acepentalene aromaticity perception #2895
Take a look at the following, which uses the SMILES from https://en.wikipedia.org/wiki/Acepentalene :
Why is there an aromatic "c" in the fused center of the 3 5-membered rings. It's connected by non-aromatic bonds to the rest of the system.
This broke some code of mine which expects that every aromatic atom must have at least two aromatic bonds. I thought that all aromatic atoms had to be in aromatic rings, and that all aromatic rings had to have aromatic bond.
I searched for "acepentalene" and "antiaromatic" in the issue tracker and the mailing list but found nothing relevant.
I brought this up on the mailing list. Peter Shenkin further commented:
There was no other response to the thread, so I'm posting here for when someone has time to look into it further.
Quick summary of the discussion on the list: