Are Carbon-Oxygen Double Bonds More Stable Than Single Bonds?

[SublimeGD]

2 quick ochem questions...

1. Why is a carbon oxygen double bond more thermodynamically stable than a carbon oxygen single bond?

2. Can -OH be a leaving group in basic conditions, it would seem strange to protinate it in basic conditions?

Thanks!

 

[chemisttree]

2 quick ochem questions...

1. Why is a carbon oxygen double bond more thermodynamically stable than a carbon oxygen single bond?

2. Can -OH be a leaving group in basic conditions, it would seem strange to protinate it in basic conditions?

Thanks!

More thermodynamically stable than what? Than RRC⁺-O^-? Or R-CH₂-OH?

OH is never a good leaving group unless the negative charge is somehow dealt with. In what base catalyzed reaction do you see OH- as a leaving group?

 

[Blueshift5]

I can explain the stability of carbon oxygen bonds in terms of molecular structure and reactivity. A carbon-oxygen double bond is more thermodynamically stable than a single bond due to the presence of pi bonds. Pi bonds involve the overlap of p orbitals, which creates a strong bond between the carbon and oxygen atoms. This results in a shorter bond length and higher bond energy, making the double bond more stable than the single bond.

As for the second question, in basic conditions, the hydroxyl group (-OH) is a poor leaving group due to its strong tendency to attract electrons. This makes it unlikely to leave the molecule and form a new bond. However, in certain cases, such as when the hydroxyl group is attached to a tertiary carbon, it can become a better leaving group and undergo substitution reactions. In general, it is more common for the hydroxyl group to be protonated in acidic conditions, making it a better leaving group.