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Simple aromatic ring. Simple aromatic rings, also known as simple arenes or simple aromatics, are aromatic organic compounds that consist only of a conjugated planar ring system. Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules (" substituted aromatics").
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 circulating π electrons in an aromatic molecule produce ring currents that oppose the applied magnetic field in NMR. [9] The NMR signal of protons in the plane of an aromatic ring are shifted substantially further down-field than those on non-aromatic sp² carbons. This is an important way of detecting aromaticity.
Main arene substitution patterns. In ortho-substitution, two substituents occupy positions next to each other, which may be numbered 1 and 2. In the diagram, these positions are marked R and ortho. In meta-substitution the substituents occupy positions 1 and 3 (corresponding to R and meta in the diagram). In para-substitution, the substituents ...
Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated body armor fabric and ballistic composites, in marine cordage , marine hull reinforcement, as an asbestos substitute, [ 1 ] and in various lightweight consumer items ...
A diagram of an aromatic ring current. B 0 is the applied magnetic field, the red arrow indicating its direction. The orange ring shows the direction of the ring current, and the purple rings show the direction of the induced magnetic field. An aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene.
A nucleophilic aromatic substitution (SNAr) is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. Aromatic rings are usually nucleophilic, but some aromatic compounds do undergo nucleophilic substitution. Just as normally nucleophilic alkenes can be made ...
Hückel's rule. Benzene, the most widely recognized aromatic compound with six delocalized π-electrons (4 n + 2, for n = 1). In organic chemistry, Hückel's rule predicts that a planar ring molecule will have aromatic properties if it has 4 n + 2 π-electrons, where n is a non-negative integer. The quantum mechanical basis for its formulation ...