Chemistry:Ruthenium(III) bromide

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Ruthenium(III) bromide
Ruthenium(III)-bromide-xtal-chain-3D-bs-17.png
Ruthenium(III)-bromide-xtal-3x3x3-b-3D-bs-17.png
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 237-829-4
UNII
Properties
RuBr3
Molar mass 340.782 g/mol
Structure
orthorhombic[1]
Pmmn, No. 59
octahedral
Hazards
GHS pictograms GHS05: Corrosive
GHS Signal word Danger
H314
P260, P264, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P363, P405, P501
Related compounds
Other anions
Ruthenium(III) chloride
Other cations
Rhodium(III) bromide
Iron(III) bromide
Molybdenum(III) bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Ruthenium(III) bromide is a chemical compound of ruthenium and bromine with the formula RuBr3. It is a dark brown solid that decomposes above 400 °C.[2]

Preparation

Ruthenium(III) bromide can be prepared by the reaction of ruthenium metal with bromine at high temperature and pressure (720 K and 20 bar):[3]

2 Ru + 3 Br2 → 2 RuBr3

Structure

The crystal structures of ruthenium(III) bromide contain parallel (RuBr3) columns. The compound undergoes a phase transition around 384 K (111 °C) from an ordered orthorhombic structure in space group Pnmm with alternating long and short Ru-Ru distances to a disordered hexagonal TiI3-like structure in space group P63/mcm with (on average) equal Ru-Ru distances.[1] In the disordered polymorph, the Ru-Ru distances are not believed to actually be equal but appear so due to a random distribution of two distinct column conformations. Both polymorphs consist of hexagonally close-packed bromide ions.[4]

References

  1. 1.0 1.1 Hillebrecht, H.; Ludwig, T.; Thiele, G. (2004). "About Trihalides with TiI3 Chain Structure: Proof of Pair Forming of Cations in β-RuCl3 and RuBr3 by Temperature Dependent Single Crystal X-ray Analyses". Zeitschrift für Anorganische und Allgemeine Chemie 630 (13–14): 2199–2204. doi:10.1002/zaac.200400106. 
  2. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1082-1084. ISBN 978-0-08-037941-8. 
  3. Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. p. 779. ISBN 978-0-13-175553-6. 
  4. Merlino, S.; Labella, L.; Marchetti, F.; Toscani, S. (2004). "Order−Disorder Transformation in RuBr3 and MoBr3: A Two-Dimensional Ising Model". Chem. Mater. 16 (20): 3895–3903. doi:10.1021/cm049235q.