Monosodium acetylide
Chemical compound
From Wikipedia, the free encyclopedia
Monosodium acetylide, also known as sodium hydrogen acetylide, is an organosodium compound with the formula NaC≡CH. It is a sodium salt of acetylene, consisting of sodium cations (Na+) and hydrogen acetylide anions (−C≡CH). It is derived from acetylene by deprotonation using a sodium base, typically sodium amide.[2]
- HC≡CH + NaNH2 → NaC≡CH + NH3
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| Names | |
|---|---|
| IUPAC name
Ethynylsodium | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.012.645 |
| EC Number |
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| 174471 | |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| C2HNa | |
| Molar mass | 48.020 g·mol−1 |
| Appearance | white solid |
| Density | 1.352 g/cm3 |
| hydrolyzes | |
| Hazards | |
| GHS labelling:[1] | |
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| Danger | |
| H261, H314 | |
| P231+P232, P260, P264, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P370+P378, P402+P404, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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This compound, a white solid, has been characterized by neutron diffraction, which revealed a C≡C bond of 127 pm, which is longer than the C≡C bond length in acetylene itself (120.4 pm). The negative formal charge is essentially localized on one of the carbon atoms.[3] Millimeter spectroscopy yielded Na−C and C≡C bond lengths of 222.1 pm and 121.7 pm, respectively. The C−H bond length is assumed to be 106 pm.[4]
Monosodium acetylide can be used as a strong nucleophile in organic synthesis.[2] However, it has largely been displaced in this application by monolithium acetylide, which can be prepared more easily.[5]
Monosodium acetylide hydrolizes in contact with water, producing sodium hydroxide and acetylene.
- NaC≡CH + H2O → HC≡CH + NaOH
Monosodium acetylide is used in the Nef synthesis.
Monosodium acetylide is theorized to exist in the outer envelopes of carbon stars such as IRC +10216, where it could be formed by the reaction between sodium or sodium cations and ethynyl radicals or acetylene cations (HCCH+), the latter two produced by photodissociation.[6]