Benzene rings symbol

It may also be represented as a hexagon with a circle in the middle. The circle is a symbol of the n cloud encircling the benzene ring. The delocalized electrons associated with the benzene ring impart very special properties to aromatic hydrocarbons. They have chemical properties of single-bond compounds such as paraffin hydrocarbons and doublebond compounds such as olefins, as well as many properties of their own. 

Mahdihassan, S. The probable origin of Kekule s symbol of the benzene ring. Scientia 54 (1960) 1-6. 

The mechanism of the reaction depicted in Scheme 4.6 differs from the Sf.,1 or Sf.,2 mechanism in that it involves the stage of one-electron oxidation-reduction. The impetus of this stage may be the easy detachment of the bromine anion followed by the formation of fluorenyl radical. The latter is unsaturated at position 9 near three benzene rings that stabilize the radical center. The radical formed is intercepted by the phenylthiolate ion. This leads to the anion-radical of the substitution product. Further electron exchange produces the substrate anion-radical and final product in its neutral state. The reaction consists of radical (R)-nucleophilic (N) monomolecular (1) substitution (S), with the combined symbol Sj j l. Reactions of Sj j l type can have both branch-chain and nonchain characters. 

The benzene rings in the helicenes are indexed by letters as shown. Sometimes helicenes are indicated by short nomenclature symbols, via the number of the con-... 

Other symbols as shown below are representations of the benzene ring. 

Nowadays it is very difficult to pinpoint in the classical literatures in organic chemistry the credit of attributing the relative stability of unsaturated hydrocarbon molecules to K(G) [2, 3], On the other hand, long before these quantum-chemical theories were introduced Robinson proposed using a circle inside each benzene ring of an aromatic hydrocarbon molecule to represent the six mobile electrons and also the derived aromatic stability [4], However, his symbol does not reflect any difference in the stability between I and II as,... 

By this designation the four atom-four bond (three actual and one virtual) system should be regarded in much the same manner as the abbreviation PhH for the benzene ring (C6H6) in the metallocenes in Chapter 6. One difference, however, is that this functional symbol indicates not only that the pseudo-ring has two distinct forms (keto and enol) but also it canonically assigns locant numbers to the atoms, bonds and substituent R groups. 

Additionally, one is unable to use the functional Ph symbol to advantage due to the fusing of benzene rings, rather than having them connected in ring assembly fashion. 

When a benzene ring is attached to a molecule by only one of its carbon atoms (as in phenylalanine, but not paracetamol or aspirin), we can call it a phenyl group and give it the organic element symbol Ph. 

An exceptionally stable cation is formed when three benzene rings can help to stabilize the same positive charge. The result is the triphenylmethyl cation or, for short, the trityl cation. The symbol Tr (another of these organic elements ) refers to the group Ph3C. Trityl chloride is used to form an ether with a primary alcohol group by an SnI reaction. Here is the reaction. 

A benzene ring can be written with three alternating double bonds or with a circle in the ring. All of the carbons and hydrogens in an unsubstituted benzene ring are equivalent, regardless of which symbolism is used. 

When a hydrogen atom is removed from a benzene ring, this is a phenyl group. The symbol Ph is used to represent this. 

Pertritiated methane (produced by the reaction of aluminum carbide with T2O) yields tritiated methyl cations (symbolized as CTj"), whose gas phase chemistry has been extensively studied by Nefedov s group in Russia. One of their first major contributions was to provide evidence for methyl migration around protonated benzene rings, as summarized in Table In mixtures of xylenes (at their vapor pressure) and pertritiated methane,... 

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