quinoid


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quin·oid

 (kwĭn′oid′)
n.
Quinonoid.

quin•oid

(ˈkwɪn ɔɪd)
adj.
1. quinonoid.
n.
2. a quinonoid substance.
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References in periodicals archive ?
Stilinovic, Schiff Bases Derived From Hydroxyaryl Aldehydes: Molecular And Crystal Structure, Tautomerism, Quinoid Effect, Coordination Compounds, Macedonian J.
8b exhibit a broad absorption tail between ~420 and ~800 nm for PEDOT/PEDOT, PEDOT/NaCl/PEDOT, and PEDOT/p/PEDOT ascribed to the polaronic band of the conductive quinoid form.
These SNPs located in or near genes ligand dependent nuclear receptor corepressor like, non-SMC condensin I complex subunit G (NCAPG), leucine aminopeptidase 3, LIM domain binding 2, quinoid dihydropteridine reductase, prominin 1, and transmembrane anterior posterior transformation 1.
The absorption band in 365 only appears at high levels of doping, because it comes from a combination of 360 e 440 nm bands, assigned to [pi]-[[pi].sup.*] transition of benzenoid segment and polaron-[pi] transition in quinoid rings, respectively.
The band of a pure PANI usually appears at 1294 [cm.sup.-1] ([u.sub.C-N] in secondary aromatic amine), 1555 [cm.sup.-1] ([u.sub.C-C], quinoid ring), 1469 [cm.sup.-1] ([u.sub.C-C], benzenoid ring), and 1120 [cm.sup.-1] (vibrational mode of B-N[H.sup.+] = Q structure) [2].
The structure of FvA has been proposed by many authors to be a mixture of covalently linked phenolic, quinoid, and benzene carboxylic acid compounds [6].
The resonant structure of the PEDOT changes from a benzenoid structure to a quinoid structure after adding a sugar alcohol [46] initiating an ordered planar backbone [47, 48].
Three characteristic absorption bands are observed in the spectra of pani at 269 nm, 368 nm and 618nm wavelength, n-Alpani composite had absorption peaks at 270 nm, 371 nm and 633nm which are attributed to [pi] -[[pi].sup.*]conjugated ring systems, polaron -[[pi].sup.*] and [pi]-polaron benzenoid to quinoid excitonic transition respectively.
The characteristic peaks of PANI from the Fig.8 were observed at 476.374 [cm.sup.-1] ( naphthalenes Out of plane ring bending), 800 [cm.sup.-1] (N-H out of plane bending absorption), 970 [cm.sup.-1] (C=C bending)[14], 1150 [cm.sup.-1] (C-H bending mode of Q ring, 1296 [cm.sup.-1]C-N stretching of secondary aromatic amine),1494 [cm.sup.-1](C=C stretching/C=N asymmetric stretching/C-H bending modes of benzenoid ring), 1560 [cm.sup.-1] (C=C stretching/C-H bending modes of quinoid ring)[15,16].
The presence of PEDOT:PSS could be confirmed with the peaks at the band of 1400-1500 [cm.sup.-1] resulting in the thiophene ring of PEDOT resonating between two states of benzoid and quinoid [28].
For lignocellulose fibers, degradation occurs because of UV radiation absorption by lignin, formation of quinoid structures, Norrish reactions, and reactions of photoyellowing, which make a significant contribution to discoloration (Beg and Pickering 2008, Butylina et al.