Hetero Cyclic Aromatic Compounds

Heterocyclic Aromatic Compounds So far we have only considered carbon skeleton compounds. However, many compounds we find in nature are cyclic compounds with an element other than carbon in the ring. These are called Heterocyclic compounds. Further, some are aromatic compounds - can be termed heteroaromatic.

However, the degree of aromaticity (extra stability) may vary as the heteroatom changes. In electronic terms pyridine is related to benzene.

Pyrrole has electrons arranged differently – related to the cyclopentadienyl anion.

(Similar electronic configurations for furan and thiophene)

Aromatic hydrocarbon From Wikipedia, the free encyclopedia

Jump to: navigation, search "Arene" redirects here. For other uses, see Arene (disambiguation). An aromatic hydrocarbon (abbreviated as AH) or arene [1] (or sometimes aryl hydrocarbon[2]) is a hydrocarbon, of which the molecular structure incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent. The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible such hydrocarbon, benzene. Aromatic hydrocarbons can be monocyclic or polycyclic. Some non-benzene-based compounds called heteroarenes, which follow Hückel's rule, are also aromatic compounds. In these compounds, at least one carbon atom is replaced by one of the heteroatoms oxygen, nitrogen, or sulfur. Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a fivemembered ring that includes an oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one nitrogen atom.[3]