142450-58-6Relevant articles and documents
Synthesis and luminescent studies of poly(phenylenevinylene)s containing a biphenyl moiety
Sarker, Ananda M.,Ding, Liming,Lahti, Paul M.,Karasz, Frank E.
, p. 223 - 230 (2002)
The polymers discussed in this contribution consist of phenylenevinylene chromophores linked together across flexible biphenyl hinges to shorten the effective conjugation length and to give sufficiently twisted structures that interchain aggregation is limited or prevented. They are poly[(2,5- dihexyloxy-p-phenylenevinylene)-alt-(4,4′-dihexyloxy-3, 3′-biphenylenevinylene)] (1), poly[(2,5-dihexyloxy- p-phenylenevinylene)-alt-(2,2′-dihexyloxy-3,3′ -biphenylenevinylene)] (2), and poly[(2,5-dihexyloxy-p- phenylenevinylene)-alt-(2,2′-biphenylenevinylene)] (3). Absorption spectra in dilute solution and solid states are very similar for 1-3, consistent with the absence of aggregation effects in their ground electronic states. Photoluminescence emission spectra showed substantial red shifts in the solid state relative to dilute solution phase spectra. Solution emission quantum yields ranged from 0.26 to 0.42. LEDs based on 1-3 gave blue-green emission with maxima in the 480-510 nm range. The similarity of the photoluminescence and electroluminescence spectra for the polymers is consistent with emission from the same or very similar excited-state species. For LEDs based upon the highest quantum efficiency photoluminescent emitter, 1, better luminance was achieved using PEDOT-PSS hole injection layers in double-layer LEDs than using PPV.
Rewritable color recording media consisting of leuco dye and biphenyl developer with a long alkyl chain
Naito, Katsuyuki
, p. 1379 - 1384 (1998)
Media formulated using two compounds (a leuco dye and 4-alkoxyl-4′-hydroxybiphenyl) were colored in the amorphous state and colorless in the crystalline state. As the alkyl chain length of the biphenyl compound increased, the contrast ratio and thermal stability of the amorphous states increased. Additionally, the crystallization velocity increased for the media with a long alkyl chain. Leuco dyes with a high glass transition temperature also produced thermally stable amorphous states. The origin of the long alkyl chain effects is discussed.
Design and synthesis of novel calamitic and discotic materials based on the photorefractive carbazole unit
Manickam,Iqbal,Spencer,Ashton,Kumar,Donovan,Preece
experimental part, p. 84 - 100 (2011/05/03)
The incorporation of photorefractive molecular units, such as carbazole, into anisotropic materials (liquid crystals) may offer many advantages over conventional electrical poling of photorefractive polymers. Thus, a series of symmetric 3,6-disubstituted
Synthesis, structure, and mesomorphic properties of liquid crystals with a bitropone core
Kubo, Kanji,Sutoh, Takanori,Mori, Akira,Ujiie, Seiji
, p. 1353 - 1358 (2007/10/03)
New troponoid liquid crystals (1-4) with a bitropone core were prepared. The ester derivatives (1) had enantiotropic smectic A and/or C phases with higher thermal stabilities than the corresponding benzenoid derivatives (5), which had a smectic B phase. T
Selective etherification of polyhydroxybenzenes using PEG 200 as solvent or cosolvent
Berdague, P.,Perez, F.,Courtieu, J.,Bayle, J. P.
, p. 475 - 480 (2007/10/02)
The monoalkylation of hydroquinone is performed using PEG 200 as a solvent or a cosolvent.The effect on the selectivity of the base strength, the temperature, and the percentage of cosolvent are discussed.The substituted phenols were found to behave differently upon etherification.When a carboxylic function is present in the ring, the hydroxybenzoic acids were selectively etherified using pure PEG and sodium hydroxyde as a base.Substituted diphenols were selectively etherified using a mixture of PEG and dioxan and potassium hydrogencarbonate as a base.Keywords - etherification / selectivity / polyhydroxybenzenes / polyethylene glycol
