 | |
 Beryllium Boron Hydrogen | |
| Names | |
|---|---|
| IUPAC name Beryllium borohydride | |
| Other names Beryllium tetrahydroborate(1−), Beryllium tetrahydroborate(III) | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| UNII | |
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| Properties | |
| Be[BH4]2 | |
| Molar mass | 38.70 g·mol−1 |
| Appearance | white crystals |
| Density | 0.604 g/cm3 |
| Melting point | 91.3 °C (196.3 °F; 364.4 K) |
| Boiling point | 123 °C (253 °F; 396 K) decomposes |
| reacts | |
| Solubility | soluble inbenzene,diethyl ether |
| Structure | |
| tetragonal | |
| I41cd, No. 110 | |
| Thermochemistry | |
Std enthalpy of formation(ΔfH⦵298) | −108 kJ/mol |
| Hazards | |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 0.002 mg/m3 C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be)[1] |
REL (Recommended) | Ca C 0.0005 mg/m3 (as Be)[1] |
IDLH (Immediate danger) | Ca [4 mg/m3 (as Be)][1] |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Beryllium borohydride is aninorganic compound with thechemical formulaBe[BH4]2.[2]
Beryllium borohydride is formed by the reaction ofberyllium hydride withdiborane in anether solution.
It can also be formed by the reaction ofberyllium chloride andlithium borohydride in a sealed tube at 120 °C:[2]
The chemical formula of beryllium borohydride can be written asBe2+([BH4]−)2. Thecrystal structure is made up of a helicalpolymer ofBH4Be andBH4 structure units.[2][3] Theborohydride ions,[BH4]−, adopt atetrahedral geometry.[3] Beryllium is 6-coordinate and adopts a distortedtrigonal prismatic geometry.[2]
The purestberyllium hydride is obtained by the reaction oftriphenylphosphine,PPh3, with beryllium borohydride,Be[BH4]2 at 180 °C:[2]
