摘要:

We report an observation of a new wavelength- and angle-selective optical memory effect caused by interference of multiple-scattered light in polystyrene powder doped with a fluorescent fulgide derivative. This effect is applicable to three-dimensional optical data storage.

ISSN:1058-725X    

DOI:10.1080/10587250008023837

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A novel method of thin film formation of organic materials using a vacuum technique is proposed. An organic dye with a high sublimation pressure is loaded in a crucible along with a thin polymer film. After pumping down, the crucible is sealed, then placed in a constant temperature oven. The vapor of dye dissolves into the polymer film, thus forming a thin dye-containing layer.

ISSN:1058-725X    

DOI:10.1080/10587250008023838

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Photochromic naphthopyrans are of particular interest due to their wide use in applications such as switchable eyewear, security devices and novelty items. The spectral properties of the activated form are important in many of these applications. This paper reports the effect of substituents on the visible absorption of the activated form(s). In addition to color, other photochromic properties of naphthopyrans are briefly discussed.

ISSN:1058-725X    

DOI:10.1080/10587250008023839

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

(R)-Binaphthol-condensed benzofurylfulgide3was synthesized and its photochromic properties as well as the change in other properties associated with photochromism were investigated. Like its indole analogue1, 3showed diastereoselective photochromism. Change in CD spectra, on/off switching of fluorescence, and reversible change in pitch length of induced cholesteric liquid crystalline phase, were observed.

ISSN:1058-725X    

DOI:10.1080/10587250008023840

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Some novel heterobenzopyrans have been synthesised and their photochromic properties are discussed.

ISSN:1058-725X    

DOI:10.1080/10587250008023841

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Palladium-catalyzed carbonylation of substituted 2-butyne-1,4-diols affords a variety of photochromic fulgides in one step. This methodology provides an alternative to the traditional method based on the Stobbe condensation.

ISSN:1058-725X    

DOI:10.1080/10587250008023842

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Oxazolyl fulgide withp-dimethylaniline group (fulgide1) revealed favorable absorption spectra, high photochromic responses and high thermostabilities in a polystyrene or a poly(methyl methacrylate) film spin-coated on a silica glass, but it suffered from extensive photochemical fatigues while phenyl-substituted oxazolyl fulgide (fulgide2) revealed much less fatigues. The photochemical fatigues of fulgide1could be substantially suppressed by a simple treatment of the spin-coated films to keep air-tight. Similar improvement in the photochemical fatigue resistance was obtained with films of the well-known furylfulgide. Further, thermal stabilities were significantly improved towards heating at 80°C. These effects are ascribable to the effective shielding of the air (molecular oxygen).

ISSN:1058-725X    

DOI:10.1080/10587250008023843

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The synthesis of a series of 2-ferrocenyl-2-methyl-[2H]-benzopyranes and the results of a spectrokinetic study are presented. A broadening of the absorption band in the visible range and the apparition of a second absorption band is observed as compared with the reference compounds. Furthermore important kinetic modifications are observed. From these results a structure can be proposed for a permanent opened form which is observed in polar protic solvents.

ISSN:1058-725X    

DOI:10.1080/10587250008023844

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Four heliochromic benzothienylfulgides were synthesized and their spectral properties, photochromism, and the decoloration kinetics were examined. Photocyclization of E-form occurred on the benzothiophene ring but not on the phenyl ring for4and5. Introduction of an isopropyl group (3) or a phenyl group (4, 5) on the benzothienylmethylidene group retarded the decoloration rate of O-forms. Introduction of a phenyl group (4, 5) also resulted in 40-nm red-shift of absorption and three-fold increase in molar absorption coefficients of O-forms in the visible region.

ISSN:1058-725X    

DOI:10.1080/10587250008023845

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The synthesis of a series of dimethyl 6-aryl-2,2-dimethyl-[2H]-chromene-7,8-dicarboxylates is described. The photochromic properties of this new family of dimethyl-[2H]-chromenes have been studied in solution, under continuous irradiation. The presence of the methoxycarbonyl groups was shown to stabilise the coloured forms. The fading rates are generally low in comparison with the standard “naked” chromenes in the same experimental conditions. This stabilisation depends on the solvent used. We could observe the presence of one permanent opened form. Moreover, it seems that the synthesised molecules have a strong resistance toward photodegradation.

ISSN:1058-725X    

DOI:10.1080/10587250008023846

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor