benzene ring


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ring

 [ring]
1. any annular or circular organ, structure, or area.
2. in chemistry, a collection of atoms united in a continuous or closed chain.
abdominal ring, external an opening in the aponeurosis of the external oblique muscle for the spermatic cord or round ligament.
abdominal ring, internal an aperture in the transverse fascia for the spermatic cord or round ligament.
Albl's ring a ring-shaped shadow in radiographs of the skull, caused by aneurysm of a cerebral artery.
Bandl's ring see bandl's ring.
benzene ring the hexagon representing the arrangement of carbon atoms in a molecule of benzene, different compounds being derived by replacement of the hydrogen atoms by different elements or compounds.
Cannon's ring a focal contraction seen radiographically at the mid-third of the transverse colon, marking an area of overlap between the superior and inferior nerve plexuses.
conjunctival ring a ring at the junction of the conjunctiva and cornea.
constriction ring a contracted area of the uterus, where the resistance of the uterine contents is slight, as over a depression in the contour of the fetus, or below the presenting part.
fibrous ring of heart anulus fibrosus.
halo ring a metal orthosis used for traction in the treatment of spinal cord injuries. The halo apparatus can maintain stability and alignment of the cervical vertebrae while the patient is out of bed.
inguinal ring, deep an aperture in the transverse fascia for the spermatic cord or the round ligament.
inguinal ring, external superficial inguinal ring.
inguinal ring, internal deep inguinal ring.
inguinal ring, superficial an opening in the aponeurosis of the external oblique muscle for the spermatic cord or the round ligament.
Kayser-Fleischer ring a golden brown or green discoloration in the zone of Descemet's membrane in the limbic region of the cornea seen in wilson's disease and other liver disorders.
pathologic retraction ring a complication of prolonged labor marked by failure of relaxation of the circular fibers at the internal opening of the cervix, obstructing delivery of the infant. See also bandl's ring.
physiologic retraction ring the demarcation between the upper, contracting portion of the uterus in labor and the lower, dilating part.
Schwalbe's ring a circular ridge composed of collagenous fibers surrounding the outer margin of Descemet's membrane.
tympanic ring the bony ring forming part of the temporal bone at birth and developing into the tympanic plate.
umbilical ring the orifice in the abdominal wall of the fetus for transmission of the umbilical vein and arteries.
vascular ring a congenital anomaly of the aortic arch and its tributaries, the vessels forming a ring about the trachea and esophagus and causing varying degrees of compression.

ben·zene ring

the closed-chain arrangement of the carbon and hydrogen atoms in the benzene molecule.
See also: cyclic compound.

benzene ring

n.
A hexagonal ring arrangement found in benzene and other aromatic compounds, consisting of six carbon atoms with alternating single and double bonds between them, and with each carbon atom bonded to a hydrogen atom, or to other atoms or groups of atoms in derivatives of benzene.

benzene ring

A closed aromatic structure composed of 6 carbon atoms linked with alternating single- and double-hydrogen bonds—2 atoms in the orbital and 1 atom in the π orbital.

ben·zene ring

(ben'zēn ring)
The closed-chain arrangement of the carbon and hydrogen atoms in the benzene molecule.
See also: cyclic compound

benzene ring,

benzene

a liquid hydrocarbon, C6H6, from coal tar; used as a solvent.

benzene hexachloride
a chlorinated hydrocarbon. The gamma isomer was used extensively as an insecticide. Called also Gammexane, lindane.
benzene hexachloride poisoning
benzene ring
the closed hexagon of carbon atoms in benzene, from which the different benzene compounds are derived by replacement of the hydrogen atoms.
References in periodicals archive ?
As a result, an increase in the magnitude of dipole moment and efficient charge transfer takes place from these dopants to the benzene rings.
While those in the Gas Service were also authorized to wear the new benzene ring and crossed retorts insignia, they were less than pleased with its design and symbolism.
Since the whole shape is symmetrical and interchangeable with a plane of symmetry, all hydrogen atoms of benzene ring are equivalent and at [delta] = 7.
Based on the solution P concentrations, it appears that benzoic and cinnamic acids behave as distinct groups, with the key differences in their structures being the distance of the carboxyl group from the benzene ring and the inclusion of a double-bond in the carboxyl side chain, both of which may influence their ability to form stable complexes with P in solution.
1] corresponding to the stretching vibration absorption peaks of C=C which belong to the quinone- and benzene rings, respectively; at around 1300 c [m.
As you increase the number of benzene rings in each molecule, you increase the power generated," said Bergfield.
1] indicates benzene ring obscured by -CH2- methylene bridge; 1058 corresponds to single bond C-O stretching vibrations of CH2OH group and 976 [cm.
74 were evident for 1,2,4-tri-substituted benzene ring moiety.
Finally, it could be seen from the above results and with respect to the structure of acylinium ion, that in the presence of electron donating substituents on benzene ring, rearrangement products, increase since stability of acylinium ion is related to the influence of these substituents and vice versa.
Adding other electron donors such as methyl to the benzene ring results in a variety of molecules within the window.
Chemist Friederich Kekule made his discovery of the benzene ring after dreaming of a snake with its tail in its mouth - these and other examples abound in the history of science.