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In this section, only examples of antiaromatic compounds which are non-disputable are included. Pentalene is an antiaromatic compound which has been well-studied both experimentally and computationally for decades. It is dicyclic, planar and has eight π-electrons, fulfilling the IUPAC definition of antiaromaticity.
Hückel's rule is not valid for many compounds containing more than one ring. For example, pyrene and trans-bicalicene contain 16 conjugated electrons (8 bonds), and coronene contains 24 conjugated electrons (12 bonds). Both of these polycyclic molecules are aromatic, even though they fail the 4n + 2 rule. Indeed, Hückel's rule can only be ...
It is antiaromatic, because it has 4n π electrons where n is any integer. For this reason it dimerizes even at temperatures as low as −100 °C. [3] [4] The derivative 1,3,5-tri-tert-butylpentalene was synthesized in 1973. [5] Because of the tert-butyl substituents this compound is thermally stable.
Pages in category "Antiaromatic compounds" The following 13 pages are in this category, out of 13 total. This list may not reflect recent changes. ...
Annulenes may be aromatic (benzene, [6]annulene and [18]annulene), non-aromatic ([8] and [10]annulene), or anti-aromatic (cyclobutadiene, [4]annulene). Cyclobutadiene is the only annulene with considerable antiaromaticity, since planarity is unavoidable.
In contrast to the rarity of Möbius aromatic ground state molecular systems, there are many examples of pericyclic transition states that exhibit Möbius aromaticity. The classification of a pericyclic transition state as either Möbius or Hückel topology determines whether 4N or 4N + 2 electrons are required to make the transition state aromatic or antiaromatic, and therefore, allowed or ...
Rihanna and A$AP were notably missing from the 2025 Grammy Awards red carpet, but the reason why they skipped the ceremony makes sense.
In organic chemistry, thiepine (or thiepin) is an unsaturated seven-membered heterocyclic compound, with six carbon atoms and one sulfur atom. The parent compound, C 6 H 6 S is unstable and is predicted to be antiaromatic.