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Trirhenium nonachloride

Names
IUPAC name Rhenium(III) chloride
Other names Rhenium trichloride
Identifiers
CAS Number	13569-63-6
ECHA InfoCard	100.033.610
CompTox Dashboard (EPA)	DTXSID8065537
Properties
Chemical formula	ReCl3
Molar mass	292.57 g/mol
Appearance	red, crystalline, nonvolatile solid
Density	4800 kg/m³
Melting point	N/A
Boiling point	500 °C (decomposes)
Solubility in water	hydrolyzes to form Re2O3xH2O.
Structure
Crystal structure	Rhombohedral, hR72
Space group	R-3m, No. 166
Molecular shape	(trimeric solid and in solution) (dimeric in acetic acid)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Corrosive (C)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

Rhenium trichloride (ReCl₃) is a compound of rhenium and chlorine. It was first discovered in 1932 by Geilnann, Wriuce, and Biltz.

Structure and physical properties

The crystal structure of rhenium trichloride consists of well-defined Re₃Cl₉ units that are connected by chlorine atom bridges. The Re₃Cl₉ unit structure also applies to rhenium trichloride dissolved in a variety of solvents, with the only possible exception being the dimer structure when dissolved in acetic acid. The Re₃Cl₉ crystal structure has C_3v symmetry.

Rhenium trichloride is comparatively non-volatile but produces a green vapour during strong heating. It may have a very small temperature-independent paramagnetism, but the susceptibility is ambiguous.

Chemical properties

Rhenium trichloride prepared from rhenium pentachloride without further treatment is chemically reactive, but if it is vacuum sublimed at 500C, then it becomes comparatively unreactive. However, x-ray diffraction tests show no observable difference in structure between the untreated and vacuum sublimed material.

The heat of oxidation according to the equation,

ReCl₃(s) + 4OH + 2OCl → ReO₄ + 2H₂O + 5Cl

is 190.7 ± 0.2 kcal/mol.

Preparation

Rhenium trichloride is most efficiently prepared by the thermal decomposition of rhenium pentachloride in nitrogen. Other methods include reacting sulphuryl chloride with rhenium powder with or without the addition of aluminium chloride, the thermal decomposition of salts of hexachlororhenic(IV) acid, or the heating of Re₂(O₂CCH₃)₄Cl₂ under HCl gas.

Uses

Rhenium trichloride is used as a starting material for synthesis of rhenium complexes. ReCl₃ can react with peralkylated benzene-metal complexes that act as electron reservoirs.

References

1. Geilnann, W.; Wriuce, F. W.; Biltz. W.: Nachr. Ges. Wiss. Gottingen 1932, 579.
2. ^ Colton, R. Chemistry of rhenium and technetium. London: Interscience Publishers. 1965.
3. Lincoln R.; Wilkinson, G. (1980). "Trirhenium Nonachloride". Inorg. Synth. 20: 44. doi:10.1002/9780470132517.ch12.{{cite journal}}: CS1 maint: multiple names: authors list (link)
4. Hamon, J-R, Astruc, D. (1989). "Organometallic electron reservoirs. 38. Influence of steric bulk on Fischer-type syntheses of peralkylated electron-reservoir sandwiches : cleavage of alkyl groups and mechanistic implications". Organometallics. 8 (9): 2243–2247. doi:10.1021/om00111a022.{{cite journal}}: CS1 maint: multiple names: authors list (link)

• Rhenium compounds
• Chlorides