Question

Resonance delocalization can also be used to rationalize the stability of cations (empty p-orbitals). Note that in the following series of molecules the order of stability is D<E<F.

12.Resonance delocalization can also be used to rationalize the stability of cations (empty p-orbitals) Note that in the following series of molecules the order of stability is D<E<F. H3C HaC HaC H3C C-CH2 C-O: C-N: H3C CH3 H3C CH CH LEAST STABLE CATION MOST STABLE CATION a) If the difference in stability was entirely due to the inductive effect (the polarization of bonds by electron withdrawing groups) what would be the expected order of stability of the above cations? [Hint: Draw all bond dipoles for the above molecules. Do any of the bond dipoles enhance the positive charge of the cation (a destabilizing effect)?] b) Explain carefully with drawings and words how resonance can account for the observed order of stability of the cations [Hint: Try drawing resonance structures for each of the examples options.].

          
a)  If the difference in stability was entirely due to the inductive effect (the polarization of bonds by electron withdrawing groups) what would be the expected order of stability of the above cations? [Hint: Draw all bond dipoles for the above molecules. Do any of the bond dipoles enhance the positive charge of the cation (a destabilizing effect)?]      

b) Explain carefully with drawings and words how resonance can account for the observed order of stability of the cations [Hint: Try drawing resonance structures for each of the examples options.].

Answer 1

New, o» CH CH Every ahm has a ー(pos,hve charge on oxygen (e lecho negah ve atem) Res man han oxy -Hence tu ase