Q8P - Organic Chemistry (Mcmurry)

Question

Draw a resonance structure of the acetonitrile anion, 

 and account for the acidity of nitriles. 

Step-by-Step Solution

Answer

The acidity of nitriles occurs due to the removal of a proton and its stable conjugate base stabilised by resonance.

 

Step 1: Resonance structure of acetonitrile anion

The resonance structure of acetonitrile anion as

Step 2: Explanation of the resonance structure of acetonitrile anion

Acetonitrile has the formula 

The Hydrogens in the methyl groups are acidic in nature as they are attached to the electron withdrawing nitrile group. Now, removal of a proton forms an anion 

 

This anion is stabilized by resonance.

 

Step 3: Acidity of nitriles

The acidity of nitriles occurs due to the removal of a proton which is also stabilized by resonance.

 

 

Step 4: Conclusion

Hence, you can draw the resonance structure of acetonitrile anion as