Chemistry:Monosodium acetylide
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| Names | |
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| IUPAC name
Ethynylsodium
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Other names
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
| EC Number |
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| 174471 | |
PubChem CID
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| Properties | |
| C2HNa | |
| Molar mass | 48.020 g·mol−1 |
| Appearance | white solid |
| Density | 1.352 g/cm3 |
| hydrolyzes | |
| Hazards | |
| GHS pictograms |  
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| GHS Signal word | Danger |
| H261, H314 | |
| P231+232, P260, P264, P280, P301+330+331, P302+361+354Script error: No such module "Preview warning".Category:GHS errors, P304+340, P305+354+338Script error: No such module "Preview warning".Category:GHS errors, P316Script error: No such module "Preview warning".Category:GHS errors, P321, P363, P370+378, P402+404, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
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 + NaNH
2 → NaC≡CH + NH
3
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 + H
2O → 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]
References
- ↑ "Sodium acetylide" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/2733336#section=Safety-and-Hazards.
- ↑ 2.0 2.1 K. N. Campbell, B. K. Campbell (1950). "n-Butylacetylene". Organic Syntheses 30: 15. doi:10.15227/orgsyn.030.0015.
- ↑ Atoji, Masao (1972). "Neutron Structure Determination of Monosodium Acetylide, NaC2H, at 293 and 5K". The Journal of Chemical Physics 56 (10): 4947–4951. doi:10.1063/1.1676972. Bibcode: 1972JChPh..56.4947A.
- ↑ Grotjahn, Douglas B.; Apponi, Aldo J.; Brewster, Matthew A.; Xin, Ju; Ziurys, Lucy M. (1998-10-16). "Structures of Solvent-Free, Monomeric LiCCH, NaCCH, and KCCH". Angewandte Chemie International Edition 37 (19): 2678–2681. doi:10.1002/(SICI)1521-3773(19981016)37:19<2678::AID-ANIE2678>3.0.CO;2-6. ISSN 1433-7851. https://onlinelibrary.wiley.com/doi/10.1002/(SICI)1521-3773(19981016)37:193.0.CO;2-6. Retrieved 2026-05-06.
- ↑ M. M. Midland; J. I. McLoughlin; R. T. Werley Jr. (1990). "Preparation and Use of Lithium Acetylide: 1-Methyl-2-Ethynyl-endo-3,3-Dimethyl-2-Norbornanol". Organic Syntheses 68: 14. doi:10.15227/orgsyn.068.0014.
- ↑ Li, B. Z.; Ziurys, L. M. (1997-06-20). "Laboratory Detection and Submillimeter Spectrum of NaCCH (x̃ 1Σ)". The Astrophysical Journal 482 (2): L215–L217. doi:10.1086/310707. https://iopscience.iop.org/article/10.1086/310707. Retrieved 2026-05-06.
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