Sodium telluride is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...

Na₂Te. This

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...

is the

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

of the thermally unstable

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

hydrogen telluride Hydrogen telluride is the inorganic compound with the formula hydrogen, H2telluride (chemistry), Te. A hydrogen chalcogenide and the simplest hydride of tellurium, it is a colorless gas. Although unstable in ambient air, the gas can exist at very ...

, but it is usually prepared by reduction of

tellurium Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally fou ...

with

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

. Na₂Te is a challenging material to handle because it is very sensitive to air. Air oxidizes it initially to polytellurides, which have the formula Na₂Te_x (x > 1), and ultimately Te metal. Samples of Na₂Te, which are colourless when absolutely pure, generally appear purple or dark gray due to the effects of air oxidation.

Synthesis, structure, and solution properties

The synthesis is typically conducted using

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

as the solvent. Na₂Te, like many related compounds with the formula M₂X, adopts the anti

fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs sca ...

structure. Thus, in solid Na₂Te each Te²⁻ ion is surrounded by eight Na⁺ ions and each Na⁺ ion is surrounded by four Te²⁻ ions.Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. . Simple salts of the type M₂X, where X is a monatomic anion, are not typically soluble in any solvent because they have a high

lattice energy In chemistry, the lattice energy is the energy change upon formation of one mole of a crystalline ionic compound from its constituent ions, which are assumed to initially be in the gaseous state. It is a measure of the cohesive forces that bind ...

. Upon addition of water - even moist air - or treatment with alcohols, Te²⁻ protonates: :Na₂Te + H₂O → NaHTe +

NaOH Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali t ...

Because of this reaction, many processes attributed to Na₂Te may involve NaHTe ( CAS # 65312-92-7), which is more soluble and formed readily.

Applications in organic chemistry

Na₂Te finds use in

organic synthesis Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...

, both as a

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

for reductions and as a source of Te in the synthesis of organotellurium compounds."Sodium Telluride" Dittmer, D. C. in Encyclopedia of Reagents for Organic Synthesis 2001. .

Aryl In organic chemistry, an aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl. "Aryl" is used for the sake of abbreviation or generalization, and "Ar" is used as ...

halides are substituted to diaryl tellurides, as illustrated by the synthesis of dinaphthyltelluride: :Na₂Te + 2 C₁₀H₇I → (C₁₀H₇)₂Te + 2 NaI Na₂Te reacts with 1,3- diynes to give the corresponding tellurophene, which are structurally analogous to

thiophene Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its reacti ...

s: :Na₂Te + RC≡C-C≡CR + 2 H₂O → TeC₄R₂H₂ + 2 NaOH As a reducing agent, Na₂Te converts nitro groups to amines and will cleave certain C-X bonds.

References

{{Tellurides Tellurides Sodium compounds Fluorite crystal structure