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The C 3-benzenes are a class of organic aromatic compounds which contain a benzene ring and three other carbon atoms. For the hydrocarbons with no further unsaturation, there are four isomers. The chemical formula for all the saturated isomers is C 9 H 12 .
Structure and AFM image of dehydrobenzo[12]annulene, where benzene rings are held together by triple bonds. A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent single bond. Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond ...
Some results from these rules are worth being made explicit. Following Clar, [1] rules 1 and 2 imply that circles can never be in adjacent rings. Rule 3 means that only four options are viable for rings, namely (i) having only one double bond, (ii) having two double bonds, (iii) having a circle, or (iv) being empty, i.e. having no
Heteroarenes are aromatic compounds, where at least one methine or vinylene (-C= or -CH=CH-) group is replaced by a heteroatom: oxygen, nitrogen, or sulfur. [3] Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one ...
The trimethylbenzenes constitute a group of substances of aromatic hydrocarbons, which structure consists of a benzene ring with three methyl groups (–CH 3) as a substituent. [1] [2] Through their different arrangement, they form three structural isomers with the molecular formula C 9 H 12. They also belong to the group of C 3-benzenes.
Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules ("substituted aromatics"). Typical simple aromatic compounds are benzene, indole, and pyridine. [1] [2] Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur.
A Polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings.Most are produced by the incomplete combustion of organic matter— by engine exhaust fumes, tobacco, incinerators, in roasted meats and cereals, [1] or when biomass burns at lower temperatures as in forest fires.
The most widely practiced example of this reaction is the ethylation of benzene. Approximately 24,700,000 tons were produced in 1999. [ 73 ] Highly instructive but of far less industrial significance is the Friedel-Crafts alkylation of benzene (and many other aromatic rings) using an alkyl halide in the presence of a strong Lewis acid catalyst.