What is the function of an aromatic ring?

What is the role of chlorinated aromatic ring in the function of 2,4-D?

• how 2,4-D act as as a herbicide? is the role of chlorinated aromatic ring important for 2,4-D acting? can a chemical compound with similar chlorinated ring act similar to 2,4-D?

• Answer:

  The molecule is similar in shape and probably polarity to auxins or plant hormones that make it grow. There aren't any chlorine molecules on the actual hormone so the chlorine apparently only makes the chemical fit the receptor protein better on cell membrane. Other similar chemicals could probably be used. It is probably trial and error with similar easy to make chemicals first since the point is to make money. Someone could examine the protein carefully and likely figure out a better configuration to make a more effective pesticide if they want to. It would likely be more expensive to synthesize. This seemed like the most useful link. http://en.wikipedia.org/wiki/Auxin