00:01
This question asks us which of the compounds shown are aromatic.
00:07
So remember there are four rules to be aromatic.
00:10
You have to be cyclic, planer.
00:15
You have to have open p orbitals for the electrons to move around in, and you have to follow huckle's rule of electrons.
00:24
You have to have four n plus two electrons.
00:27
So starting with part a, we are cyclic and planar, but we don't follow rule number three, which is the open p orbitals, and we know this because these two carbons are both sp3.
00:38
So this is not aromatic because of that.
00:42
Those electrons cannot move all the way around the ring.
00:44
For part b, here again, we have an sp3 carbon, and actually both part a and part b have four electrons, which does not follow huckle's rule...