Carbylamines

Carbylamines, also known as isocyanides or isonitriles, are a class of organic compounds with the general formula R-N≡C, where R is an alkyl or aryl group. They are isomers of nitriles (R-C≡N), meaning they have the same molecular formula but a different arrangement of atoms. The carbon atom in the isocyanide functional group carries a formal positive charge, while the nitrogen atom carries a formal negative charge, leading to a zwitterionic character. This electronic structure influences their reactivity.

Carbylamines are characterized by a distinct and often unpleasant odor, which is a key property used for their identification. They are typically prepared through the dehydration of formamides or by the reaction of primary amines with chloroform in the presence of a strong base (the Hofmann isocyanide synthesis).

The reactivity of carbylamines is diverse. They can undergo reactions such as hydrolysis to form amines and formic acid, addition reactions across the carbon-nitrogen triple bond, and cycloaddition reactions. Their ability to act as ligands in coordination chemistry is also notable, forming stable complexes with various transition metals. Due to their strong and unpleasant smell, carbylamines are often synthesized and used in situ or handled with extreme caution in well-ventilated areas.