Question #bcd01

1 Answer
Dec 19, 2017

One orbital per C-H bond


The p-orbital involved in the C-H bond is co-planar with the empty p-orbital in the methyl carbocation. This geometry means that hyperconjugation can occur, with the electrons in the #sigma#-bond stabilising the carbocation centre.

The stabilisation is energetically favourable, because it results in the electrons in the #sigma#-bond being in a lower energy level.

The C-C bond can rotate, so the carbocation can form stabilising interactions with multiple C-H bonds e.g. ethyl cation has 3 C-H bonds that can be involved in hyperconjugation.