Boron triiodide is a chemical compound of boron and iodine with chemical formula BI3. It has a trigonal planar molecular geometry.
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| IUPAC name
triiodoborane
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| Identifiers | |||
3D model (JSmol)
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| ChemSpider | |||
| ECHA InfoCard | 100.033.492 | ||
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |||
| BI3 | |||
| Molar mass | 391.52 g/mol | ||
| Appearance | crystalline solid | ||
| Density | 3.35 g/cm3 (50 °C) | ||
| Melting point | 49.9 °C (121.8 °F; 323.0 K) | ||
| Boiling point | 210 °C (410 °F; 483 K) | ||
| soluble,hydrolysis | |||
| Solubility | soluble in CCl4, CS2, benzene, chloroform | ||
| 0D | |||
| Structure | |||
| hexagonal | |||
| Thermochemistry | |||
Heat capacity (C)
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71 J/mol K | ||
Std molar
entropy (S⦵298) |
200 J/mol K | ||
Std enthalpy of
formation (ΔfH⦵298) |
-37.2 kJ/mol | ||
| Hazards | |||
| NFPA 704 (fire diamond) | |||
| Flash point | −18 °C (0 °F; 255 K) | ||
| Safety data sheet (SDS) | Sigma-Aldrich | ||
| Related compounds | |||
Related compounds
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Boron trifluoride Boron trichloride Boron tribromide | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation
editBoron triiodide can be prepared by the reaction of boron with iodine at 209.5 °C or 409.1 °F.[citation needed] It can also be prepared by reacting hydroiodic acid with boron trichloride:
- 3HI + BCl3 → BI3 + 3HCl (reaction requires high temperature)
Another method is by reacting lithium borohydride with iodine. As well as boron triiodide, this reaction also produces lithium iodide, hydrogen and hydrogen iodide:[2]
- 3LiBH4 + 8I2 → 3LiI + 3BI3 + 4H2 + 4HI
Properties
editIn its pure state, boron triiodide forms colorless, otherwise reddish, shiny, air and hydrolysis-sensitive[3] crystals, which have a hexagonal crystal structure (a = 699.09 ± 0.02 pm, c = 736.42 ± 0.03 pm, space group P63/m (space group no. 176)).[4] Boron triiodide is a strong Lewis acid and soluble in carbon disulfide.[2]
Boron triiodide reacts with water and decomposes to boric acid and hydriodic acid:
- BI3 + 3H2O ⇌ B(OH)3 + 3HI
Its dielectric constant is 5.38 and its heat of vaporization is 40.5 kJ/mol. At extremely high pressures, BI3 becomes metallic at ~23 GPa and is a superconductor above ~27 GPa.[5]
Applications
editBoron triiodide can be used to produce other chemical compounds and as a catalyst (for example in coal liquefaction).[6]
References
edit- ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
- ^ a b Handbuch der präparativen anorganischen Chemie. 2 (3., umgearb. Aufl ed.). Stuttgart: Enke. 1978. ISBN 978-3-432-87813-3.
- ^ "Beiträge zur Chemie der Bor-Stickstoff-Verbindungen" (PDF). Archived from the original (PDF) on 2010-09-23. Retrieved 2023-09-19.
- ^ Albert, Barbara; Schmitt, Konny (May 2001). "Die Kristallstruktur von Bortriiodid, BI3". Zeitschrift für anorganische und allgemeine Chemie (in German). 627 (5): 809–810. doi:10.1002/1521-3749(200105)627:5<809::AID-ZAAC809>3.0.CO;2-J. ISSN 0044-2313.
- ^ Hamaya, Nozomu; Ishizuka, Miyuki; Onoda, Suzue; Guishan, Jiang; Ohmura, Ayako; Shimizu, Katsuya (2010). "Pressure-induced phase transition, metallization, and superconductivity in boron triiodide". Physical Review B. 82 (9): 094506. Bibcode:2010PhRvB..82i4506H. doi:10.1103/PhysRevB.82.094506.
- ^ "Kohleverflüssigung – Innovations Report". www.innovations-report.de. Retrieved 2023-09-19.
External links
edit- MSDS Archived 2011-07-23 at the Wayback Machine (link is broken)