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| Names | |
|---|---|
| Systematic IUPAC name Beryllium iodide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.029.199 |
| UNII | |
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| Properties | |
| BeI2 | |
| Molar mass | 262.82112 g·mol−1 |
| Appearance | colorless needle-like crystals |
| Density | 4.325 g/cm3 |
| Melting point | 480 °C (896 °F; 753 K) |
| Boiling point | 590 °C (1,094 °F; 863 K)[1] |
| reacts with water[1] | |
| Solubility | Slightly soluble inCS2 Soluble inethanol,diethyl ether[2] |
| Structure | |
| orthorhombic | |
| Thermochemistry | |
| 71.14 J/(mol·K) | |
Std molar entropy(S⦵298) | 130 J/(mol·K) |
Std enthalpy of formation(ΔfH⦵298) | −192.62 kJ/mol |
Gibbs free energy(ΔfG⦵) | −210 kJ/mol |
Std enthalpy of combustion(ΔcH⦵298) | 19 kJ/mol |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | seeBerylliosis |
| NFPA 704 (fire diamond) | |
| 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)[3] |
REL (Recommended) | Ca C 0.0005 mg/m3 (as Be)[3] |
IDLH (Immediate danger) | Ca [4 mg/m3 (as Be)][3] |
| Related compounds | |
Otheranions | |
Othercations | |
Related compounds | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Beryllium iodide is aninorganic compound with thechemical formulaBeI2. It is ahygroscopic white solid. TheBe2+ cation, which is relevant to salt-like BeI2, is characterized by the highest knowncharge density (Z/r = 6.45), making it one of thehardest cations and a very strongLewis acid.[4]
Beryllium iodide can be prepared by reactingberyllium metal with elementaliodine at temperatures of 500 °C to 700 °C:[1]
When the oxidation is conducted on an ether suspension of elemental Be, one obtains colorless dietherate:[5]
The same dietherate is obtained by suspending beryllium iodide in diethyl ether:[5]
This ether ligands inBeI2(O(C2H5)2)2 can be displaced by otherLewis bases.
Beryllium iodide reacts withfluorine givingberyllium fluoride andfluorides of iodine, withchlorine givingberyllium chloride, and withbromine givingberyllium bromide.
Two forms (polymorphs) ofBeI2 are known. Both structures consist tetrahedralBe2+ centers interconnected by doubly bridging iodide ligands. One form consist of edge-sharing polytetrahedra. The other form resembleszinc iodide with interconnected adamantane-like cages.[6]
Beryllium iodide can be used in the preparation of high-purity beryllium by the decomposition of the compound on a hottungsten filament.
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