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).[contradictory] It is a derived from acetylene by deprotonation using a sodium base, typically sodium amide.
HC≡CH + NaNH2 → NaC≡CH + NH3This compound, a white solid, has been characterized by neutron diffraction, which revealed an Na-C bond and a C≡C bond of 127 pm, which is longer than the C≡C bond length in acetylene itself (120.4 pm).
Monosodium acetylide can be used as a strong nucleophile in organic synthesis. However, it has largely been displaced in this application by monolithium acetylide, which can be prepared more easily.
Monosodium acetylide hydrolizes in contact with water, producing sodium hydroxide and acetylene.
NaC≡CH + H2O → HC≡CH + NaOHMonosodium acetylide is used in the Nef synthesis.
References
K. N. Campbell, B. K. Campbell (1950). "n-Butylacetylene". Organic Syntheses. 30: 15. doi:10.15227/orgsyn.030.0015. /wiki/Doi_(identifier) ↩
Atoji, Masao (1972). "Neutron Structure Determination of Monosodium Acetylide, NaC2H, at 293 and 5K". The Journal of Chemical Physics. 56 (10): 4947–4951. Bibcode:1972JChPh..56.4947A. doi:10.1063/1.1676972. /wiki/Bibcode_(identifier) ↩
K. N. Campbell, B. K. Campbell (1950). "n-Butylacetylene". Organic Syntheses. 30: 15. doi:10.15227/orgsyn.030.0015. /wiki/Doi_(identifier) ↩
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. /wiki/Doi_(identifier) ↩