Can someone explain the best way that they approach aromaticity problems? Any quick shortcuts?
Thank you!
Thank you!
Huckel's Rule
- Thread starter picassoo
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I never really used Huckel's rule to determine aromaticity. Instead, I used somewhat of a derivative of it. So here's my system for determining aromaticity:
1) Make sure there is an uninterrupted pi-cycle (ie. no sp3 atoms intervening within sp2/sp atoms in a ring); if there isn't an uninterrupted pi-cycle then it is non-aromatic
2) Count the number of double bonds/lone pairs within the ring cycle and if you get an odd number it is aromatic; even number = antiaromatic. For example, the molecule below would be considered aromatic. There is a total of 4 double bonds + 1 lonepair = 5 (odd number; therefore, aromatic!)
A caveat to this is that you have to MAKE SURE that if you're including a lone pair in your "count", that lone pair has to participate in making the ring aromatic (ie. it must be directly beside an sp2 or sp carbon so that can "participate" in the aromatic cycle via resonance)
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