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- Aromatic_ring_current abstract "An aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene. If a magnetic field is directed perpendicular to the plane of the aromatic system, a ring current is induced in the delocalized π electrons of the aromatic ring. This is a direct consequence of Ampère's law; since the electrons involved are free to circulate, rather than being localized in bonds as they would be in most non-aromatic molecules, they respond much more strongly to the magnetic field.Aromatic ring currents are relevant to NMR spectroscopy, as they dramatically influence the chemical shifts of 13C and 1H nuclei in aromatic molecules, as well as in any organic or inorganic aromatic molecule. The effect helps distinguish these nuclear environments and is therefore of great use in molecular structure determination. In benzene, the ring protons experience deshielding because the induced magnetic field has the same direction as the external field and their chemical shift is 7.3 ppm compared to 5.6 to the vinylic proton in cyclohexene. In contrast any proton inside the aromatic ring experiences shielding because both fields are in opposite direction. This effect can be observed in cyclooctadecanonaene ([18]annulene) with 6 inner protons at −3 ppm. The situation is reversed in antiaromatic compounds. In the dianion of [18]annulene the inner protons are strongly deshielded at 20.8 ppm and 29.5 ppm with the outer protons significantly shielded (with respect to the reference) at −1.1 ppm. Hence a diamagnetic ring current or diatropic ring current is associated with aromaticity whereas a paratropic ring current signals antiaromaticity.A similar effect is observed in three-dimensional fullerenes; in this case it is called a sphere current.".
- Aromatic_ring_current thumbnail Aromatic-ring-current.png?width=300.
- Aromatic_ring_current wikiPageID "4401137".
- Aromatic_ring_current wikiPageRevisionID "544319545".
- Aromatic_ring_current hasPhotoCollection Aromatic_ring_current.
- Aromatic_ring_current subject Category:Electric_current.
- Aromatic_ring_current subject Category:Nuclear_magnetic_resonance.
- Aromatic_ring_current comment "An aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene. If a magnetic field is directed perpendicular to the plane of the aromatic system, a ring current is induced in the delocalized π electrons of the aromatic ring.".
- Aromatic_ring_current label "Aromatic ring current".
- Aromatic_ring_current label "Corrente de anel aromático".
- Aromatic_ring_current label "環電流".
- Aromatic_ring_current sameAs 環電流.
- Aromatic_ring_current sameAs Corrente_de_anel_aromático.
- Aromatic_ring_current sameAs m.0c07cj.
- Aromatic_ring_current sameAs Q4795520.
- Aromatic_ring_current sameAs Q4795520.
- Aromatic_ring_current wasDerivedFrom Aromatic_ring_current?oldid=544319545.
- Aromatic_ring_current depiction Aromatic-ring-current.png.
- Aromatic_ring_current isPrimaryTopicOf Aromatic_ring_current.
