quinone

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quin·one

(kwin'ōn, kwī'nōn),
1. General name for aromatic compounds bearing two oxygens in place of two hydrogens, usually in the para position; the oxidation product of a hydroquinone.
2. Synonym(s): 1, 4-benzoquinone (1)

quinone

/qui·none/ (kwi´nōn) (kwin´ōn) any of a group of highly aromatic compounds derived from benzene or from multiple ring hydrocarbons and containing two ketone group substitutions; they are subclassified on the basis of ring structure (i.e., anthraquinone, benzoquinone) and are mild oxidizing agents. Often used specifically to denote benzoquinone, particularly 1,4-benzoquinone.

quinone

(kwĭ-nōn′, kwĭn′ōn′)
n.
1. Either of two isomeric unsaturated cyclic compounds having the formula C6H4O2, found widely in plants, especially in a yellow crystalline form, and used in making dyes, tanning hides, and photography.
2. Any of various quinonoid compounds, often yellow to red in color, many of which have biological derivation or importance, such as coenzyme-Q.

quinone

(1) 1,4-Benzoquinone, see there.  
(2) An aromatic compound with two oxygens substituted for two hydrogens.

quinone

any of the various compounds derived from benzene.
References in periodicals archive ?
1] can be assigned to the in-plane deformation of the C-C bond of the quinoid ring and C-C stretching of the quinoid ring, respectively.
At higher doping level the excess CSA saturates the 1, 4 positions of the quinoid ring resulting in their strong effects on the charge distribution on the chains leading to the structural distortion [32].
The first band is associated with the [PI]--[PI]* transition of the conjugated ring systems and the second is with the benzenoid to quinoid excitonic transition (37).
1] represent C=C stretching vibrations of the quinoid and benzoid rings, respectively, in the PANI.
The benzoid and quinoid absorption peaks of PANI-DBSA shift to lower wavenumbers after doping due to the created positive charge around the backbones.
1] are related to C--N stretching mode for the quinoid and benzenoid units [6, 11, 14, 22].
Generally, the characteristic peaks of undoping PANI is at 1600 and 1510 (C--C stretching for quinoid and benzenoid groups), 1301 and 1176 (C--N) (KBr, thin film, [cm.
1] (C = C stretching of the quinoid ring), 1469 [cm.
The active compounds, which have been isolated and identified, belong to the classes of alkaloids (68), triterpenes (29), sesquiterpenes (19), miscellaneous lactones (18), quinoids (16), flavonoids (13), diterpenes (13), steroids (10), lipids (8), iridoids (8), oxygen heterocycles (7), benzenoids (6), carbohydrates (5), lignans (5), proteids (4), coumarins (3), phenylpropanoids (3), depsides (2), a sulfur compound (1), and a monoterpene (1).
Of the 69 compounds which have been isolated and identified (Table 3 and 4) and are available for ovarian neoplasias, 25 are alkaloids, 8 non-alkaloid N-heterocycles, 7 miscellaneous lactones, 4 proteids, 4 diterpenes, 4 anthraquinones, 3 peptides, 2 quinoids, 2 triterpenes, 2 sesquiterpenes, 2 flavonoids, 2 lignans, 1 carbohydrate, 1 carotenoid, I anthracene and 1 benzenoid.