Answers are grounded in this paper and cite their sources.
The normal boiling point for cyanogen is −22 °C; for its next homologue, malononitrile, it is 219 °C. The difference of 241 °C is apparently the highest one encountered for the addition of a single methylene group. Problems connected with boiling points and a rationalization for this observation are discussed in the context of intermolecular forces for liquids. A quantitative structure−property relationship (QSPR) study of the normal boiling points for monohaloalkanes and for the corresponding nitriles is reported. The behavior of the nitrile group as a pseudohalogen is also discussed. Normal boiling points of compounds having a cyano group bonded to an electron-attracting substituent situate the CN group close to being a pseudohalogen, but when the CN group is bonded to electron-donor substituents, the situation changes.
No takes yet. Share an insight, caveat, or question.
Balaban et al. (1999) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: