Tribromoethanol
Chemical compound
From Wikipedia, the free encyclopedia
2,2,2-Tribromoethanol, often called just tribromoethanol, is a chemical compound with formula Br3C−CH2OH. Its molecule can be described as that of ethanol, with the three hydrogen atoms in position 2 (on the methyl group) replaced by bromine. It is a white crystalline solid, soluble in water and other solvents, that absorbs strongly in the UV below 290 nm.[2]
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| Trade names | Avertin |
| Other names | Tribromoethyl alcohol |
| Identifiers | |
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| ECHA InfoCard | 100.000.822 |
| Chemical and physical data | |
| Formula | C2H3Br3O |
| Molar mass | 282.757 g·mol−1 |
| 3D model (JSmol) | |
| Melting point | 73–79 °C (163–174 °F) [1][2] |
| Boiling point | 199 °C (390 °F) at 1atm [1] |
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Tribromoethanol is used in medicine and biology as an anesthetic, and has been available commercially for that purpose by the trade name Avertin. It was formerly used on humans[3] and is still often used on laboratory animals,[4] and to capture wild birds.[5] It is also used in plastics industry as a polymerization initiator.[6][7]
Uses
Animal anesthetic
Tribromoethanol is often used to anesthetize laboratory animals, particularly rodents, before surgery.[4] As a solution in tert-amyl alcohol, it has the brand name Avertin.[8] The tert-amyl alcohol acts as a weak hypnotic, in addition to improving the solubility of the tribromoethanol. Administered intravenously, tribromoethanol (Avertin) causes rapid and deep anesthesia followed by rapid and full postoperative recovery in small mammals.[9] Recently its safety for this purpose has been questioned.[10]
Wildlife capture
Tribromoethanol has also been long used as spiked grain bait to capture wild turkeys for research and wildlife management purposes.[5] However, the birds learn to avoid it, for over a year, after a single exposure, and will drive other flock members away from the bait when they detect it.[11]
Human anesthetic
In the first half of the 20th century, Avertin was also used in humans as a general anesthetic or basal narcotic to induce unconsciousness prior to the administration of other anesthetic agents. It was administered rectally as a retention enema or by intravenous injection. Its rectal use was particularly favored for pediatrics, head or neck surgery, or in mentally unstable or anxious patients.[3] Electrophysiology studies showed that tribromoethanol acts as a positive allosteric modulator of the inhibitory GABAA and glycine receptors, a mechanism similar to that seen with the related compound 2,2,2-trichloroethanol.[12] Bromal hydrate (2,2,2-tribromoethanol-1,1-diol), a compound also recognized to produce general anesthesia in animals, is metabolized to tribromoethanol.[13]
Polymerization initiator
Tribromoethanol can be used as a functional polymerization initiator for the introduction of α-hydroxyl groups in poly(methyl methacrylate) (PMMA) and poly(n-butyl acrylate) (PBAK).[6][14][7]
Chemistry
Photolysis
Tribromoethanol should be kept refrigerated and in the dark, to prevent decomposition by light into hydrobromic acid and possibly 2,2-dibromoacetaldehyde or glycolic acid.[15][2]