Hyperconjugation: Is it a Co-ordinate Bond?

[Karan Punjabi]

Guys, a certain chemical phenomenon known as hyperconjugation in which carbonium ion which is tertiary or secondary or primary in nature then the pi bond formed for stabilizing effect can be defined as a co ordinate bond or not?

 

[Karan Punjabi]

Please help me

 

[TeethWhitener]

I'm not sure I'd refer to hyperconjugation as a coordinate bond, but it probably all boils down to semantics. You're onto something, though: the ideas of hyperconjugation and coordinate bonding are similar. In both cases you have systems where electrons from a filled orbital are donated into an empty orbital. Normally, what I see referred to as coordinate bonds (like between NH₃ and BH₃) involve the donation of a full electron pair, whereas in hyperconjugation, only a fraction of the pi bond electron density gets donated into the adjacent sigma antibond. It's more a difference of degree than a difference of kind.

 

[Steven Hanna]

Guys, a certain chemical phenomenon known as hyperconjugation in which carbonium ion which is tertiary or secondary or primary in nature then the pi bond formed for stabilizing effect can be defined as a co ordinate bond or not?

I agree with TeethWhitener. I don't think a hyperconjugative interaction qualifies as a bond in the first place. But you likely learned in gen chem that a coordinate (or dative) covalent bond is a bond that was formed from a 2 e- interaction between a lewis acid and a lewis base. However, if you just look at a molecule by itself, e.g. CCl4, you can't say whether the bonds are dative or not. This molecule could be made from radicals or ions. Cl- + Cl3C+ --> CCl4 but Cl. + CCl3. -->