Photochromic Properties of Pyrryl Fulgides

We evaluated the photochromic properties of pyrryl fulgides by means of comparing their quantum yields of photocoloring, thermal stabilities and fatigue resistances.     

光致变色WO3/4,4'-BPPOBp超晶格薄膜的制备

具有光致变色和电致变色特性的三氧化钨薄膜因其巨大的应用前景而倍受人们关注[1-4].其制备方法一般为物理沉积方法和化学沉积方法等.其中化学方法包括喷射裂解法[5],化学气相沉积法[6,7],电化学沉积法[8]和溶胶凝胶法[9]等.利用超分子化学自组装技术构建用有机组分调控的光致变色纳米超晶格薄膜材料,是研制光致变色功能薄膜材料的新方法.本文采用溶液中相反电荷聚电解质超分子自组装的方法(ＰＥｓ法)[10],制备了ＷＯ3/4,4′ＢＰＰＯＢｐ超晶格薄膜.采用紫外可见吸收光谱和小角Ｘ射线衍射谱对薄膜的结构和分子的排列方式进行了研究.1　实验…     

A Series of Polyoxometalate-Viologen Photochromic Materials for UV Probing,Amine Detecting and Inkless and Erasable Printing

In this work, by using two kinds of viologen ligands three POM-based Compounds were obtained under hydrothermal conditions, namely [Ag^I(bmypd)_0.5(β-Mo₈O₂₆)_0.5] (1) (bmypd ⋅ 2Cl=1,1′-[Biphenyl-4,4′-bis(methylene)]bis(4,4′-bipyridyinium)dichloride), [Ag^I₂(bypy)₄(HSiW₁₂O₄₀)₂] ⋅ 14H₂O (2) and [Ag^I(bypy)(γ-Mo₈O₂₆)_0.5] (3) (bypy⋅Cl=1-Benzyl-4,4′-bipyridyinium chloride). The structures were characterized by Fourier transform infrared spectroscopy (FT–IR), Powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS) and single crystal X-ray diffraction. Compounds 1–3 show excellent photochromic ability with fast photoresponse under the irradiation of ultraviolet light with different degrees of color changes. So compounds 1–3 can be used as visible ultraviolet detectors. Compounds 1–3 also possess photoluminescence properties with fast and excellent fluorescence quenching effect. Compounds 1–3 also can be used as inkless and erasable printing materials with suspensions of 1–3 applied to filter paper. Compounds 1–3 can also produce color changes in amine vapor environment, especially in an NH₃ atmosphere. Compounds 1–3 can be used as organic amine detectors.     

Synthesis and properties of 1,3,3-trimethylspiro[indoline-2,3′-naphtho[2,1-b][1,4]oxazin]-6′-amine, a novel, red colouring photochromic spirooxazine

The synthesis and photochromic properties of 1,3,3-trimethylspiro[indoline-2,3′-naphtho[2,1-b][1,4]oxazin]-6′-amine, a novel red-colouring photochromic spirooxazine and derivatives is reported. The synthesis proceeds via an unusual one-pot transamination, oxime formation, N-O bond cleavage, spirooxazine formation process.     

通过构象诱导电感耦合机制光可逆调控有机场效应晶体管的性能

将有机场效应晶体管用于传感和开关实际应用的主要阻碍之一是其破坏性传感机制产生的一系列问题. 这里我们报道了一种智能的系统, 用光致变色分子螺吡喃(SP)和聚甲基丙烯酸甲酯(PMMA)结合作为栅介电材料, 得到的器件能以一种无损的方式, 通过光可逆调控器件的导电性能. 当螺吡喃分子发生可逆的光学异构时, 器件的电容和导电性随之发生显著而可逆的变化. 这种构象诱导电感耦合的作用机理提供了一种制备功能器件的新方法, 可以推广为利用其它刺激响应型分子来制备特定功能器件的普适性方法.     

Laser photochromic dye activation technique for the measurement of liquid free surface velocity on curved surfaces

An optical method is presented which permits the determination of the free surface velocity of liquid films flowing on curved surfaces. The feasibility of this technique, which involves the laser tomography and photochromic dye activation techniques, is demonstrated on an oil film flowing around a finned tube. Results for different tube geometries and flow conditions are presented. Advantages and limits of the laser photochromic velocimetry technique are discussed.     

Photoinduced chirality in a photochromic stilbene-molecule-doped polymeric liquid crystal film

Photoinduced chirality has been demonstrated in thin films of a main-chain polymeric liquid crystal (PLC) system doped with photochromic stilbene molecules by irradiation with circularly polarized light (CPL). CPL-induced chirality was observed in the intrinsically achiral films which were doped with low-molecular-weight stilbene molecules. It was found that the level of photoinduced chirality of the stilbene-molecule-doped system is comparable to that of the azobenzene-molecule-doped system. Moreover, reversible photo-rewriting property for the stilbene-doped system was also demonstrated by alternating irradiation with right- and left-CPL.     

Synthesis and characterisation of photochromic dithienylcyclopentene liquid crystal with thermal irreversibility

A series of photochromic liquid crystal dithienylcyclopentene derivatives were synthesised from the initial material 2-chloro-5-methylthiophene. They were characterised by ¹H NMR, high resolution mass spectrometer, differential scanning calorimetry (DSC) and polarised optical microscopy (POM) with a hot stage. All of them exhibited excellent photochemically reversible isomerisation between the open-ring form and the closed-ring form in both organic solvents and LC media, resulting in the colour change between colourless and purple under different light irradiations. The typical textures from POM showed that their isomers both had nematic phase and smectic phase with different colours. These compounds with bent shape were more sensitive to light than those of diarylethenes reported.     

The helical structure of a photochromic spironaphthopyran

The title compound, 6′-ethoxycarbonylspiro(indoline-2,2′-[2H-1]-naphthopyran) (Compound I), was synthesized and the structure was determined by X-ray diffraction. Introduction of an ethoxycarbonyl group in the 6′-position of the indoline moiety affects the whole arrangement of molecular self-assembly. The carbonyl oxygen atom is involved in hydrogen bond, through which the stacking arrangement in the crystal forms a helical structure.     

1,2-二甲基-3-吲哚甲叉(异丙叉)丁二酸酐(1)和1,2-二甲基-3-吲哚乙叉(异丙叉)丁二酸酐(2)的晶体结构

1.2-二甲基-3-吲哚甲叉(异丙叉)丁二酸酐(1)(C_(18)H_(17)NO_3)与1.2-二甲基-3-吲哚乙叉(异丙叉)丁二酸酐(2)(C_(19)H_(19)NO_3)同属于吲哚俘精酸类化合物,它们的分子结构非常类似,只是(1)中为吲哚甲叉,(2)中为吲哚乙叉.但它们的光色性却差别很大.化合物(1)无光致变色性,化合物(2)则表现为良好的光致变色性.其原因在于结构的不同。