Rhenium(IV) chloride is the

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 ...

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 synproportionation 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 disproportionation. ...

rhenium(V) chloride Rhenium pentachloride is an inorganic compound of chlorine 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 ...

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 e ...

. 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 an ...

. :

\mathrm

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

\mathrm

Structure

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

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 compounds Chlorides Metal halides