Bromoform
| Bromoform | |
|---|---|
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 |
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| IUPAC name Tribromomethane[1] | |
| Other names
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| Identifiers | |
| Abbreviations |
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| CAS number | 75-25-2  |
| PubChem | 5558 |
| ChemSpider | 13838404 |
| UNII | TUT9J99IMU |
| EC number | 200-854-6 |
| UN number | 2515 |
| DrugBank | DB03054 |
| KEGG | C14707 |
| MeSH | bromoform |
| ChEBI | CHEBI:38682 |
| ChEMBL | CHEMBL345248 |
| RTECS number | PB5600000 |
| Beilstein Reference | 1731048 |
| Gmelin Reference | 49500 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | CHBr3 |
| Molar mass | 252.73 g mol−1 |
| Appearance | Colorless liquid |
| Density | 2.89 g mL−1 |
| Melting point | −4 to 16 °C; 25 to 61 °F; 269 to 289 K |
| Boiling point | 147 to 151 °C; 296 to 304 °F; 420 to 424 K |
| Solubility in water | 3.2 g L−1 (at 30 °C) |
| log P | 2.435 |
| Vapor pressure | 670 Pa (at 20.0 °C) |
| kH | 17 μmol Pa−1 kg−1 |
| Refractive index (nD) | 1.595 |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
6.1–12.7 kJ mol−1 |
| Std enthalpy of combustion ΔcH |
−549.1–−542.5 kJ mol−1 |
| Specific heat capacity, C | 130.5 J K−1 mol−1 |
| Hazards | |
| MSDS | External MSDS |
| GHS pictograms |   |
| GHS signal word | DANGER |
| GHS hazard statements | H302, H315, H319, H331, H411 |
| GHS precautionary statements | P261, P273, P305+351+338, P311 |
| EU Index | 602-007-00-X |
| EU classification |  T  N |
| R-phrases | R22, R23, R36/38, R51/53 |
| S-phrases | (S1/2), S45, S63 |
| NFPA 704 |
 0
3
0
|
| LD50 | 933.0 mg kg−1 (oral, rat) |
| Related compounds | |
| Related alkanes | |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Bromoform (CHBr3) is a brominated organic solvent, pale yellow liquid at room temperature, with a high refractive index, very high density, and sweet odor is similar to that of chloroform. It is a trihalomethane, and is one of the four haloforms, the others being fluoroform, chloroform, and iodoform. Bromoform can be prepared by the haloform reaction using acetone and sodium hypobromite, by the electrolysis of potassium bromide in ethanol, or by treating chloroform with aluminum bromide. Currently its main use is as a laboratory reagent.
Uses
Only small quantities of bromoform are currently produced industrially in the United States. In the past, it was used as a solvent, sedative and flame retardant, but now it is mainly used as a laboratory reagent, for example as an extraction solvent.
Bromoform's high density makes it useful for separation of minerals by buoyancy. When two samples are mixed with bromoform and then allowed to settle, the top layer will contain minerals lighter than bromoform, and the bottom layer will contains heavier minerals. Slightly less dense minerals can be separated in the same way by mixing the bromoform with a small amount of a less dense and fully miscible solvent.
Environment and Toxicology
Natural production of bromoform by phytoplankton and seaweeds in the ocean is thought to be its predominant source in the environment.[2] However, locally significant amounts of bromoform enter the environment formed as disinfection byproducts known as trihalomethanes when chlorine is added to drinking water to kill bacteria. It is somewhat soluble in water and readily evaporates into the air. Bromoform is the main trihalomethane produced in salt swimming pools with some public swimming pools found to contain up to 1.3 ppm (parts per million) bromoform.[3] Occupational skin exposure limits are set at 0.5 ppm.[4]
The substance may be hazardous to the environment, and special attention should be given to aquatic organisms. Its volatility and environmental persistence makes bromoform's release, either as liquid or vapor, strongly inadvisable.
Bromoform can be absorbed into the body by inhalation and through the skin. The substance is irritating to the respiratory tract, the eyes, and the skin, and may cause effects on the central nervous system and liver, resulting in impaired functions. It is soluble in about 800 parts water and is miscible with alcohol, benzene, chloroform, ether, petroleum ether, acetone, and oils. Its LD50 is 7.2 mmol/kg in mice, or 1.8g/kg. Bromoform is a confirmed animal carcinogen; (ACGIH 2004). Carcinogen category: 3B; (DFG 2004).
References
- Betterton E. A., Arnold R. G., Kuhler R. J., Santo G. A. (June 2005). "Reductive dehalogenation of bromoform in aqueous solution". Environ Health Perspect. (Brogan &) 103: 89–91(3). doi:10.2307/3432487. JSTOR 3432487. PMC 1519304. PMID 8565919. Retrieved 2007-07-03. PDF
- U.S. Department of Health and Human Services. Toxicological Profile for Bromoform and Dibromochloromethane . August 2005.
- ↑ "bromoform - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification. Retrieved 18 June 2012.
- ↑ Palmer C J and Reason C J (2009), Relationships of surface bromoform concentrations with mixed layer depth and salinity in the tropical oceans (2009), Global Biogeochemical Cycles, 23, GB2014.
- ↑ Beech AJ et al (1980) Nitrates, Chlorates and Trihalomethanes in Swimming Pool Water. Am J Public Health, 70(1), 79-82
- ↑ CDC - NIOSH Pocket Guide to Chemical Hazards
External links
- International Chemical Safety Card 0108
- NIOSH Pocket Guide to Chemical Hazards 0066
- Entry at chemicalland21.com
- Toxicological profile for bromoform and dibromochlormethane
- Toxicity summary
- IARC Summaries & Evaluations: Vol. 62 (1991), Vol. 71 (1999)
- ChemSub Online: Bromoform
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