When haloalkanes react with alc. sodium cyanide gives alkyl cyanide but when reacted with alc. silver cyanide gives alkyl isocyanide. Why? with example and reactions
CN ion is an ambidient nucleophile i.e. those ions which possess two possible sites to attack at the electron-deficient centre.
Both carbon and Nitrogen can supply a pair of electrons during the nucleophilic attack.
Alcoholic NaCN or KCN liberate CN- ions freely as AgCN -----> Na+ + -CN (here C attacks first)
and form alkane nitriles as product.
However for alc. AgCN, the bond here is covalent bond. In this, C only has a polar negative charge which is less. Instead, N which has one lone pair...