IdahoDoc

10+ Year Member
7+ Year Member
Aug 26, 2007
500
1
Status
Dental Student
I can't find the difference. In the ACS guide it doesn't explain them as different but in destroyer it says they are. Can some one please explain?
 

ekl1984

10+ Year Member
Nov 19, 2008
10
0
Status
Dental Student
Aromatic compounds are cyclic, conjugated polyenes with planar configuration. They follow Huckel's rule (meaning that they must have 4n + 2 pi electrons (n = any nonnegative integer)). So for example benzene is aromatic because it has 6 pi electrons (n = 1). Antiaromatic compounds are cyclic, conjugated polyenes with planar configuration, that have 4n pi electrons..
.
 

IdahoDoc

10+ Year Member
7+ Year Member
Aug 26, 2007
500
1
Status
Dental Student
Aromatic compounds are cyclic, conjugated polyenes with planar configuration. They follow Huckel's rule (meaning that they must have 4n + 2 pi electrons (n = any nonnegative integer)). So for example benzene is aromatic because it has 6 pi electrons (n = 1). Antiaromatic compounds are cyclic, conjugated polyenes with planar configuration, that have 4n pi electrons..
.
I guess i just don't understand huckel's rule the 4n+2... Where do you get the "n" from???
 
About the Ads

ekl1984

10+ Year Member
Nov 19, 2008
10
0
Status
Dental Student
Oh sorry, I forgot to explain non-aromatic compounds. They are conjugated polyenes that do not fall into the category of aromatic or antiaromatic. Either because they do not possess either 4n + 2 or 4n pi electrons, or because they are not planar or completely conjugated. So for example cyclooctatetrane (conjugated 8 member ring) is non-aromatic because even though it has 4n electrons, it is not planar.
 

ekl1984

10+ Year Member
Nov 19, 2008
10
0
Status
Dental Student
The best way to get n is to start by counting how many pi electrons there are in the compound. (Double bonds and electron pairs count for 2, heterocyclic atoms are a bit trickier). Then take the number of pi electrons in the compound subtract 2 and then divide by 4. That will give you n, if it is a positive integer or zero, then the compound is aromatic.
 

IdahoDoc

10+ Year Member
7+ Year Member
Aug 26, 2007
500
1
Status
Dental Student
ill give it a try thanks
 
About the Ads