Search results
Results From The WOW.Com Content Network
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 ...
The compound is the prototypical antiaromatic hydrocarbon with 4 pi electrons (or π electrons). It is the smallest [n]-annulene ([4]-annulene).Its rectangular structure is the result of a pseudo [3] - (or second order) Jahn–Teller effect, which distorts the molecule and lowers its symmetry, converting the triplet to a singlet ground state. [4]
Two different resonance forms of benzene (top) combine to produce an average structure (bottom). In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugation alone.
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.
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. ...
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.