Boron triiodide is a chemical compound of boron and iodine with chemical formula BI3. It has a trigonal planar molecular geometry.

Boron triiodide[1]
Names
IUPAC name
triiodoborane
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.492 Edit this at Wikidata
RTECS number
  • ED7400000
  • InChI=1S/BI3/c2-1(3)4 checkY
    Key: YMEKEHSRPZAOGO-UHFFFAOYSA-N checkY
  • InChI=1/BI3/c2-1(3)4
    Key: YMEKEHSRPZAOGO-UHFFFAOYAR
  • IB(I)I
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
71 J/mol K
200 J/mol K
-37.2 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
0
0
Flash point −18 °C (0 °F; 255 K)
Safety data sheet (SDS) Sigma-Aldrich
Related compounds
Related compounds
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

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Boron 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

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In 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

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Boron triiodide can be used to produce other chemical compounds and as a catalyst (for example in coal liquefaction).[6]

References

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  1. ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  2. ^ a b Handbuch der präparativen anorganischen Chemie. 2 (3., umgearb. Aufl ed.). Stuttgart: Enke. 1978. ISBN 978-3-432-87813-3.
  3. ^ "Beiträge zur Chemie der Bor-Stickstoff-Verbindungen" (PDF). Archived from the original (PDF) on 2010-09-23. Retrieved 2023-09-19.
  4. ^ 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.
  5. ^ 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.
  6. ^ "Kohleverflüssigung – Innovations Report". www.innovations-report.de. Retrieved 2023-09-19.
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