February 24, 2011

Aromaticity

Dear Granny,
            In Organic Chemistry II, we’ve been discussing aromaticity. Aromatic compounds are a ring of carbon atoms with alternating single and double bonds. They are defined as compounds that are cyclic, planar, completely conjugated, and obey Huckel’s Rule. They received the name “aromatic” because of their distinct characteristic odors. Cyclic compounds are compounds in a ring; for example: Benzene. Planar means that the compound is flat like a sheet of paper. Conjugation is the overlap of p-orbitals in the molecule. An orbital is the cloud around the molecule that stores the electrons. P-orbitals are a dumbbell shape around the element that is attached to a double bond. Huckel’s Rule is (4n + 2), which determines the number of π electrons in the compound. Each pi electron gives 2 electrons. The easiest way I remember whether it obeys Huckel’s role, without calculating, is by remembering that the number of π electrons begins with 2 and increases by 4. So if it contains 2, 6, 10, 14, 18, 22, 26, etc.  π electrons, it is aromatic. Compounds that are cyclic, planar, and conjugated, but do not obey Huckel’s Rule, their π electrons = 4n, are considered antiaromatic. If the compound disobeys at least two of the rules to be aromatic, it is considered nonaromatic. I hope you learned something new.

Love,
 Jesslyn

1 comment:

  1. This blog was great. You did a great job of explaining the many parts pertaining to chemistry. If I had not known what any of those terms meant, I would now. I feel like you explained aromaticity perfectly, there was no room for misinterpretation. You explained everything and all of the rules of aromaticity were explained. I cannot see anything wrong with this post. I hope your grandma enjoyed the letter.

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