Rhenium pentachloride

Chembox new
ImageName =
IUPACName = Rhenium pentachloride
OtherNames = Rhenium(V) chloride, Rhenium chloride, pentachlororhenium
Section1 = Chembox Identifiers
CASNo = 13596-35-5
Section2 = Chembox Properties
Formula = ReCl₅
MolarMass = 363.471 g/mol
Appearance = red-brown
Density = 4.9 g/cm³, solid
Solubility = Will react to decompose and release HCl (g)
MeltingPt = 220 °C
BoilingPt = N/A
pKa =
Section3 = Chembox Structure
MolShape = Octahedral
CrystalStruct = double hexagonally closed packed
Section7 = Chembox Hazards
ExternalMSDS = [http://www.alfa.com/webapps/ec120w.pgm?itemnum=43294 MSDS]
RSPhrases = R: 36, 37, 38
MainHazards = Highly Air Sensitive, will decompose to form HCl(g)
NFPA-H = 1 | NFPA-R = 0 | NFPA-O = W
Section8 = Chembox Related
OtherAnions = Rhenium hexathiocyanate, Rhenium tetraiodate, Rhenium hexafluoride
Function = compounds
OtherFunctn = Rhenium trichloride, Rhenium tetrachloride, Rhenium hexachloride

Rhenium pentachloride is a compound of rhenium and chlorine. It is a red-brown solid that is very air sensitive and reacts with water to give hydrogen chloride. This compound was first discovered by Geilmann, Wrigge, and Biltz in 1933.cite journal | author = Geilmann, Wilhelm; Wrigge, Friedrich W.; Biltz, Wilhelm. | title = Rheniumpentachlorid | language = German | journal = Z. anorg. allgem. Chem. | year = 1933 | volume = 214 | pages = 244
doi = 10.1002/zaac.19332140304]

tructure and physical properties

Rhenium pentachloride was found to exist as a solid in the form of Re₂Cl₁₀, which has a bridged structure with octahedrally coordinated rhenium atoms and can be formulated Cl₄Re(μ-Cl)₂ReCl₄.cite journal | doi = 10.1107/S0567740868003316 | title = The crystal structure of ReCl5 | year = 1968 | author = Mucker, K. F. | journal = Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry | volume = 24 | pages = 874] It has a melting point of 220 °C and is a paramagnetic molecule. [ [http://www.hbcpnetbase.com/ CRC Handbook Online Edition] ] There has been no report of a boiling point for this compound. Rhenium pentachloride is a double hexagonally closed packed structure.

Preparation

The preparation of this can be found by the chlorination of rhenium at 500 °C. The purification of this material is done through multiple sublimations. The reaction leads to only one side product ReCl₃. Synthesis of ReCl₄ and ReCl₆ must be done by other means.

Uses

Due to its reactivity ReCl₅ is not biologically active. However it can be used to make compounds such as Cp₂ReH, which similar to nickelocene can act as a catalyst to react with olefins. An example of this catalytic activity is in the formation of polymers using ReCl₅. [Ring-opening polymerization of endo and exo-dicyclopentadiene and their 7,8-dihydro derivatives, Hamilton, J.G.; Ivin, K.J.; Rooney, J.J.; "Journal of Molecular Catalysis" 1986 , 36, 115]

This compound is highly reactive and as mentioned previously can react to form lower oxidation states such as rhenium trichloride, which has catalytic activity for a wide variety of applications. An example is the following reaction: [Housecroft, C.E., Sharpe, A.G., "Inorganic Chemistry", 2nd ed., Pearson Education Limited: Essex, England]

:ReCl₅ + 3 Cl₂O → ReO₃Cl + 5 Cl₂

Reactions

Rhenium pentachloride is very air sensitive. Leaving it out overnight in atmosphere will lead to a brown liquid.cite journal | doi = 10.1039/J19700001617 | title = Some reactions of rhenium(V) chloride | year = 1970 | author = Edwards, D. A. | journal = Journal of the Chemical Society A Inorganic Physical Theoretical | pages = 1617]

It can react to form lower oxidation state chlorides such as rhenium trichloride.

:ReCl₅ → ReCl₃

It can also react with neutral and anionic donors to form complexed species.

:ReCl₅ + 6CNS^- → [Re(CNS)₆] ^-

It is also reactive enough to react with solvents such as ammonia:

:ReCl₅ + NH₃ (excess) → ReCl₃(NH₂)₂

References

External links

* [http://www.webelements.com/webelements/compounds/text/Re/Cl5Re1-13596355.html Rhenium Chloride information at webelements]