Ethanethiol
 |
|
 |
|
| Names | |
|---|---|
| IUPAC name
Ethanethiol
|
|
| Other names
Ethyl mercaptan, Mercaptoethane, Ethyl sulfhydrate
|
|
| Identifiers | |
75-08-1  |
|
| ChemSpider | 6103 |
| Jmol 3D model | Interactive image |
| PubChem | 6343 |
| RTECS number | KI9625000 |
| UNII | M439R54A1D |
| UN number | 2363 |
|
|
|
|
| Properties | |
| C2H6S | |
| Molar mass | 62.13404 g·mol−1 |
| Appearance | Colorless liquid[3] |
| Odor | Rotten cabbage, flatulence, skunk-like[3] |
| Density | 0.8617 g·cm−3 |
| Melting point | −148 °C (−234 °F; 125 K) |
| Boiling point | 35 °C (95 °F; 308 K) |
| 0.7% (20°C)[3] | |
| Vapor pressure | 442 mmHg (20°C)[3] |
| Acidity (pKa) | 10.6 |
| Vapor pressure | {{{value}}} |
| Related compounds | |
|
Related compounds
|
Methanethiol Butanethiol Ethanol thiophenol |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
|
 verify (what is  ?) |
|
| Infobox references | |
Ethanethiol, commonly known as ethyl mercaptan, is a colorless gas or clear liquid with a distinct odor. It is an organosulfur compound with the formula CH3CH2SH. Abbreviated EtSH, it consists of an ethyl group (Et), CH3CH2, attached to a thiol group, SH. Its structure parallels that of ethanol, but with S instead of O. The odor of EtSH is infamous. Ethanethiol is more volatile than ethanol due to a diminished ability to engage in hydrogen bonding. Ethanethiol is toxic. It occurs naturally as a minor component of petroleum, and may be added to otherwise odorless gaseous products such as liquefied petroleum gas (LPG) to help warn of gas leaks. At these concentrations, ethanethiol is not harmful.
Preparation
Ethanethiol is prepared by the reaction of ethylene with hydrogen sulfide over a catalyst. The various producers utilize different catalysts in this process. It has also been prepared commercially by the reaction of ethanol with hydrogen sulfide gas over an acidic solid catalyst, such as alumina.[4]
Ethanethiol was originally reported by Zeise in 1834.[5] Zeise treated calcium ethyl sulfate with a suspension of barium sulfide saturated with hydrogen sulfide. He is credited with naming the C2H5S- group as mercaptum.
Ethanethiol can also be prepared by a halide displacement reaction, where ethyl halide is reacted with aqueous sodium bisulfide. This conversion was demonstrated as early as 1840 by Henri Victor Regnault.[6]
Odor
Ethanethiol has a strongly disagreeable odor that humans can detect in minute concentrations. The threshold for human detection is as low as one part in 2.8 billion parts of air.[citation needed] Its odor resembles that of leeks, onions, durian or cooked cabbage, but is quite distinct. Ethanethiol is intentionally added to butane and propane (see: LPG) to impart an easily noticed smell to these normally odorless fuels that pose the threat of fire, explosion, and asphyxiation.
Reactions
<templatestyles src="Module:Hatnote/styles.css"></templatestyles>
Ethanethiol is a valued reagent in organic synthesis. In the presence of sodium hydroxide, it gives the powerful nucleophile SEt−. The salt can be generated quantitatively by reaction with sodium hydride.[7]
Ethanethiol can be oxidized to ethyl sulfonic acid, using bleach and related strong aqueous oxidants. Weaker oxidants, such as ferric oxide give the disulfide, diethyl disulfide:
- 2 EtSH + H2O2 → EtS-SEt + 2 H2O
Like other thiols, it behaves comparably to hydrogen sulfide. For example, it binds, concomitant with deprotonation to "soft" transition metal cations, such as Hg2+, Cu+, and Ni2+ to give polymeric thiolato complexes, Hg(SEt)2, CuSEt, and Ni(SEt)2, respectively.
Uses
In the underground mining industry, ethanethiol or ethyl mercaptan is referred to as "stench gas".[8] The gas is released into underground mine ventilation systems as an early warning system to alert mine workers during an emergency.[9] In Ontario, mining legislation dictates that "The alarm system in an underground mine shall, consist of the introduction into all workplaces of sufficient quantities of ethyl mercaptan gas or similar gas to be readily detectable by all workers".[10]
See also
References
- ↑ Merck Index, 12th edition, 3771
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 3.3 Cite error: Invalid
<ref>tag; no text was provided for refs namedPGCH - ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.; Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
Lua error in package.lua at line 80: module 'strict' not found.
