Carbocations in general are stabilized by hyperconjugative interactions where po
ID: 936105 • Letter: C
Question
Carbocations in general are stabilized by hyperconjugative interactions where possible. The standard picture of this stabilization is illustrated below left (structure 1), with the empty p orbital mixing with an aligned sp3 hybrid C-H bond. The vinyl carbocation presents a variant of this hyperconjugative interaction. Now, an sp2 hybrid is mixing with the empty p orbital. Hyperconjugative interaction 2 differs from the standard model 1 in two important aspects: (1) The hybrid orbital used by the carbon of the C-H bond is different (sp3 in 1 vs. sp2 in 2), and (2) the angle between the C-H bond and the p orbital is different (~ 109degree in 1 vs. ~ 120degree in 2 - Note: the real bond angles are probably a little less in both cases, but we will use the canonical angles for convenience). Are the changes expressed in 2 more or less stabilizing than the standard model values illustrated with 1?Explanation / Answer
Answer .a