Tuesday, July 28, 2009

I am supposed to locate all carbon-carbon double bonds in my assigned molecule for a project. Benzene is the..

I am supposed to locate all carbon-carbon double bonds (c=c) in my assigned molecule for a project. The only ones that I see in my molecule are located in benzene, but I didn't think that the double bonds shown in benzene were actually double bonds. I am not sure if I should mark them as actual carbon carbon double bonds or not...and I have no way of contacting my prof.


If you can understand this...what would you do in my situation? Would you state that the bonds in benzene are not actually double bonds, or would you mark them as double bonds?

I am supposed to locate all carbon-carbon double bonds in my assigned molecule for a project. Benzene is the..
benzene is an aromatic compound. For a compound to be aromatic it must have every other c-c bond be double bonds. So yes there are 3 double bonds in the ring. It is true though that the actual structure of benzene is a resonance form and the double bonds are shared between all of the carbons but for purposes of writing the structure, yes there are 3 double bonds.
Reply:because each bond between the 2 carbon atoms is neither single nor double but is intermediate in character namely a hybrid. Each bond is equivalent to the other and has bond order of 1 1/2. Remember that circle you write with benzene emphasizes that the bonds are equivalent and the electrons are delocalized. This is what I would say!
Reply:Kekule proposed that benzene contained 3 double bonds but that their position was not fixed and that an equilibrium exists between the two structures. Actually, neither structure exists; only one structure exists which is a hybrid of the two.





The sp2 hybridized caron atoms have a free p orbital, with equal overlapping with all other p orbitals forming a doughnut shaped pi electron cloud above and below the 6 carbon ring.





I would argue that the ring contains no double bonds in the normal meaning of the word.


No comments:

Post a Comment