See Ethyne

CaC2 + 2H2O C2H2 + Ca(OH)2 The structure of calcium dicarbide is interesting because the carbon is present as carbide ions See ethyne. 

HOCH2CH2CH2CH2OH. B.p. 228"C. Prepared ethyne plus methanal, hydrogenated to butanediol. Used in production of y-buty-rolactone and 2-pyrrolidone. Widely used in polyurethane products, butylenes See butenes. 

The C-C distance in CaC2 is close to that in ethyne (120.5 pm) and it has been suggested that the observed increase in the lanthanoid and actin-oid carbides results from a partial localization of the supernumerary electron in the antibonding orbital of the ethynide ion [C=C] (see p. 932). The effect is noticeably less in the sesquicarbides than in the dicarbides. The compounds EuC2 and YbC2 differ in their lattice parameters and hydrolysis behaviour from the other LnC2 and this may be related to the relative stability of Eu and Yb (p. 1237). 

The most significant changes associated with adsorption which have been observed to date were the displacements (45) of Raman fundamentals of ethyne on adsorption on zeolite 4A (see Table IX). Such changes constitute a useful monitor of adsorbate-adsorbent interaction for various adsorbents. The appearance of the Raman spectrum of ethyne on zeolites A suggests an... 

Scheme 3.2-39. The spirocarbaborane 55g is formed as one component (see Scheme 3.2-27) in the hydride bath starting from bis(diethylboryl)ethyne as the result of hydroboration and Et2BH-catalyzed condensations.

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