Rhenium trichloride

Rhenium trichloride
IUPAC name

Rhenium(III) chloride
Other names

Rhenium trichloride
Identifiers
CAS number 13569-63-6
Properties
Molecular 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 Re2O3.xH2O.
Structure
Crystal structure Rhombohedral, hR72
Space group R-3m, No. 166
Molecular shape (trimeric solid and in solution)
(dimeric in acetic acid)
Hazards
MSDS External MSDS
Main hazards Corrosive (C)
Related compounds
Other anions Rhenium tribromide
Rhenium triiodide
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Rhenium trichloride (ReCl3) is a compound of rhenium and chlorine. It was first discovered in 1932 by Geilnann, Wriuce, and Biltz.[1]

Contents

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 C3v symmetry.[2]

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.[2]

Chemical properties

Rhenium trichloride prepared from rhenium pentachloride without further treatment is chemically reactive, but if it is vacuum sublimed at 500 °C, then it becomes comparatively unreactive. However, x-ray diffraction tests show no observable difference in structure between the untreated and vacuum sublimed material.[2]

The heat of oxidation according to the equation,

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

is 190.7 ± 0.2 kcal/mol.[2]

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,[2] or the heating of Re2(O2CCH3)4Cl2 under HCl gas.[3]

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.[4]

References

  1. ^ Geilnann, W.; Wriuce, F. W.; Biltz. W.: Nachr. Ges. Wiss. Gottingen 1932, 579.
  2. ^ a b c d e Colton, R. Chemistry of rhenium and technetium. London: Interscience Publishers. 1965.
  3. ^ Lincoln R.; Wilkinson, G. (1980). "Trirhenium Nonachloride". Inorg. Synth.. Inorganic Syntheses 20: 44. doi:10.1002/9780470132517.ch12. ISBN 9780470132517. 
  4. ^ Hamon, J-R, Astruc, D. (1989). "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". Organometallics 8 (9): 2243–2247. doi:10.1021/om00111a022.