Rhenium pentachloride is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

and rhenium. The compound has the formula Re₂Cl₁₀ but it is usually referred to as rhenium pentachloride. It is a red-brown solid.

Structure and preparation

Rhenium pentachloride has a bioctahedral structure and can be formulated as Cl₄Re(μ-Cl)₂ReCl₄. The Re-Re distance is 3.74 Å. The motif is similar to that seen for

tantalum pentachloride Tantalum(V) chloride, also known as tantalum pentachloride, is an inorganic compound with the formula TaCl5. It takes the form of a white powder and is commonly used as a starting material in tantalum chemistry. It readily hydrolyzes to form tantal ...

. This compound was first prepared in 1933, a few years after the discovery of rhenium. The preparation involves chlorination of rhenium at temperatures up to 900 °C. The material can be purified by sublimation. ReCl₅ is one of the most oxidized binary chlorides of Re. It does not undergo further chlorination. ReCl₆ has been prepared from

rhenium hexafluoride Rhenium hexafluoride, also rhenium(VI) fluoride, (ReF6) is a compound of rhenium and fluorine and one of the seventeen known binary hexafluorides. Synthesis Rhenium hexafluoride is made by combining rhenium heptafluoride with additional rheni ...

Rhenium heptafluoride Rhenium heptafluoride is the compound with the formula ReF7. It is a yellow low melting solid and is the only thermally stable metal heptafluoride. It has a distorted pentagonal bipyramidal structure similar to IF7, which was confirmed by neutron ...

is known but not the heptachloride.

Uses and reactions

It degrades in air to a brown liquid. Although rhenium pentachloride has no commercial applications, it is of historic significance as one of the early catalysts for olefin metathesis. Reduction gives

trirhenium nonachloride Trirhenium nonachloride is a compound with the formula ReCl3, sometimes also written Re3Cl9. It is a dark red hygroscopic solid that is insoluble in ordinary solvents. The compound is important in the history of inorganic chemistry as an early ex ...

. Oxygenation affords the Re(VII) oxychloride: :ReCl₅ + 3 Cl₂O → ReO₃Cl + 5 Cl₂ Comproportionation of the penta- and trichloride gives

rhenium tetrachloride Rhenium(IV) chloride is the inorganic compound with the formula ReCl4. This black solid is of interest as a binary phase but otherwise is of little practical value. A second polymorph of ReCl4 is also known. Preparation ReCl4 can be prepared by ...

References

External links

Rhenium Chloride information at webelements
{{Chlorides Rhenium compounds Chlorides Metal halides Substances discovered in the 1930s