| Benzeneselenol | |
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benzeneselenol |
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Other names
Selenaphenol, |
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| Identifiers | |
| CAS number | 645-96-5 |
| PubChem | 69530 |
| ChemSpider | 62734 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C6H6Se |
| Molar mass | 157.07 g/mol |
| Appearance | colourless liquid |
| Density | 1.479 g/cm3 |
| Boiling point |
71-72 °C (18 mm Hg) |
| Solubility in water | slightly |
| Solubility in other solvents | most organic solvents |
| Refractive index (nD) | 1.616 |
| Structure | |
| Dipole moment | 1.1 D |
| Hazards | |
| R-phrases | 23/25-33-50/53 |
| S-phrases | 20/21-28-45-60-61 |
| Main hazards | toxic |
| Related compounds | |
| Related compounds | C6H5SH, H2Se, diphenyl diselenide |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Benzeneselenol is the chemical compound with the formula C6H5SeH, often abbreviated PhSeH. This intensely malodorous liquid is a useful reagent in organic synthesis.
PhSeH is prepared via the reaction of phenylmagnesium bromide and selenium:[1]
More so than thiophenol, benzeneselenol is easily oxidized by air to give diphenyl diselenide. An idealized equation for this reaction is:
The presence of the diselenide is signaled by a yellow coloration in most samples of PhSeH. The diselenide can be converted back to the selenol by reduction followed by acidification of the resulting PhSe−.
PhSeH is approximately seven times more acidic than the related thiophenol. Both compounds dissolve in water upon the addition of base.
PhSeH is renowned in organic synthesis as the precursor to its conjugate base PhSe−, a potent nucleophile.[2]
Benzeneselenol was first prepared by the reaction of benzene with SeCl4 in the presence of AlCl3.[3]