Martin Heinrich Klaproth ( 1743-1817 ) in Berlin samples of ores from Müller of rich stone. Klaproth confirmed the conclusions from Müller of rich stone studies, and saw enough evidence for the discovery of a new element. In January 1798 Klaproth recognized the merits of Müller rich stone in a lecture and wrote to him the discovery of the new element to. ( " Earth" Latin tellus ) Since Müller of rich stone had given the item a name, Klaproth himself chose the name tellurium:

» In order to fill this existing gap in the chemical mineralogy I put here is my salaried with these precious ores tests and experience, whose main result is the discovery and confirmation of a new peculiar metal, which I beylege the borrowed from the old Mother Earth acquisitions Tellurium. "

The original hand pieces of the sample material from the type locality Zlatna that Klaproth had available, are now in the Museum of Natural History in Berlin.

Regardless of Müller of rich stone and Klaproth discovered in 1789, the Hungarian chemist and botanist Paul Kitaibel ( 1757-1817 ), the tellurium in studies of gold ore from the mining site Nagybörzsöny ( German Pilsen ) in Hungary. However, Klaproth mentioned in his published lecture only Müller of rich stone, though he carried a manuscript Kitaibels also had knowledge of his investigations since 1796. In a letter to Kitaibel Klaproth stated, the content of the manuscript had fallen from him, and he had seen in the studies of the ores Müller of rich stone no connection with his work. Klaproth convinced Kitaibel finally, that the discovery of tellurium alone Müller of rich stone should be attributed, as this is already a few years earlier the same observations made ​​in the new element.

The element symbol " Te " was proposed in 1814 by Jöns Jakob Berzelius ( 1779-1848 ) and is used to this day. The first structure determination of crystalline tellurium using X-ray diffraction was carried out in 1924.

Occurrence

Tellurium is a rare element occurring; its share of the earth's crust is about 0.01 ppm ( g / t). With gold, subordinate with silver, copper, lead and bismuth and the platinum metals occurs rarely dignified, so in elemental form in nature before.

Solidity as tellurium belongs to the group of mineral elements, specifically the half-and non-metals and is used in the classification of minerals according to Strunz under the number I/B.03-40 ( 8th edition ) or 1.CC.10 (9th edition), and led by Dana under number 1.3.4.2.

Traces up to larger amounts of selenium can be in native tellurium ( selenium tellurium ). Although it is a rare element in tellurium, is a relatively large number of minerals known as tellurium forms its own minerals, because it is rarely incorporated into sulfides or selenides or sulfates or selenates; for this crystal lattice of the lighter homologues, it is too large. Conversely, however, represent the two lighter homologues frequently tellurium on its lattice sites in crystal structures of tellurium minerals.

Tellurium shows of all elements, the highest affinity to gold and can thus be found abundantly in nature in the form of gold tellurides, minerals with telluride ( Te2 ) and ditelluride anions ( TE22 ). Besides gold and other precious metals, especially lead and bismuth form more natural Telluride, often concomitantly ( paragenesis ) to the dignified metals and gold ores. Less common are minerals with Te4 cations in the crystal structure, also the most important oxide of tellurium, tellurium dioxide TeO2 which occurs as orthorhombic and tetragonal tellurite paratellurite in nature in two modifications. With the other minerals with tellurium (IV ) cations are Oxotellurate ( IV) ( Tellurite ), the complex [ TeO3 ] 2 - or [ TeO4 ] 4 - containing anions. Minerals with Te6 cations in the form of octahedral [ TeO6 ] 6 - complex anions are extremely rare, there are 21 minerals known, most of which contain copper and lead. In addition to these minerals exist in nature also mixed valence Tellurminerale, including the calcium - Oxotellurat (IV, VI ) Carlfriesit CaTe3O8 with a Te4 : Te6 ratio of 2:1. The minerals with Te4 and Te6 cations are secondary minerals that have arisen from the weathering of native tellurium and tellurides.

Tellurium-containing minerals are responsible for the technical production of tellurium irrelevant since they occur too infrequently and there are practically no mineable deposits. Among the known localities of native tellurium or tellurium minerals include not only the type locality Zlatna ( Transylvania, Romania), also Moctezuma (Mexico), Cripple Creek (Colorado), Kalgoorlie (Australia) and Calaveras ( California). So far (as of 2012) are 154 tellurium minerals known, of which, however, five ( Dilithium, Imgreit, Kurilit, Sztrokayit, Protojoseit ) have not yet been by the International Mineralogical Association (IMA ) recognized as a distinct minerals or discredited as such. A variety of known minerals with tellurium in different oxidation states is shown in the table below.

Production and representation

Tellurium is recovered together with selenium exclusively from industrial by-products of industrial electrolytic copper and nickel production. In the resulting anode sludge water-insoluble precious metal tellurides and selenides of the formula are M2Ch (M = Cu, Ag, Au, Ch = Se, Te ), which at temperatures above 500 ° C under atmospheric oxygen (O2) and soda (sodium carbonate Na2CO3 ) are reacted. The noble metal cations (M ) to be reduced while elemental metals (M), the telluride anions Oxotelluraten ( IV) ( TeO32 ) oxidized:

Alternatively, this reaction can also saltpetre (sodium nitrate NaNO3 ) under exclusion of air and formation of nitrogen oxides (NO and NO2) take place:

The resulting Natriumtellurat (IV ) Na2TeO3 is then dissolved in water where it reacts as a base and Hydrogentellurat (IV ) ions HTeO3 - forms. The separation of the tellurates (IV) of the selenates also incurred ( IV) in the basic solution is carried out by neutralization with the addition of sulfuric acid ( H2SO4), which precipitates in the water almost insoluble tellurium dioxide TeO2:

The tellurium dioxide can be reduced to elemental tellurium in alkaline solutions either by electrolysis or by chemical means, by dissolution in concentrated mineral acids and introduction of sulfur dioxide SO2, the sulfur from the SO2 molecules (or formed from them in the solution sulfite ion SO32 - ) is oxidized and sulfate ions ( SO42 - ) arise:

For the production of high purity tellurium ( > 99.9 %), the zone melting process is applied.

The annual world production of tellurium was in the years 2007-2011 with an average of 121.6 tons per year (t / a). The main producers are the U.S. (50 t / a ), Japan ( ∅ 44.8 t / a), Peru ( ∅ 14 t / a ) and Canada ( ∅ 12.8 t / a). An overview of the production volumes of each country is shown in the table. Other industrial nations such as Germany probably also produce tellurium, there are, however, no figures.

Modifications

Crystalline tellurium

At standard conditions of tellurium, only one crystalline modification (Te -I or α - Te) is known which is referred to as crystalline or metallic tellurium. It is isotypic to α - selenium, that is, it has the same crystal structure. Tellurium crystallizes in the trigonal crystal system in space group P3121 with lattice parameters a = 446 pm and c = 592 pm and three formula units in the unit cell ( the smallest unit of the crystal structure).

The space group P3121 described by the Hermann- Mauguin symbolism explains the centering of the unit cell as well as the existing symmetry elements. P means that the Bravais lattice is primitive. The reference to the centering of the existing symmetry elements of the space group follow: 31 describes a three-fold screw axis ( reproduction of a particle by rotation through 120 ° and offset ( translation) by 1/ 3 in the direction of the rotation axis ) parallel to the crystallographic c- axis ( ), 2 describes a two-fold rotation axis ( multiplication by 180 ° rotation ) parallel to the three crystallographic a-axis (<100 > ), 1 the symmetry element of the monodentate axis of symmetry or identity ( multiplication by 360 ° rotation, the particles thus formed on yourself ab) in the direction perpendicular to the a-axis and c-axis (<120 > ).

The crystal structure contains one crystallographically distinguishable tellurium with the position coordinates of x = 0.2636, y = 0 and z = 1/3. All other atoms in the crystal structure can be returned by the symmetry elements of the space group existing on this one atom. Since the tellurium coincides in its position with the two-fold axis of symmetry of space group ( P3121 ), it is amplified only by the three-fold screw axis ( 31). Characterized spiral chains of covalently bonded tellurium emerge parallel to the c -axis. The tellurium atoms are from each other within the chain 284 pm, the bond angle is 103.1 °. The bonds in the chain are highlighted in red in the pictures, each a chain is shown in blue for clarity, with the dark blue atom at z = 1/3, the medium blue to z = 2/ 3 and the light blue on z = 1 and z = 0 is. Every third atom within the chain is therefore congruent. Each chain is surrounded by six other chains. Between the chains there are van der Waals bonds with Te -Te distances of 349 pm (green dashed line) by the underflow of the van der Waals radius ( 2 × 206 pm = 412 pm ) of the tellurium atoms come about. For a single tellurium this results in a coordination number of 6, more specifically 2 4 as 2 atoms of the same chain are and therefore have a smaller distance than the other 4 on the neighboring strings. As coordination polyhedra, this results in a distorted octahedron ( highlighted in yellow ).

Tellurium can also crystallize in the space group P3221 instead of P3121. The screw axis 32 multiplies an atom also by rotation through 120 °, then it is, however, shifted by 2/3 instead of 1/ 3 in the direction of the axis of rotation. This also gives rise helical chains, however, the wind in the clockwise direction instead of the counterclockwise direction ( in the screw axis 31 ) along the c-axis. The crystal structure in the space group P3221 ("links form " ) is thus the mirror image of the structure in the space group P3121 ( " legal form "). The occurrence of mirror-image crystal forms is known in crystallography as enantiomorphism.

The crystal system of tellurium is often given as hexagonal. The hexagonal and trigonal crystal system is based on the same unit cell, but a hexagonal symmetry, the presence of a six-fold symmetry axis (6, duplication of a particle by rotating through 60 °) would require. However, the crystal structure of tellurium contains only the threefold screw axis ( 31) and thus belongs without doubt in the lower symmetric trigonal crystal system.

In high-pressure experiments with crystalline tellurium (Te -I or α - tellurium), further modifications were discovered. The specified print areas for the stability of the modifications may vary in some cases in the literature:

• Te-II crystallizes in the monoclinic crystal system in the pressure range from 4 to 6.6 GPa. The possible space groups are described in the literature and mentioned.
• Te - III crystallizes in the orthorhombic crystal system and is in the pressure range above 6.6 GPa stable. For an orthorhombic modification, a theoretical calculation exists in the space group.
• Te -IV crystallizes in the trigonal crystal system in the space group and corresponds to the structure of the β - polonium. It is stable in the pressure range from 10.6 to 27 GPa. The distances between the tellurium atoms within the chains and adjacent chains are equal in this modification and are each 300 pm, thus the higher symmetry compared with α -Te is established.
• Te -V is stable above 27 GPa. For this modification, a body-centered cubic lattice (space group ) is assumed.

Amorphous tellurium

The unstable amorphous modification is a brown powder and can be made tellurous acid ( H2TeO3 ) by reaction with sulfurous acid ( H2SO3 ) and sulfite ion ( SO32 - ) are shown. The sulfite ions thereby sulfate ions ( SO42 - ) is oxidized during the Te4 cations are reduced to elemental tellurium:

Amorphous tellurium is changing slowly under standard conditions in the crystalline modification order.

Properties

Physical Properties

Crystalline tellurium is an intrinsic semiconductor with a direct band gap of 0.334 eV. The electrical conductivity can be increased by increasing the temperature or exposure, as in all semiconductors, but this results in only a slight increase tellurium. The electrical conductivity and thermal conductivity behaves in tellurium direction dependent, ie anisotropic. Crystalline tellurium is a soft ( Mohs hardness 2.25 ) and brittle material that can be easily processed into powder. By increasing the pressure to tellurium converts to further crystalline modifications. Above 450 ° C is tellurium into a red melt at temperatures above 990 ° C as a yellow tellurium diamagnetic gas from Te2 molecules before. At temperatures above 2000 ° C, the Te2 molecules disintegrate into individual atoms.

Chemical Properties

Crystalline tellurium is insoluble in water and sparingly soluble in the mineral acids hydrochloric acid and sulfuric acid and in alkaline solutions. However, it is readily soluble in nitric acid, as this is a very strong oxidizing agent and oxidizes elemental tellurium to tellurates with the stable oxidation state IV. Tellurschmelzen attack copper, iron and stainless steel.

In compounds with non- metals, tellurium behaves like the lighter group member selenium. In air, it burns in a green tree, blue flame to tellurium dioxide TeO2:

Tellurium reacts spontaneously with halogens to form Tellurhalogeniden. It is remarkable that tellurium in contrast to the lighter homologues selenium and sulfur also forms thermodynamically stable iodides, including Telluriodid TeI with the oxidation state I. With base metals such as zinc, it reacts violently to the corresponding tellurides.

Isotopes

From tellurium isotopes with mass numbers 105-142 are known. Natural Tellurium is a mixing element consisting of eight isotopes, five of which ( 122Te, 123Te, 124Te, 125Te, 126Te ) are stable. The isotope 123Te should theoretically decompose under electron to 123Sb. This decay is, however, not been observed; the lower limit for the half-life is 9.2 · 1016 years (92 quadrillion years). The isotope 120TE goes over the double electron capture directly in 120Sn. The isotopes 128Te and 130TE transform themselves by emission of beta radiation ( Double beta decay ) in 128Xe or 130XE.

The largest share of natural tellurium forms to about a third of the isotope 130TE with a half-life of 7.9 · 1020 years, followed by isotope 128Te. Therefore, the average atomic mass of natural tellurium isotopes is 127.60 and is therefore greater than that of the following element in the periodic table pure iodine with 126.90. 128Te is considered the isotope with the slowest decay of all unstable isotopes of all elements. The extremely slow decay with a half-life of 7.2 x 1024 years (7 quadrillion years, that is, in one kilograms breaks every 18 months an atom ) could only be due to the detection of the decay product ( 128Xe ) found in very old samples of natural tellurium be.

From other isotopes that Kernisomer 121mTe 154 days, the longest half-life. Are also among the isotopes 127Te and 129Te half-lives of the isomers than those of the ground state. 127Te isotope as a tracer is most frequently used, followed by 121Te. The isotopes 127Te and 129Te also occur as fission products in nuclear fission in nuclear reactors.

→ See also: List of tellurium isotopes

Use

Tellurium is a technically less important element, since it is expensive to manufacture and can be replaced frequently in use by other elements or compounds. Elemental tellurium is in the metal industry, among others, as an additive (< 1%) for steel, cast iron, copper and lead alloys and used in stainless steels. It promotes the corrosion resistance and improves the mechanical properties and the machinability. As semiconductor pure tellurium is little used, usually tellurium is used in the II-VI compound semiconductors. Cadmium telluride is, for example, used in photodiodes and thin-film solar cells to generate electricity from light. Bismuth telluride Bi2Te3 is used in thermocouples to generate electricity in thermoelectric generators (eg radionuclide ) or in Peltier elements for cooling.

Combinations of germanium antimony telluride, GeTe and Sb2Te3 be used in phase -change materials as a component of optical discs (eg, CD -RW) or in novel storage materials such as Phase Change Random Access Memory.

Glasses of tellurium dioxide TeO2 be used due to the high refractive indices instead of silica glass SiO2 in optical waveguides.

In microbiology with colorless Kaliumtellurat (IV ) K2TeO3 offset agar is used as a selective culture medium for the detection of Staphylococcus and Corynebacterium diphtheriae. The bacterial colonies appear here as small black balls, because they reduce the Te4 cations to elemental tellurium and store it in their cells

Furthermore, small amounts of tellurium for vulcanization of rubber, in detonators and for coloring glass and ceramics are used. The salts of tellurium are partially used to generate a grass-green color in fireworks.

Safety and toxicity

Tellurium is a toxic element for the human body and is usually marked with the appropriate symbol "T". However, since elemental tellurium is very poorly soluble in water and endogenous acids, it has now been downgraded from the Institute of Occupational Safety and Health of the German Social Accident Insurance on harmful (Xn ). Recent studies of the Netherlands Organization for Applied Scientific Research ( TNO) showed that the LD50 (oral ) value for rats is> 5000 mg / kg and the specified in most MSDSs value of 83 mg / kg probably valid only for readily soluble tellurium compounds. Most manufacturers use but still the old symbol " T" in conjunction with the R-phrase 25 ( " Toxic if swallowed ").

Tellurium is not as toxic as the selenium. This is in analogy to the adjacent elements of the main group 5, where the antimony is also less toxic than the arsenic. Where tellurium mainly in the form of easily soluble tellurium compounds such as alkali metal tellurates (for example Na2TeO3 ) by ingestion ( orally ) in the body, formed by reduction of toxic Dimethyltellurid ( Me2Te: H3C -Te -CH 3 ), which leads to damage to the blood, liver, can cause heart and kidney. As readily soluble tellurium compounds, releasing far more tellurium, they are also classified as hazardous. Tellurvergiftungen manifest themselves as an intense garlic odor of the breath, which is caused by the Dimethyltellurid. It is also excreted via the skin slowly.

Tellurium dust may ignite in air itself and finely dispersed in a suitable concentration also react explosively, with each tellurium dioxide TeO2 forms. Like other metal dusts may react explosively tellurium with inter-halogen compounds such as bromine pentafluoride BrF5. Tellurium powder is additionally indicated by the R -phrases and S -phrases 36/37/38 26 and 37. The maximum workplace concentration (MAK) is given as 0.1 mg/m3.

Proof

Elemental tellurium can in hot concentrated sulfuric acid ( H2SO4) by oxidation of tellurium to form the red TE42 cation ( Tetratellur dication ) are detected. A portion of the sulfuric acid is reduced at the reaction to sulfurous acid ( H2SO3 ), which due to the high temperatures in water ( H2O) and its anhydride, sulfur dioxide ( SO2) decays, which escapes as a gas:

The color of the square- planar construction TE42 cation comes about through six delocalized π - electrons, which absorb some of the visible light. The remaining non- absorbed wavelengths of light give the complementary color of red

Tellurate and tellurite can speziiert by polarography, ie be selectively determined simultaneously. While the level of Tellurats is -1.66 V, that of the Tellurits appears at -1.22 V ( vs. SCE, 0.1 M sodium hydroxide ). Both Tellurspezies are thereby reduced in one step to Telluride. Traces of 0.03% or 0.003% tellurite tellurate can be detected in this way. Much stronger proof are the methods of atomic spectroscopy. While you can reach by flame AAS detection limit of 20 ug / l, this value ( 0.02 g / l) still significantly lower in the graphite furnace AAS ( 0.2 g / l ) and the hydride.

Tellurium compounds

In tellurium compounds most commonly occurs in the oxidation states II (Telluride ) and IV ( tetrahalides, tellurium dioxide and tellurates (IV ), Tellurite outdated ) on. Less common are the oxidation states VI ( tellurates (VI ) ) and II ( dihalides ) and -I ( ditellurides ) and I ( monohalides, known only as TeI ).

Hydrogen compounds

Telluride H2Te is a colorless, poisonous gas that with strong acids, for example hydrochloric acid HCl, is formed by reaction of tellurides ( MxTey ). When dissolved in water ( Tellurwasserstoffsäure ) it is acidic, in air, the solution decomposes immediately in water and elemental tellurium.

Oxygen compounds

Tellurium dioxide ( tellurium (IV ) oxide ) TeO2 is a colorless crystalline solid and the most important oxide of tellurium. It results from the combustion of elemental tellurium with air. It is the anhydride of the weakly amphoteric and volatile acid tellurous H2TeO3. Tellurium dioxide exists in an orthorhombic ( tellurite ) and a tetragonal ( paratellurite ) modification that occur in nature as minerals.

Tellurium ( tellurium ( VI) oxide ) TeO3 is a yellow, trigonal / rhombohedral crystallizing solid and the anhydride of orthotelluric H6TeO6. It is produced during the dewatering of the orthotelluric by strong temperature increase. The yellow color comes through electron transfer of oxygen into existence on the tellurium ( " charge-transfer ").

Tellurmonoxid ( tellurium (II ) oxide ) TeO is another, under standard conditions but unstable oxide of tellurium. It is described as a black amorphous solid and reacts with oxygen in moist air to the more stable tellurium dioxide TeO2.

Ditellurpentoxid ( tellurium (IV) tellurium ( VI) oxide ) is mixed with tellurium Te4 - and Te6 cations. It is adjacent tellurium another product in the thermal decomposition of orthotelluric and crystallized in the monoclinic crystal system.

Tellurates are the salts of orthotelluric H6TeO6 and Metatellursäure H2TeO4 with the anions [ TeO6 ] 6 - or [ TeO4 ] 2 -. The salts of the acid tellurous H2TeO3 with the anion [ TeO3 ] 2 - are as tellurates (IV ) (obsolete Tellurite ) refers.

Halogen compounds

Tetrahalides TeX4 with tellurium in the oxidation state IV are widely tellurium halides. These are well known to all halogens (fluorine, chlorine, bromine and iodine). For all compounds are crystalline solids.

Dihalides TEX2 with tellurium in the oxidation state II are known only with chlorine, bromine and iodine, they only exist in the gas phase.

Monohalides TeX exist of tellurium with iodine as Telluriodid TeI. It is the only known thermodynamically stable mono- iodide chalcogen and a dark crystalline solid. Tellurium has in this connection the unusual oxidation state I.

Subhalides contain Te having an oxidation state which is less than I. Stable representatives are Te2I, Te2Br and Te3Cl2.

Hexahalides TeX6 with tellurium in the oxidation state VI are known only as tellurium hexafluoride TeF6 or Tellurpentafluoridchlorid TeF5Cl. Both are colorless gases. Tellurium hexafluoride is the most reactive Chalkogenhexafluorid (besides sulfur hexafluoride SF6 and selenium hexafluoride SeF6 ) is hydrolyzed and the only one in the water.

Furthermore, there are of tellurium in the oxidation state IV in an aqueous solution and the complex compounds [ TeX6 ] 2 - (X = F, Cl, Br, I ) with all the halide ions. With the exception of the hexafluoro complex all others are set up perfectly octahedral and can be precipitated as salts from the solution (for example, yellow ammonium hexachloridotellurat ( IV) ( NH4 ) 2 [ TeCl6 ], red-brown ammonium hexabromidotellurat ( IV) ( NH4) 2 [ TeBr6 ] or black cesium hexaiodidotellurat (IV ) Cs2 [ TeI6 ] ).

Organotellurium compounds

Tellurium is a number of organometallic compounds. However, these are highly unstable and are used in the organic synthesis little. Tellurorganyle as pure compounds of the form R2Te, R2Te2, R4Te and R6Te ( each R is alkyl, aryl ) are known.

In addition, still Diorganotellurdihalogenide R2TeX2 (R = alkyl, aryl, X = F, Cl, Br, I) and Triorganotellurhalogenide R3TeX (R = alkyl, aryl, X = F, Cl, Br, I ) are known.