Rhenium trichloride

Chembox new
ImageFile =
ImageName = Rhenium Trichloride Crystal Structure
IUPACName = Rhenium(III) chloride
OtherNames = Rhenium trichloride
Section1 = Chembox Identifiers
CASNo = 13569-63-6
Section2 = Chembox Properties
Formula = ReCl₃
MolarMass = 292.57 g/mol
Appearance = red, crystalline, nonvolatile solid
Density = 4800 kg/m³
Solubility = hydrolyzes to form Re₂O₃^.xH₂O.
MeltingPt = N/A
BoilingPt = 500 °C (decomposes)
Section3 = Chembox Structure
MolShape = (trimeric solid and in solution)
(dimeric in acetic acid)

Coordination = Octahedral
CrystalStruct = Double Layered Rhombohedral
Dipole =
Section7 = Chembox Hazards
ExternalMSDS = External MSDS
MainHazards = Corrosive (C)
Section8 = Chembox Other
OtherAnions = Rhenium tribromide
Rhenium triiodide
OtherCpds =

Rhenium trichloride (ReCl₃) is a compound of rhenium and chlorine. It was first discovered in 1932 by Geilnann, Wriuce, and Biltz. [Geilnann, W.; Wriuce, F. W.; Biltz. W.: Nachr. Ges. Wiss. Gottingen 1932, 579.]

tructure 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.Colton, R. Chemistry of rhenium and technetium. London: Interscience Publishers. 1965.]

Chemical properties

Rhenium trichloride prepared from rhenium pentachloride without further treatment is chemically reactive, but if it is vacuum sublimed at 500^oC, 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. [cite journal | author = Lincoln R.; Wilkinson, G. | journal = Inorg. Synth. | title = Trirhenium Nonachloride | year = 1980 | volume = 20 | pages = 44
doi = 10.1002/9780470132517.ch12]

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.cite journal | author = Hamon, J-R, Astruc, D. | journal = Organometallics | title = Organometallic electron reservoirs. 38. Influence of steric bulk on Fischer-type syntheses of peralkylated electron-reservoir sandwiches [FeCp*(arene)] ⁺: cleavage of alkyl groups and mechanistic implications | year = 1989 | volume = 8 | issue = 9 | pages = 2243–2247
doi = 10.1021/om00111a022]

References