Rhenium pentachloride

Rhenium pentachloride is an inorganic compound with the formula Re₂Cl₁₀. This red-brown solid^[3] is paramagnetic.^[4]

Rhenium pentachloride

Names
IUPAC name Rhenium pentachloride
Other names Rhenium(V) chloride, Rhenium chloride, pentachlororhenium
Identifiers
CAS Number	13596-35-5 Y
3D model (JSmol)	monomer: Interactive image dimer: Interactive image
ChemSpider	75428
ECHA InfoCard	100.033.660
EC Number	237-042-6
PubChem CID	83602
CompTox Dashboard (EPA)	DTXSID1065552
InChI InChI=1S/5ClH.Re/h5*1H;/q;;;;;+5/p-5 Key: XZQYTGKSBZGQMO-UHFFFAOYSA-I InChI=1/5ClH.Re/h5*1H;/q;;;;;+5/p-5/rCl5Re/c1-6(2,3,4)5 Key: XZQYTGKSBZGQMO-PXGBCINVAP
SMILES monomer: Cl[Re](Cl)(Cl)(Cl)Cl dimer: Cl[Re-]1(Cl)(Cl)(Cl)[Cl+][Re-]([Cl+]1)(Cl)(Cl)(Cl)Cl
Properties
Chemical formula	ReCl5
Molar mass	363.471 g/mol
Appearance	red-brown
Density	4.9 g/cm3, solid
Melting point	220 °C (428 °F; 493 K)
Boiling point	N/A
Solubility in water	Will react to decompose and release HCl (g)
Magnetic susceptibility (χ)	+1225.0·10−6 cm3/mol
Structure
Crystal structure	Monoclinic, mP48; a = 0.924 nm, b = 1.154 nm, c = 1.203 nm, α = 90°, β = 109.1°, γ = 90° [1]
Space group	P21/c, No. 14
Molecular shape	Octahedral
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	releases HCl upon hydrolysis
GHS labelling:[2]
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	1 0 W
Safety data sheet (SDS)	MSDS
Related compounds
Other anions	Rhenium pentafluoride
Other cations	Osmium pentachloride
Related Rhenium chlorides	Trirhenium nonachloride Rhenium tetrachloride Rhenium hexachloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Structure and preparation

Rhenium pentachloride has a bioctahedral structure and can be described as Cl₄Re(μ-Cl)₂ReCl₄. The (μ-Cl)₂ part of this formula indicates that two chloride ligands are bridging ligands, i.e. they connect to two Re atoms. The Re-Re distance is 3.74 Å.^[1] The motif is similar to that seen for tantalum pentachloride.

This compound was first prepared in 1933,^[5] a few years after the discovery of rhenium. The preparation involves chlorination of rhenium at temperatures up to 900 °C.^[3] 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.^[6] Rhenium heptafluoride is known but not the heptachloride.^[7]

Uses and reactions

It degrades in air to a brown liquid.^[8]

Although rhenium pentachloride has no commercial applications, it is of historic significance as one of the early catalysts for olefin metathesis.^[9] Reduction gives trirhenium nonachloride.

Oxygenation affords the Re(VII) oxychloride:^[10]

ReCl₅ + 3 Cl₂O → ReO₃Cl + 5 Cl₂

Comproportionation of the penta- and trichloride gives rhenium tetrachloride.