Bismuthine
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| Bismuthine | |
|---|---|
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| IUPAC name | bismuthane |
| Other names | bismuth trihydride hydrogen bismuthide |
| Identifiers | |
| CAS number | [] |
| Properties | |
| Molecular formula | BiH3 |
| Molar mass | 212.00 g/mol |
| Appearance | colourless gas |
| Density | 0.008665 g/mL (20 °C) |
| Boiling point |
16.8 °C (extrapolated) |
| Structure | |
| Molecular shape | trigonal pyramidal |
| Related Compounds | |
| Related hydrides | Ammonia Phosphine Arsine Stibine |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Bismuthine is the chemical compound with the formula BiH3. As the heaviest analogue of ammonia, BiH3 is unstable, decomposing to bismuth metal well below 0 °C. In fact, the compound has only been characterized (by infra-red spectroscopy and microwave spectroscopy) as a component of a mixture. This compound is also predicted to have a pyramidal structure with H-Bi-H angles of 90°. Bismuthines also describes a family of organobismuth(III) species; for example Bi(CH3)3 is trimethylbismuthine.
Contents |
[edit] Preparation and properties
BiH3 is prepated by the redistribution of methylbismuthine BiH2Me:[1]
- 3 BiH2Me → 2 BiH3 + BiMe3
The required BiH2Me, which is also thermally unstable, is generated by reduction of methylbismuth dichloride, BiCl2Me with LiAlH4.[2]
As suggested by the behavior of SbH3), BiH3 is unstable with respect to its elements. The gas decomposes according to the following equation:
-
- 2 BiH3 → 3 H2 + 2 Bi
- ΔHf'
ogas = −278 kJ/mol
The methodology used for detection of arsenic ("Marsh Test") can also be used to detect BiH3. This test relies on the thermal decomposition of these trihydrides to the metallic mirrors of metallic As, Sb, and Bi. These deposits can be further distinguished by their distinctive solubility characteristics: As dissolves in NaOCl, Sb dissolves in ammonium polysulfide, and Bi resists both reagents.[1]
[edit] Uses and safety considerations
The low stability of BiH3 preclude significant hazards and technical applications.
[edit] References
- ^ a b Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001.ISBN 0-12-352651-5.
- ^ Jerzembeck, W.; Bürger, H.; Constantin, L.; Margulès, L.; Demaison, J.; Breidung, J.; Thiel, W. "Bismuthine BiH3: Fact or Fiction? High-Resolution Infrared, Millimeter-Wave, and Ab Initio Studies" Angewandte Chemie International Edition 2002, Volume 41, pages 2550-2552. DOI:10.1002/1521-3773
