Question

expain why haloalkanes give KCN (alc) nd isocyanide with AgCN(alc)

Answer 1

So, CN- gives alkyl cyanide by forming a C-C bond due to more preferred soft-soft interaction. AgCN, on the other hand is a covalent compound and it does not dissociate easily to give CN-. In this case, the attacking centre will be N-atom, as it is softer as compared to the N-atom in KCN.

#CAN THIS BE A REACTION??????????

@SNEHASINGH

Answer 2

Answer:

KCN is an ionic compound so it provides CN⁻ ions in solution

         KCN ----> K⁺ ₊ CN⁻

CN⁻ is an ambident nucleophile in which both C and N atoms are free to donate electron pair and can attack at nucleophilic center. But C-C bond is stronger than C-N bond therefore the attack of CN⁻ nucleophile is mostly through C atom and hence alkyl cyanides are obtained as main product on treating alkyl halide with alcoholic KCN solution.

On the other hand AgCN is covalent in nature .

       AgCN----> Ag-CΞN

So only N stom can donate its lone pair of electrons. Therefore AgCN attacks at nucleophilic center through N atom and hence alkyl isocyanides are obtained as main product on treating alkyl halide with alcoholic AgCN solution.

            R-X + KCN (alc) ----> R-CN + KX

            R-X + AgCN (alc) ----> R-NC +AgX

Explanation: