About Aromatic compound,,,,!!!
Started by potbelly
There's Huckel's rule, part of which is anything aromatic needs to have 4n+2 pi bonding electrons or something like that. Since it has 4 double bonds, that's 8 electrons, so it doesn't match 4n+2, it's 4n, so it's anti.
Pretty sure that's right!
EDIT: I'm wrong, see my posts below, it's non-aromatic.
Pretty sure that's right!
EDIT: I'm wrong, see my posts below, it's non-aromatic.
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Yep BB is right, based on 4n+2 its an anti aromatic compound.
I think you are right.. Thanks.. Since this compound is not planar, it can't be anti-aromatic even though it has 4n pi electrons... Thus it is non- aromatic as you said! Thank you!
Yeah, I think he is right that it's non-planar. Now that I'm thinking about what the structure looks like, I'm pretty sure I remember that as one of the ones that's an exemption from 4n+2 because of it's shape. So, I think I change my answer to non-aromatic!
that structure would be anti-aromatic. In order for a cyclic compound to be aromatic or anti-aromatic it should follow these 4 rules:
1) Conjugation of double bonds.
2) each atom in the ring must have a free p-orbital
3) continuous overlap of the free p-orbitals
4) Huckel's Rule: 4n+2= aromatic, 4n= anti-aromatic.
If the ring doesn't follow any of the first three than it is non-aromatic. A cyclooctane with four conjugated double bonds follows the first three rules and the 4n rule therefore it is antiaromatic.
1) Conjugation of double bonds.
2) each atom in the ring must have a free p-orbital
3) continuous overlap of the free p-orbitals
4) Huckel's Rule: 4n+2= aromatic, 4n= anti-aromatic.
If the ring doesn't follow any of the first three than it is non-aromatic. A cyclooctane with four conjugated double bonds follows the first three rules and the 4n rule therefore it is antiaromatic.
why do u guys make it difficult!
as smurf confirmed it too its anti aromatic.
just to assure u, it has 8 sides with 4 conj double bonds. it does not have any sp3 carbons thus it has an uninterrupted pi system. and it follows the 4n formula.
as smurf confirmed it too its anti aromatic.
just to assure u, it has 8 sides with 4 conj double bonds. it does not have any sp3 carbons thus it has an uninterrupted pi system. and it follows the 4n formula.
http://en.wikipedia.org/wiki/File:COT-all-cis.png
It's IUPAC name is 1,3,5,7-Cyclooctatetraene. Take a look at that picture, it shows that it is non-planar, and for it to be either anti-aromatic OR aromatic, it must be planar. Thus, it is non-aromatic. See what I mean?
It's IUPAC name is 1,3,5,7-Cyclooctatetraene. Take a look at that picture, it shows that it is non-planar, and for it to be either anti-aromatic OR aromatic, it must be planar. Thus, it is non-aromatic. See what I mean?
I just took my orgo 2 exam on aromaticity and that my friends in non aromatic. when u have a ring that big with all cis bonds, especially if its a 8annalene or above it will end up taking on a more favorable conformation, one that is non aromatic.
okay. This has got me a bit frustrated so I did some reading out of my OChem textbook. cyclooctatetraene can be either anti or non depending if Huckel's rule applies or not. This is what the text says:
"Cyclooctatetraene would be antiaromatic if Huckel's rule applied, so the conjugation of its double bonds is energetically unfavorable. Remember that Huckel's rule applies to a compound only if there is a continuous ring of overlapping p orbitals, usually in a planar system. Cyclooctatetraene is more flexible than cyclobutadiene, and it assumes a nonplanar "tub" conformation that avoids most of the overlap between adjacent pi bonds. Huckel's rule simply does not apply." Organic Chemistry. 6th Edition, 2006. Wade L.G.
Huckel's Rule = antiaromatic
No Huckel's Rule = nonaromatic
"Cyclooctatetraene would be antiaromatic if Huckel's rule applied, so the conjugation of its double bonds is energetically unfavorable. Remember that Huckel's rule applies to a compound only if there is a continuous ring of overlapping p orbitals, usually in a planar system. Cyclooctatetraene is more flexible than cyclobutadiene, and it assumes a nonplanar "tub" conformation that avoids most of the overlap between adjacent pi bonds. Huckel's rule simply does not apply." Organic Chemistry. 6th Edition, 2006. Wade L.G.
Huckel's Rule = antiaromatic
No Huckel's Rule = nonaromatic
