Properties of Isocyanides

Isocyanides are colourless, highly unpleasant-smelling, volatile liquids -- considerably MORE poisonous than the corresponding cyanides, so much so that even a faint carbylamine-like odour during a synthesis is treated as a hazard warning in the laboratory. They are only slightly soluble in water but dissolve readily in organic solvents. Isocyanides are relatively LESS polar than the corresponding alkyl cyanides (the divalent, lone-pair-bearing isocyanide carbon distributes charge differently from the cyanide's C#N triple bond), so their melting and boiling points run lower than the analogous cyanide's -- the same polari …