What is the requirement for #"aromaticity"#? Why is cyclohexane non-aromatic?

1 Answer
anor277
Jul 7, 2016

A requirement for aromaticity is #4n+2# #pi# electrons

Explanation:

Benzene, #C_6H_6#, certainly meets this criterion; so does pyridine, #C_5H_5N#, and pyrrole, #C_4H_5N#, and furan, #C_4H_4O#, and thiophene, #C_4H_4S#. Cyclohexane has no #pi# electrons, and cyclohexene and cyclohexadiene have #2# and #4# #pi# electrons respectively.

The 5-membered ring aromatic heterocycles are so-called #pi-"excessive"# species, whose reactivity in electrophilic substitution is enhanced.

Related questions
See all questions in Quick Introduction of Structures
Impact of this question
1279 views around the world
You can reuse this answer
Creative Commons License