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 ?
PMMA also lacks the carbon-rich benzene rings found in polystyrene.
2] and the benzene ring that attached to oxazine, respectively, do not change after heat treatment of 135[degrees]C.
In fact, the increase in the electron donating power of substituents on the ortho-, meta- and para- positions of benzene ring notably increases the yields of the ortho-OH(D) isomers and also conversely, the increase in electron withdrawing power of the substituents on the ortho-, meta- and para- positions of benzene ring remarkably affects the rearrangement and ortho-OH(D) isomers are not produced.
1]) 1 3300 Bonded O-H stretching 2 2900 C-H stretching 3 1730 C=O stretching in xylan 4 1660 Keto-carbonyl conjugated with benzene ring 5 1600 Benzene ring stretching in lignin 6 1505 Benzene ring stretching in lignin 7 1460 C[H.
It is also evident that substitution in the para-position of the benzene ring by hydroxy or methoxy group increases the accelerating efficiency of these compounds.
During this process, the tri-substituted benzene ring and the backbone of the benzoxazine ring became tetrasubstituted structure.
Approved in December 1917, the new insignia--a benzene ring superimposed in the center of crossed retorts--reflected the scientific origin of chemical warfare.
Numerous approaches are adopted for the synthesis of acridone derivative with varied substitution on central benzene ring and at side rings to enhance their antimicrobial potential.
1)) Assignments PPMPCE 1677 Conjugated C=N stretching vibration 1607, 1504, Benzene ring 1459 backbone stretching vibrations 3074, 3121 Aromatic C[sbond-H stretching vibration 1206, 1028, X32 p-Substituted benzene ring 2838.
The benzene ring is not easily destroyed in the body, and Knoop expected it to show up in the urine.
In these three crystals, the planes between imidazole ring and the substituted benzene ring are not co-plane and the intersection angles are 65.