I thought the extent of this topic was just to know if something is aromatic or not, but obviously I am wrong since I have been doing practice questions and they compare aromatic vs nonaromatic vs antiaromatic in reactivity. So what does it mean in regards to reacitivty.
Anti-aromatic compounds are very unstable. The electrons are NOT placed in bonding molecular orbitals.These compounds are DESTABILIZED by a closed loop of electrons.
Cyclobutadiene is so unstable that it is very very difficult to isolate !!!!
We have to trap it in a " molecular cage " or put so-called shackles on it at low temperatures to even isolate and study it. My professor called the molecule THE BEAST .
It is so highly reactive that it combines with itself !!!!
An aromatic compound is highly stable, and much less reactive. Without an Fe catalyst, benzene will not even react with chlorine or bromine !!!! Without a suitable Lewis acid like AlCl3, it will not react with methyl chloride. Aromatic compounds normally do not react with acids or bases. Aromatic compounds are very stable, because all the electrons are placed into bonding molecular orbitals.
For the DAT exam, practice on identifying if a compound is Aromatic !!!! You need to look for a Huckel number, planar molecule, delocalized pi electrons, and a cyclic structure.
I hope this helps.
Dr. Romano
