Beryllium hydride
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| Names | |
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| Other names
Beryllium dihydride
Beryllium hydride Beryllane |
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| Identifiers | |
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3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
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PubChem CID
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| Properties | |
| BeH2 | |
| Molar mass | 11.03 g mol−1 |
| Appearance | amorphous white solid |
| Density | 0.65 g/cm3 |
| Melting point | 250 °C (482 °F; 523 K) decomposes |
| decomposes | |
| Solubility | insoluble in diethyl ether, toluene |
| Thermochemistry | |
| 30.124 J/mol K | |
| Hazards | |
| US health exposure limits (NIOSH): | |
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PEL (Permissible)
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TWA 0.002 mg/m3 C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be) |
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REL (Recommended)
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Ca C 0.0005 mg/m3 (as Be) |
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IDLH (Immediate danger)
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Ca [4 mg/m3 (as Be)] |
| Related compounds | |
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Other cations
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lithium hydride, calcium hydride, boron hydrides |
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Related compounds
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beryllium fluoride |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |
Beryllium hydride (systematically named beryllium dihydride) is an inorganic compound with the chemical formula (BeH
2)n (also written ([BeH
2])n or BeH
2). This alkaline earth hydride is a colourless solid that is insoluble in solvents that do not decompose it. Unlike the ionically bonded hydrides of the heavier Group 2 elements, beryllium hydride is covalently bonded (three-center two-electron bond).
Unlike the other group 2 metals, beryllium does not react with hydrogen. Instead, BeH2 is prepared from preformed beryllium(II) compounds. It was first synthesised in 1951 by treating dimethylberyllium, Be(CH3)2, with lithium aluminium hydride, LiAlH4.
Purer BeH2 forms from the pyrolysis of di-tert-butylberyllium, Be(C(CH3)3)2 at 210 °C.
A route to highly pure samples involve the reaction of triphenylphosphine, PPh3, with beryllium borohydride, Be(BH4)2:
BeH2 is usually formed as an amorphous white solid, but a hexagonal crystalline form with a higher density (~0.78 g cm−3) was reported, prepared by heating amorphous BeH2 under pressure, with 0.5-2.5% LiH as a catalyst.
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