[h1234]

hi

I could not understand the full meaning of Induction and hyperconjugation?
Can anyone tell me in really simple words?

Kind regards

[Jorriss]

Induction is like polarity. A more electonegative atom pulls the electrons in a molecule toward it, through sigma bonds.

For example, trifluoroacetic acid. The fluorine groups have an inductive effect by yanking electron density towards themselves - through sigma bonds.


Hyperconjugation I'll leave to someone else who could explain it better. It has to do with conjugated orbitals but I can't explain it nicely and frankly, I don't feel comfortable with my own understanding enough to help.

[tamim83]

Hypercongugation is when electron density from a sigma bond stabilizes an adjacent empty or partially filled p orbital.  It accounts for the trend of increased stability with more substituted alkyl cations and radicals and a few more trends, including how alkyl groups donate electron density (via induction). 

It is similar to resonance (or pi delocalization), but isn't the same thing.  I can only speculate on the difference; pi delocalization takes place between atomic orbitals (usually p) and results in molecular orbitals that are spread out over several atoms.  In hyperconjugation, atomic orbitals are interacting with bonding molecular orbitals, the overlap is not very strong.  They both have similar stabilizing effects. 

Pictures work well to explain hyperconjugation so here are some links with pictures and some more info.  Hope this helps some. 

http://en.wikipedia.org/wiki/Hyperconjugation
http://www.chem.ucalgary.ca/courses/350/Carey/Useful/hyperconjugation.html