Decaborane
Decaborane, also called decaborane(14), is the inorganic compound with the chemical formula B10H14. It is classified as a borane and more specifically a boron hydride cluster. This white crystalline compound is one of the principal boron hydride clusters, both as a reference structure and as a precursor to other boron hydrides. It is toxic and volatile, giving off a foul odor, like that of burnt rubber or chocolate.
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| Names | |
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| Other names
decaborane
decaboron tetradecahydride | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.037.904 |
| EC Number |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| B10H14 | |
| Molar mass | 122.22 g/mol |
| Appearance | White crystals |
| Odor | bitter, chocolate-like or burnt rubber[1] |
| Density | 0.94 g/cm3[1] |
| Melting point | 97–98 °C (207–208 °F; 370–371 K) |
| Boiling point | 213 °C (415 °F; 486 K) |
| Solubility in other solvents | Slightly, in cold water. [1] |
| Vapor pressure | 0.2 mmHg[1] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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may ignite spontaneously on exposure to air[1] |
| GHS labelling: | |
   
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| Danger | |
| H228, H301, H310, H316, H320, H330, H335, H336, H370, H372 | |
| P210, P240, P241, P260, P262, P264, P270, P271, P280, P284, P301+P310, P302+P350, P304+P340, P305+P351+P338, P307+P311, P310, P312, P314, P320, P321, P330, P332+P313, P337+P313, P361, P363, P370+P378, P403+P233, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 80 °C; 176 °F; 353 K |
| 149 °C (300 °F; 422 K) | |
| Lethal dose or concentration (LD, LC): | |
LC50 (median concentration)
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276 mg/m3 (rat, 4 hr) 72 mg/m3 (mouse, 4 hr) 144 mg/m3 (mouse, 4 hr)[2] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 0.3 mg/m3 (0.05 ppm) [skin][1] |
REL (Recommended)
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TWA 0.3 mg/m3 (0.05 ppm) ST 0.9 mg/m3 (0.15 ppm) [skin][1] |
IDLH (Immediate danger)
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15 mg/m3[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Decaborane, also called decaborane(14), is the inorganic compound with the chemical formula B10H14. It is classified as a borane and more specifically a boron hydride cluster. This white crystalline compound is one of the principal boron hydride clusters, both as a reference structure and as a precursor to other boron hydrides. It is toxic and volatile, giving off a foul odor, like that of burnt rubber or chocolate.
Handling, properties and structure
[edit]The physical characteristics of decaborane(14) resemble those of naphthalene and anthracene, all three of which are volatile colorless solids. Sublimation is the common method of purification. Decaborane is highly flammable, and burns with a bright green flame like other boron hydrides. It is not sensitive to moist air, although it hydrolyzes in boiling water, releasing hydrogen and giving a solution of boric acid. It is soluble in cold water as well as a variety of non-polar and moderately polar solvents.[3]
In decaborane, the B10 framework resembles an incomplete octadecahedron. Each boron atom has one "radial" hydride, and four boron atoms near the open part of the cluster feature extra bridging hydrides. In the language of cluster chemistry, the structure is classified as "nido".
Synthesis and reactions
[edit]It is commonly synthesized via the pyrolysis of smaller boron hydride clusters. For example, pyrolysis of B2H6 or B5H9 gives decaborane, with loss of H2.[4] On a laboratory scale, sodium borohydride is treated with boron trifluoride to give NaB11H14, which is acidified to release borane and hydrogen gas.[3]
It reacts with Lewis bases (L) such as CH3CN and Et2S, to form adducts:[5][6]
- B10H14 + 2 L → B10H12L2 + H2
These species, which are classified as "arachno" clusters, in turn react with acetylene to give the "closo" ortho-carborane:
- B10H12 · 2 L + C2H2 → C2B10H12 + 2 L + H2
Decaborane(14) is a weak Brønsted acid. Monodeprotonation generates the anion [B10H13]−, with again a nido structure.
In the Brellochs reaction, decaborane is converted to arachno-CB9H−14:
- B10H14 + CH2O + 2 OH− + H2O → CB9H−14 + B(OH)−4 + H2
Possible applications
[edit]Decaborane has no significant commercial applications, although the compound has often been investigated. It and its derivatives were investigated as an additive to special high-performance rocket fuels. Its derivates were investigated as well, e.g. ethyl decaborane.[citation needed]
Decaborane is an effective reagent for the reductive amination of ketones and aldehydes.[7]
Decaborane has been assessed for low energy ion implantation of boron in the manufacture of semiconductors. It has also been considered for plasma-assisted chemical vapor deposition for the manufacture of boron-containing thin films. In fusion research, the neutron-absorbing nature of boron has led to the use of these thin boron-rich films to "boronize" the walls of the tokamak vacuum vessel to reduce recycling of particles and impurities into the plasma and improve overall performance.[8]
Safety
[edit]Decaborane, like pentaborane, is a powerful toxin affecting the central nervous system, although decaborane is less toxic than pentaborane. It can be absorbed through skin.
Purification by sublimation require a dynamic vacuum to remove evolved gases. Crude samples explode near 100 °C.[6]
It forms an explosive mixture with carbon tetrachloride, which caused an often-mentioned explosion in a manufacturing facility.[9]
In crystalline form, it reacts violently with red and white fuming nitric acid which has a use as rocket fuel oxidizer, producing an extremely powerful detonation.[10]
References
[edit]- ^ a b c d e f g h NIOSH Pocket Guide to Chemical Hazards. "#0175". National Institute for Occupational Safety and Health (NIOSH).
- ^ "Decaborane". Immediately Dangerous to Life or Health Concentrations. National Institute for Occupational Safety and Health.
- ^ a b Gary B. Dunks, Kathy Palmer-Ordonez, Eddie Hedaya "Decaborane(14)" Inorg. Synth. 1983, vol. 22, pp. 202–207. doi:10.1002/9780470132531.ch46
- ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
- ^ Charles R. Kutal; David A. Owen; Lee J. Todd (1968). "closo -1,2-Dicarbadodecaborane(12): [ 1,2-Dicarbaclovododecaborane(12 )]". Inorganic Syntheses. Vol. 11. pp. 19–24. doi:10.1002/9780470132425.ch5. ISBN 978-0-470-13170-1.
- ^ a b M. Frederick Hawthorne; Timothy D. Andrews; Philip M. Garrett; Fred P. Olsen; Marten Reintjes; Fred N. Tebbe; Les F. Warren; Patrick A. Wegner; Donald C. Young (1967). "Icosahedral Carboranes and Intermediates Leading to the Preparation of Carbametallic Boron Hydride Derivatives". Inorganic Syntheses. Vol. 10. pp. 91–118. doi:10.1002/9780470132418.ch17. ISBN 978-0-470-13241-8.
- ^ Jong Woo Bae; Seung Hwan Lee; Young Jin Cho; Cheol Min Yoon (2000). "A reductive amination of carbonyls with amines using decaborane in methanol". J. Chem. Soc., Perkin Trans. 1 (2): 145–146. doi:10.1039/A909506C.
- ^ Nakano, T.; Higashijima, S.; Kubo, H.; Yagyu, J.; Arai, T.; Asakura, N.; Itami, K. "Boronization effects using deuterated-decaborane (B10D14) in JT-60U". 15th PSI Gifu, P1-05. Sokendai, Japan: National Institute for Fusion Science. Archived from the original on 2004-05-30.
- ^ "Condensed version of the 79th Faculty Research Lecture Presented by Professor M. Frederick Hawthorne". UCLA.
- ^ "The Most DESTRUCTIVE Chemical Reaction from two NON-explosive components". YouTube. 21 December 2023.
YouTube video name: 'The Most DESTRUCTIVE Chemical Reaction from two NON-explosive components'
Further reading
[edit]- "Decaborane(14)". WebBook. NIST.
- "Boron and Compounds". National Pollutant Inventory. Australian Government.
- "Decaborane". Organic Chemistry Portal.
- "Boron compounds: decaborane (14)". WebElements.
- "NIOSH Pocket Guide to Chemical Hazards - Decaborane". Centers for Disease Control and Prevention.