Influence of naphthoquinone dyes on electrooptical properties of liquid crystals

Probing the Mesoscopic Chemical and Physical Properties of Polymer-Dispersed Liquid Crystals

“…Avenues for improvement might include the synthesis of new liquid crystal and polymer materials. [78] Progress will continue to be made along existing paths as well, by incorporation of dyes, [8,53,54] surfactants, [71,72,160] and other ionic dopants [73±75,77,81] into these materials. Finally, a bright future exists for applications of PDLC materials as electrically switchable holographic diffraction gratings.…”

“…Film composition can vary on very short distance scales and can change over long periods of time. [70] Also of importance are issues associated with the addition of dyes, [8,53,54] surfactants, [71,72] and/or other ionic dopants.…”

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

“…The N -phenylquinone imines are considered as an important class of compounds because of their properties as dyes for optical devices [ 15 ], antioxidants [ 16 ], anticancer agents [ 17 ] and precursors of liquid crystalline materials [ 18 ]. With regard to the synthesis of N -phenyl-1,4-naphthoquinone monoimines, Bukhtoyarova et al [ 19 ], has described their preparation by reaction of 1,5-DHN ( 1 ) with phenylamines using oxidants such as K 3 Fe(CN) 6 , HIO 3 and NaIO 4 in aqueous alcohol.…”

Synthesis of 2,4,6,8-Tetrasubstituted 1,5-Naphthoquinones

“…The oxidation of arylthio groups in 4,8-di(arylamino)-2,6-di(4-tert-butylphenylthio)-1,5-naphthoquinones VIIa and VIIc with m-chloroperbenzoic acid in chloroform by procedure [11] afforded tetrasubstituted 1,5-naphtho-SYNTHESIS OF 2,4,6,8-TETRASUBSTITUTED 1,5-NAPHTHOQUINONES Compounds IIc, IV, VIIa, VIIc, and VIId were tested as dichroic dyes in the liquid-crystal composites [14]. It was shown that the introduction of 4-tert-butylphenylthio groups into positions 2 and 6 of 4,8-di(arylamino)-1,5-naphthoquinones (compounds VIIa, VIIc, and VIId) resulted in increased value of the order parameter S and increased contrast of the composites.…”