Zirconium(II) hydride

For the hydrogen-zirconium system, see Zirconium hydride.
Zirconium(II) hydride[1]
Names
IUPAC name
Zirconium(II) hydride[2][3]
Other names
  • Hydride;zirconium(2+)[2]
  • Zirconium(2+) dihydride[2][3]
  • Zirconium dihydride[2][3]
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.028.844 Edit this at Wikidata
EC Number
  • 231-727-3
RTECS number
UNII
  • InChI=1S/Zr.2H
    Key: QSGNKXDSTRDWKA-UHFFFAOYSA-N
  • [ZrH2]
  • [H-].[H-].[Zr+2]
Properties
ZrH2
Molar mass 93.240 g/mol
Appearance Grey tetragonal crystals or dark gray to black metallic powder[4][5]
Odor Odorless[4]
Density 5.60 g/cm3
Melting point 800°C (decomposes)
Insoluble[5]
Solubility Soluble in HF
Structure
tetragonal
dihedral (C2v)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Skin irritation, eye irritation, flammable[5]
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H228, H315, H319, H335
P210, P240, P241, P261, P264, P271, P280, P302+P352, P304+P340+P312, P305+P351+P338, P332+P313, P337+P313, P362, P370+P378, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
3
1
270 °C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Zirconium(II) hydride is a molecular chemical compound with the chemical formula ZrH2. It is a grey crystalline solid or dark gray to black powder.[4][5] It has been prepared by laser ablation and isolated at low temperature.[6]

Zirconium(II) hydride has repeatedly been the subject of Dirac–Hartree–Fock relativistic calculation studies, which investigate the stabilities, geometries, and relative energies of hydrides of the formula MH4, MH3, MH2, or MH.

Zirconium(II) hydride has a dihedral (C2v) structure. In zirconium(II) hydride, the formal oxidation states of zirconium and hydrogen are +2 and −1, respectively, because the electronegativity of zirconium is lower than that of hydrogen. The stability of metal hydrides with the formula MH2 (M = Ti, Zr, Hf) decreases from Ti to Hf.

Uses

Zirconium(II) hydride is used as a thermal neutron moderator in nuclear reactors and as a material for neutron reflectors in fast reactors.[4]

Zirconium(II) hydride in the form of a powder is used in powder metallurgy as a hydrogenation catalyst, vacuum tube getter, foaming agent in the production of metal foams and as a reducing agent.[4]

References

  1. ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–96, ISBN 0-8493-0594-2
  2. ^ a b c d "Zirconium dihydride".
  3. ^ a b c "Zirconium hydride | H2Zr | ChemSpider".
  4. ^ a b c d e f "Zirconium Hydride (ZrH2) (CAS No. 7704-99-6) for Sale | Stanford Advanced Materials".
  5. ^ a b c d "SAFETY DATA SHEET - Zirconium(II) hydride" (PDF). www.samaterials.com. 2017-04-09.
  6. ^ Chertihin, George V.; Andrews, Lester (1995). "Reactions of laser-ablated Zr and Hf atoms with hydrogen. Matrix infrared spectra of the MH, MH2, MH3, and MH4 molecules". The Journal of Physical Chemistry. 99 (41): 15004–15010. doi:10.1021/j100041a014. ISSN 0022-3654.

See also