benzene ring

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Related to benzene rings: benzoic acid, toluene

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
References in periodicals archive ?
Since the molecular formula afforded 19 carbon atoms, the resonances of only eight carbon nuclei in the 13C NMR spectrum substantiated symmetrical dimeric nature of 2 with two p-substituted benzene rings. Thus the combination of the above spectroscopic data with HMBC (Figure 2) information, compound 2 was finally characterized as bis[di-p-phenylmethane]ethyl carbamate, which is also a new natural carbamate derivative.
The analysis found a higher occurrence of components with the 1,720 (hydrocarbon oxides) and 1,600 [cm.sub.-1] (benzene ring polymers) wavenumbers.
was promoted by substituting the electron-donating substituent on the benzene ring of phenylhydrazone (the opposite is also true).
In the [.sup.1.H]-NMR spectrum, aromatic doublet protons at [delta] 7.01 (2H) and [delta] 6.66 (2 H) indicated that 4 had an 1,4-di-substituted benzene ring. The coupling patterns at [delta] 6.24 and 6.02 (d, J = 12.2 Hz each) suggested the existence of cis-olefinic protons.
The second complex (c), where the [Cs.sup.+] interacts with the lone-pair electrons of both oxygen atoms and is lying at an almost equal distance from them in the plane of the benzene ring, is energetically less stable by 1.4 kcal/mol.
PMMA also lacks the carbon-rich benzene rings found in polystyrene.
The benzamide derivatives with morpholine or benzene rings reveal no antifungi activity.
As a result, an increase in the magnitude of dipole moment and efficient charge transfer takes place from these dopants to the benzene rings. In POA, the presence of large number of donor groups like NH and OC[H.sub.3], in turn enhances the charge transfer.
The calculation results indicate that in the [alpha]-CD inclusion complex only one of the DE benzene rings inserts into the CD, while the hexafuluoro-cyclopentene group protrudes into the solution.
A compound containing benzimidazole and benzene rings have been used extensively for pharmaceutical purpose since 1960.
He next tried to attach six benzene rings to two carbon atoms hooked together, thus forming hexaphenylethane.