Talk:Cyclooctatetraene

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Aromaticity[edit]

I would say that this molecule is indeed NOT aromatic. This is further reinforced by Raman spectroscopy:

THOMAS PM, WEBER A, HIGH-RESOLUTION RAMAN-SPECTROSCOPY OF GASES WITH LASER SOURCES .13. PURE ROTATIONAL SPECTRA OF 1,3,5,7-CYCLOOCTATETRAENE AND 1,5-CYCLOOCTADIENE JOURNAL OF RAMAN SPECTROSCOPY 7 (6): 353-357 1978 —Preceding unsigned comment added by 141.30.87.47 (talk) 14:06, 7 January 2008 (UTC)[reply]

Yes. The introduction to the article states "cyclooctatetraene, C8H8, is not aromatic.", and there is explanation and some refs in the "Structure and Bonding" section of the article. Do you have this article handly? Might be good to add it to the article, mentioning what specifically it found about the structure (non-planarity, non-uniform bond-lengths, etc). DMacks (talk) 15:33, 7 January 2008 (UTC)[reply]

How non-planar is it?[edit]

A useful piece of data would be the π–π dihedral angle (the single-bond rotation), indicating just how far from planar COT is. At least some work on solving the X-ray structure has been done (Kaufman, H. S.; Fankuchen, I.; Mark, H. (1947). "An X-Ray Examination of Cyclooctatetraene". J. Chem. Phys. 15 (6): 414–415. doi:10.1063/1.1746544.{{cite journal}}: CS1 maint: multiple names: authors list (link)) but no actual atomic or structural coordinates are in that ref. Maybe an article that cites it would have them? DMacks (talk) 21:54, 7 January 2008 (UTC)[reply]

There are some coordinates deposited in the Cambridge Structural Database with code ZZZSAE01. The reference is K.H.Claus, C.Kruger. Acta Crystallogr.,Sect.C:Cryst.Struct.Commun. 1988, 44, 1632. I downloaded the coordinates and measured the dihedrals, and they are all about 56 deg (to be precise, 55.40, -57.98, 55.40, -56.65). --Itub (talk) 15:40, 9 January 2008 (UTC)[reply]

Semibullvalene as structural isomer[edit]

The See also section of the article claimed that semibullvalene is a structural isomer of cyclooctatetraene. However, according to the Semibullvalene article, that molecule has ten carbon atoms, whereas cyclooctatetraene has eight. I will remove this claim, but as I'm not really good in chemistry, feel free to reinstate it if I'm wrong. – b_jonas 21:03, 24 February 2013 (UTC)[reply]

why is this in the "antiaromatic" category?[edit]

It would be so if it were planar, but it is not. It is simply nonaromatic, precisely to avoid the stability that comes as a natural part of being antiaromatic. Double sharp (talk) 13:07, 5 November 2016 (UTC)[reply]

You are correct, but "people" often call COT antiaromatic or discuss the molecule in that context. I dont have any strong views, on the categories. --Smokefoot (talk) 21:21, 5 November 2016 (UTC)[reply]
As you say, it adopts a non-planar arrangement in order to not be antiaromatic. The Cat is a list of such odd things. Strictly speaking I don't think there are any observable antiaromatic compounds, they're just too unfavourable, anything capable of it normally adopts a skewed geometry, or is unbelievably reactive. --Project Osprey (talk) 17:18, 6 November 2016 (UTC)[reply]

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