Pentamethylbismuth
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| Names | |
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| Preferred IUPAC name
Pentamethyl-λ5-bismuthane | |
| Identifiers | |
3D model (
JSmol ) |
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PubChem CID
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| UNII | |
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| Properties | |
| C5H15Bi | |
| Molar mass | 284.155 g·mol−1 |
| Appearance | blue-violet solid |
| Related compounds | |
Related compounds
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Trimethylbismuth Pentamethylarsenic Pentamethylantimony Pentamethyltantalum Pentaphenylbismuth |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pentamethylbismuth (or pentamethylbismuthorane
Production
Pentamethylbismuth is produced in a two step process. First, trimethylbismuth is reacted with sulfuryl chloride to yield dichloro trimethylbismuth, which is then reacted with two equivalents of methyllithium dissolved in ether.[4] The blue solution is cooled to −110 °C to precipitate the solid product.
- Bi(CH3)3 + SO2Cl2 → Bi(CH3)3Cl2 + SO2
- Bi(CH3)3Cl2 + 2LiCH3 → Bi(CH3)5 + 2LiCl
Properties
At -110 °C, Bi(CH3)5 is a blue-violet solid. The methyl groups are arranged in a trigonal bipyramid, and the bond-lengths of methyl with bismuth are all the same. However, the molecule is not rigid, as can be determined from the nuclear magnetic resonance spectrum that shows all methyl groups are equivalent.[4] It is stable as a solid, but in the gas phase, when heated or in solution decomposes to trimethylbismuth.[3][4] The colour is unusual for bismuth or other hypervalent
Reactions
If excess methyllithium is used in production, an orange hexamethylbismuth salt, LiBi(CH3)6, is formed.[6] This is unusual as very few elements can form bonds with six organic groups.[4]
References
- ISBN 9780080523408.
- ISBN 3-540-11907-8.
- ^ .
- ^ .
- PMID 28168144.
- .
Extra reading
- Gagnon, Alexandre; Dansereau, Julien; Le Roch, Adrien (2 March 2017). "Organobismuth Reagents: Synthesis, Properties and Applications in Organic Synthesis". Synthesis. 49 (8): 1707–1745. S2CID 102471505.