Eduprobe
Question:
The hyperconjugative stabilities tert-butyl cation and 2-butene, respectively, are due to:
σ→p(empty) and σ→π* electron delocalisations
p(filled)→σ* and σ→π* electron delocalisations
σ→σ* and σ→π electron delocalisations
σ→p(filled) and σ→π electron delocalisations
Solution:
Hyperconjugation is due to the interaction of the electrons in σ bond (C-H or C-C) with adjacent empty or partly filled non-bonding p-orbital, antibonding π orbital or filled π orbital. This result in extended molecular orbital and increases the stability of the system. In case of tert-butyl cation, the hyperconjugation is due to the interaction of the electrons in the σ bond with adjacent empty p-orbital. H3C−CH3|C+|CH3 σ−p(empty) In case of 2-butene, the hyperconjugation is due to the interaction of σ orbital with antibonding π orbital.