Rhenium(IV) chloride is the

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

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

comproportionation Comproportionation or symproportionation is a chemical reaction where two reactants containing the same element but with different oxidation numbers, form a compound having an intermediate oxidation number. It is the opposite of disproportionatio ...

rhenium(V) chloride Rhenium pentachloride is an inorganic compound with the formula . This red-brown solid is paramagnetic. Structure and preparation Rhenium pentachloride has a bioctahedral structure and can be described as Cl4Re(μ-Cl)2ReCl4. The (μ-Cl)2 part o ...

and

rhenium(III) chloride 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 ...

. It can also be produced by reduction of

with

antimony trichloride Antimony trichloride is the chemical compound with the formula SbCl3. It is a soft colorless solid with a pungent odor and was known to alchemists as butter of antimony. Preparation Antimony trichloride is prepared by reaction of chlorine with a ...

. :

\mathrm

Tetrachloroethylene Tetrachloroethylene, also known as perchloroethylene or under the systematic name tetrachloroethene, and abbreviations such as perc (or PERC), and PCE, is a chlorocarbon with the formula . It is a non-flammable, stable, colorless and heavy liqu ...

at 120 °C is also effective as a reductant: :

\mathrm

Structure

X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

reveals a polymeric structure. The Re–Re bonding distance is 2.728 Å. Re centers are octahedral, being surrounded by six chloride ligands. Pairs of octahedra share faces. The Re₂Cl₉ subunits are linked by bridging chloride ligands. The structural motif - corner-shared bioctahedra - is unusual in the binary metal halides.

References

{{Chlorides Rhenium(IV) compounds Chlorides Metal halides