Science Buddies: "Ask an Expert"

Given an atom in a molecule, how do I know whether it is aliphatic/aromatic? I know that stuff like benzene becomes more stable due to delocalized pi-bonds and is thus called 'aromatic'.

But from a molecular graph perspective, given a bunch of atoms connected together how do I know whether a node is aliphatic/aromatic?

Thanks!

ericjang,

Given your earlier posts that I've replied to, you seem like a fairly sophisicated guy, so I wonder just how much detail you're looking for here. Maybe someone else on Science Buddies will supply more. Better yet, you should consult some textbooks on organic chemistry since aromatic compounds are very important in organic chemistry.

About all I know is that structures are referred to as aromatic when they contain shared π electrons. A summary of the characteristics of aromatic structures is given in http://en.wikipedia.org/wiki/Aromaticity. Even an introductory textbook on organic chemistry will go into more details.

Good luck, WW