The hyperconjugative stabilities of tert-butyl cation and 2-... | Chemistry | SolveeIt

Question

The hyperconjugative stabilities of tert-butyl cation and 2-butene, respectively, are due to

$\sigma \rightarrow p \, (empty) \, and \, \sigma \, \rightarrow \pi ^*$ electron delocalisations

$\sigma \rightarrow \sigma^* \, and \, \sigma \rightarrow \pi$ electron delocalisations

$\sigma \rightarrow \pi(filled) \, and \, \sigma \rightarrow \pi$ electron delocalisations

$\pi (filled) \rightarrow \sigma ^* \, and \, \sigma \rightarrow \pi ^*$ electrons delocalisations

Answer

$\sigma \rightarrow p \, (empty) \, and \, \sigma \, \rightarrow \pi ^*$ electron delocalisations

Explanation

Solution

PLAN Spreading out charge by the overlap of an empty p-orbital with
an adjacent $\sigma -$ t-bond is called hyperconjugation. This overlap
(the hyperconjugation) delocalises the positive charge on the
carbocation, spreading it over a larger volume, and this
stabilises the carbocation.
tertiary butyl carbocation has one vacant p-orbital, hence, it is
stabilised by $\sigma - p$ (empty) hyperconjugation.
In 2-butene, stabilisation is due to hyperconjugation between
$\sigma - \pi ^*$ electron delocalisation.

Chemistry Question on Organic Chemistry- Some Basic Principles and Techniques

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