Ochem Help???

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

Beagle

Meet BEAGLE
7+ Year Member
15+ Year Member
20+ Year Member
Joined
Jul 17, 2001
Messages
596
Reaction score
0
Can someone explain Huckal's rule to me?
I have no idea how to find out of a molecule is aromatic or not.
Kaplans book isn't of much help with this stuff(to me anyway)
Thanks !!!
 
From my understanding you can use huckles rule if you see all of the aromatic compounds are cyclic (joined) and conjugated then you can use 4n+2 (Huckles rule) so if you had a benzene ring with 3 double bonds you know that those three double bonds have 6 e- so you can put the equation like this:

6=4n+2
-2 -2
________
4=4n

4/4 =n

n = 1

so benzene is aromatic since n= a whole number

If there was a cyclic compound with 8 e- or 4 double bonds then the equation would be:


8=4n+2
-2 -2
________

6=4n

6/4 =n which is not a whole number, thus not aromatic. But use huckles rule only after ruling out the first two criteria:

1.) cyclic
2.) conjugation

Hope this helps,

DesiDentist
 
Top