CHEM 228 Chapter 15: Chapter 15 Book Notes

• School: Texas A&M University
• Department: Chemistry
• Course: CHEM 228
• Professor: Santander Patricio

Document Summary

Huckel rule (4n+2): a rule stating that monocyclic conjugated molecules having 4n+2 pi electrons are aromatic. Delocalization of the pi electrons leads to an increase in energy. Aromatic ions can be larger or smaller than a six-membered ring and still be considered aromatic based off the charge of the molecule. Both hydrogens removed = cation one hydrogen removed = carbon radical. Heterocycle: a cyclic molecule whose ring contains more than one kind of atom. For example, pyridine is a heterocycle that contains ve carbon atoms and one nitrogen atom in its ring. These nitrogens are double bonded and only one pi electron is contributed to the aromatic sextet. Huckel rule is only strictly applicable to monocyclic compounds, but the general concept of aromaticity can be extended to include polycylic aromatic compounds.