hyperconjugation  animation

In organic chemistry, hyperconjugation is the interaction of 

the electrons in a sigma bond (usually C–H or C–C) with an 

adjacent empty (or partially filled) non-bonding p-

orbital, antibonding π orbital, or filled π orbital, to give an 

extended molecular orbital that increases the stability of the 

system. Only electrons in bonds that are β to the positively 

charged carbon can stabilize a carbocation by 

hyperconjugation.