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2D model of a benzene molecule. The carbon "ring" is what makes benzene "aromatic". Aromatic compounds or arenes are organic compounds "with a chemistry typified by benzene" and "cyclically conjugated." [1] The word "aromatic" originates from the past grouping of molecules based on odor, before their general chemical properties were understood ...
Benzene is an organic chemical compound with the molecular formula C 6 H 6. The benzene ... based on preventing benzene ... of benzene and other aromatic petroleum ...
Benzene, the most widely recognized aromatic compound with six delocalized π-electrons (4n + 2, for n = 1). In organic chemistry, Hückel's rule predicts that a planar ring molecule will have aromatic properties if it has 4n + 2 π-electrons, where n is a non-negative integer.
The theory predicts the molecular orbitals for π-electrons in π-delocalized molecules, such as ethylene, benzene, butadiene, and pyridine. [ 1 ] [ 2 ] [ 3 ] It provides the theoretical basis for Hückel's rule that cyclic, planar molecules or ions with 4 n + 2 {\displaystyle 4n+2} π-electrons are aromatic .
When carbon in benzene is replaced by other elements in borabenzene, silabenzene, germanabenzene, stannabenzene, phosphorine or pyrylium salts the aromaticity is still retained. Aromaticity also occurs in compounds that are not carbon-based at all. Inorganic 6-membered-ring compounds analogous to benzene have been synthesized.
In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho – (or o –), meta – (or m –), and para – (or p –) as indicated in the adjacent diagram.
Clar's rule states that for a benzenoid polycyclic aromatic hydrocarbon (i.e. one with only hexagonal rings), the resonance structure with the largest number of disjoint aromatic π-sextets is the most important to characterize its chemical and physical properties. Such a resonance structure is called a Clar structure. In other words, a ...
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 ...