1,2-二芳基乙烯分子无损读取研究

1,2-二芳基乙烯类光致变色分子具有优良的热稳定性和耐疲劳性.它们作为新一代的光存储材料以及分子器件中光电微观性质控制的分子开关,引起了人们的重视.本文介绍了1,2-二芳基乙烯类光致变色分子的合成方法和光致变色性质,重点综述了这类分子在无损读取光存储材料方面的研究进展.     

新型二芳基乙烯光致变色化合物的制备及其应用基础研究

<正>二芳基乙烯光致变色化合物在存储、显示、开关、防护、防伪及化学传感器等方面具有潜在的应用价值.本论文设计合成了一系列分别以2,5-二氢噻吩和咪唑为桥头的新型二芳基乙烯光致变色化合物,研究了该类化合物的光致变色性质,并探索了它们在光存储、光开关和化学传感器等方面的应用.     

二芳基乙烯类化合物用作光开关的最新研究

本文在综述二芳基乙烯类化合物各种性能的基础上,重点介绍了二芳基乙烯类化合物作为荧光光控开关、荧光共振能量转移、光致变色电开关、光致变色磁开关、光致变色液晶开关和多功能光致变色开关的最新发展动态,以及二芳基乙烯类化合物的形态对光开关性能的影响。最后对未来光存储材料的研究趋势作了展望。     

新型烯桥二芳基乙烯光致变色体系

光致变色材料在一定的波长和强度的光作用下分子结构发生开闭环等变化,从而导致其对光的吸收峰（即颜色）的相应改变,且这种改变一般是可逆的。光致变色体系在光照前后的物理、化学性能（特别是吸收、荧光性质）会发生显著变化,可广泛应用于变色眼镜、光开关、逻辑门以及信息存储等领域。在众多光致变色体系中,有机二芳基乙烯体系具有高热稳定性,一直是应用研究的热门对象。由于全氟环戊烯作为烯桥具有突出的抗疲劳度、双稳态性能,目前大多数二芳基乙烯皆基于此烯桥而设计制备。鉴于二芳基乙烯的烯桥处于光反应中心,对光致变色性能调控尤为显著,而全氟环戊烯作为烯桥在结构上惰性而难以实现化学修饰,因而近年来涌现出许多新型的桥连,实现了更好的性能和更多的应用,本文介绍具有代表性的烯桥及其对应的二芳基乙烯化合物的研究现状,并对其应用前景进行了分析及展望。     

1,3,4-噁二唑键联二芳基乙烯化合物的合成及性质

将1,3,4-噁二唑基团引入二芳基乙烯分子中, 合成了2种新的二芳基乙烯类光致变色化合物1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯(3)和1,4-二{[1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯]-1,3,4-噁二唑}苯(4). 通过IR, NMR, MS和元素分析对化合物进行了结构表征, 并研究了其UV-Vis吸收、荧光发射、动力学特性和抗疲劳性质. 实验结果表明, 化合物[STHZ]3[STBZ]和[STHZ]4[STBZ]具有良好的光致变色性质, 光致变色闭环反应为零级反应, 开环反应为一级反应.     

光致变色全氟环戊烯类二芳烯化合物的合成及其性质研究

合成了两种新的二芳基乙烯类光致变色化合物1,2 双(2 甲基5 (4 乙氧基苯基)噻吩3 基)全氟环戊烯(1a)和1,2 双(2 甲基5 (对氟苯基)噻吩3 基)全氟环戊烯(2a),并且研究了其在不同溶剂和浓度中的UV Vis光谱、荧光性质和光致变色反应动力学特征.实验结果表明,化合物1a和2a具有良好的光致变色性质和较强的荧光;光致变色闭环反应为零级反应,开环反应为一级反应.     

一种新型二氰基乙烯修饰的二呋喃环戊烯光开关:荧光性质、传感性能和生物应用（英文）

近年来,借助于高度优化的小分子荧光染料,荧光蛋白和先进的标记技术,荧光标记技术得到了极大的发展.二芳基乙烯光开关荧光染料的研究,主要通过在二芳基乙烯中引入荧光核和对芳基的结构修饰.与噻吩相比,呋喃具有更好的刚性、溶解性和可生物降解能力以及更强的荧光.因此,二呋喃乙烯可以作为荧光标记技术的小分子荧光染料.设计并制备了一种基于二氰基乙烯的二呋喃乙烯新型荧光光开关.该化合物在溶液中呈现典型的可逆光致变色性能,且以其出色的选择性、灵敏度和高对比度来实现氰根离子的荧光检测.此外,通过核磁滴定实验,解释了其对氰根离子的响应机理.由于采用呋喃替换噻吩使得该化合物拥有更强的荧光,成功应用于生物体内的荧光染料和氰根离子探针.     

光致变色聚合物研究进展

本文主要介绍了9类光致变色聚合物的研究状况,包括光致变色螺吡喃聚合物、螺噁嗪聚合物、二芳基乙烯光致变色聚合物、偶氮苯类光致变色聚合物、苯氧基萘并萘醌光致变色聚合物、俘精酰亚胺光致变色共聚物、硫靛光致变色共聚物、双硫腙光致变色聚合物以及二氢吲嗪光致变色聚合物等.讨论了聚合物的合成、光致变色性质、影响聚合物性质的因素,并对光致变色聚合物未来的研究重点和方向作了展望.     

六芳基二咪唑类化合物的合成及光致变色性能

六芳基咪唑;六芳基二咪唑类化合物的合成及光致变色性能     

α-氨基酸酯/α-氨基腈与芳香硼酸的脱氨偶联反应合成α-芳基酸酯/α-芳基腈

正α-芳基酸衍生物和α-芳基腈类有机化合物具有潜在的生理、药理活性,并且作为重要的结构骨架存在于各种天然产物和药物中.同时,由于其官能团转化的多样性,也是众多精细化学品的中间体.因此,这类化合物备受人们关注,其合成方法也是研究的热点.由Buchwald,Hartwig等发展的钯催化的酯、腈的α-芳基化需要使用强碱,较昂贵     

Post‐Modification of the Ethene Bridge in the Rational Design of Photochromic Diarylethenes

Fine‐tuning of the molecular structure of organic bistable compounds to improve their photochromic performance or to introduce additional functions remains an important issue in the development of photoresponsive materials. Diarylethenes bearing heterocyclic moieties belong to the most intensively studied class of organic photochromes due to their excellent photochemical properties. A huge number of diarylethenes have been synthesized so far. Analysis of the literature data shows that there are very worthy examples of diarylethenes developed by the Irie and Feringa groups, which can be the common starting material for a number of diarylethenes functionalized in hetaryl moieties. We refer to these structures as photochromic diarylethene precursors. These diarylethenes have proved to be very useful in the construction of functional molecules with desired properties. On the other hand, in our groups, we have elaborated on diarylethene precursors with modifiable ethene bridges. In this review, we have collected examples of such structures and their chemical modifications, leading to the improvement or fine‐tuning of photochromic switching.     

Electrical properties of photochromic organic systems (review)

The results of studying the electrical properties of organic photochromic systems based on diarylethenes, spiropyrans, spirooxazines, and azo compounds have been analyzed. It has been shown that diarylethenes have promise for use in photoswitches of various types that reversibly and simultaneously change the spectral and electrical properties when exposed to light.     

Efficient One‐step Synthesis and Properties of Photochromic Diarylethenes Having an Indene Bridging Unit

Two novel isomeric photochromic diarylethenes with an indene bridging unit have been prepared by a simple and efficient one‐step synthesis method. Their properties, including photochromic behavior, fluorescent properties and fatigue resistance, have been investigated. These two isomeric compounds showed photochromic back‐and‐forth reactions with ultraviolet and visible light both in solution and in PMMA film. Their ring‐open forms exhibited appreciable fluorescence, which was quenched by the ring‐closed forms. All results indicated that diarylethenes derivatives with indene‐aryl bridges exhibited rather high fatigue resistance and good thermally irreversible photochromic properties.     

光控二芳烯化学传感器及其研究进展

有机光致变色材料由于在光学记忆及分子开关器件等领域具有潜在的应用价值而备受关注。在众多有机光致变色系统中,二芳烯类光致变色化合物具有热稳定性好、耐疲劳、响应速度快和灵敏度高等优点,在光电材料和生物医学领域具有广阔的应用前景。近年来,围绕二芳烯构建可调控光化学传感器已成为功能材料领域的一大研究热点。本文主要介绍以二芳烯作为光调控单元合成具有多重调控功能的化学传感器的研究进展,并展望了该领域的应用前景和研究方向。     

Efficient synthesis and properties of isomeric photochromic diarylethenes having a pyrrole unit

Two new isomeric photochromic diarylethenes with a pyrrole unit have been developed. Their properties, including photochromic behavior, crystal structures, and fluorescent properties, have been investigated. The two isomeric compounds show distinctly different photochromism, both in solution and in the single-crystalline phase: one turns red upon photocyclization whereas the other turns blue, which may be attributed to the different substituent effects.     

Modulation of the refractive index by photoisomerization of diarylethenes: theoretical modeling

Molecular polarizabilities of photochromic diarylethenes bearing different chemical groups as substituents have been calculated by density functional theory (DFT) simulations with the aim to obtain an estimate of the refractive index of a glassy matrix containing diarylethenes as active species. Simple models have been introduced in order to take into account the effects that occur in bulk materials. The results obtained show that the choice of suitable substituents enhances the modulation of the refractive index driven by the photochromic reaction; moreover, the trends predicted are consistent with the experimental data. This opens the way to use quantum chemical predictions on model molecules to foresee performances relative to the photoinduced modulation of the refractive index in bulk materials.     

Design of mesomorphic diarylethene-based photochromes

The effects of the molecular variation of diarylethenes on the mesomorphic, photochromic, and fluorescence properties have been investigated, and dramatic changes in the fluorescence, photochromic, and liquid crystal behavior were observed.     

Study on photochromism of diarylethenes with a 2,5-dihydropyrrole bridging unit: a convenient preparation of 3,4-diarylpyrroles from 3,4-diaryl-2,5-dihydropyrroles

Symmetric and nonsymmetric diarylethenes with a 2,5-dihydropyrrole bridging unit have been prepared, and the photochromic properties are investigated. Both symmetric and nonsymmetric diarylethenes with 2,5-dihydropyrrole bridging units undergo reversible ring-opening and ring-closing photoisomerization reactions in nonpolar solvents with UV/vis light, and some of them exhibit good fatigue resistance and no marked degradation detected after 10 cycles via an on/off switch. In polar solvents, however, photochromic diarylethenes with 2,5-dihydropyrrole bridging units produce 3,4-diarylpyrrole derivatives instead of the ring-closing isomer of diarylethenes with UV light irradiation. A class of N-substituted 3,4-diphenylethenes with 2,5-dihydropyrrole bridging units were prepared and used as templates to investigate the conversion reactions. The mechanism of photoconversion of 3,4-diaryl-2,5-dihydropyrroles to 3,4-diarylpyrroles was explored as well.     

New thermally stable photochromic di(het)arylethenes of the cyclopentenone series

Oxidation of 2,3-diarylcyclopent-2-en-1-ones with m-chloroperoxybenzoic acid gave new thermally stable sulfone derivatives of photochromic diarylethenes. The spectral properties of the compounds obtained (the wavelengths of the maxima of the absorption bands of their initial and cyclic forms, the quantum yields of photocyclization and photobleaching reactions) as well as their thermal stability and fatigue resistance were examined. The relationship between the structures of the synthesized compounds and their photochromic properties was determined. The energy differences between the ground-state molecules of the starting and photoinduced isomers of 2,3-diarylcyclopent-2-en-1-ones were calculated by the DFT/B3LYP1 method with the 6-31G(d) basis set. The calculated energy differences can be used to predict and explain such spectral characteristics of photochromic diarylethenes as the thermal stability of photoinduced isomers and the quantum yields of cycloreversion reactions.