Zirconium(II) hydride
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3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.028.844 |
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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: | |
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) | |
270 °C | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
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
[edit]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
[edit]- ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–96, ISBN 0-8493-0594-2
- ^ a b c d "Zirconium dihydride".
- ^ a b c "Zirconium hydride | H2Zr | ChemSpider".
- ^ a b c d e f "Zirconium Hydride (ZrH2) (CAS No. 7704-99-6) for Sale | Stanford Advanced Materials".
- ^ a b c d "SAFETY DATA SHEET - Zirconium(II) hydride" (PDF). www.samaterials.com. 2017-04-09.
- ^ 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.