多钼酸盐–柠檬酸复合膜的多色光致变色

制备了多钼酸盐–柠檬酸光致变色复合膜，紫外光照后发现不同摩尔比的复合膜呈现不同的颜色。当摩尔比为1.0，0.3和0.2时，变色后的薄膜分别显深蓝色，深黄褐色和淡海绿色。通过对薄膜的拉曼光谱分析证实呈现不同的颜色是由于在变色后的膜中生成了不同的物种。柠檬酸在光致变色过程中起着重要的作用, 在紫外光的照射下它作为空穴的捕获剂, 抑制了光生电子和空穴的复合, 使多钼酸盐呈现紫外光致变色现象。     

Room-Temperature Phosphorescence Invoked Through Norbornyl-Driven Intermolecular Interaction Intensification with Anomalous Reversible Solid-State Photochromism

Herein, norbornyl (NB), a bulky annular nonconjugated spacer, is melded into π systems to construct two groups of ladder-type room-temperature phosphorescence (RTP) luminogens. The effect of the NB on π-π interactions, packing modes and RTP performance is explored systematically. The experimental and computational results demonstrate the versatility of NB in reducing π-π distances and synergistically intensifying the intermolecular interactions, which not only induces intersystem crossing from S₁ to T_n but also diminishes the nonradiative decay of triplet excitons. Impressively, 1800-fold phosphorescence lifetime enhancement is achieved in comparison with the reference compounds without NB. The molecular packing and RTP performance can be further modulated by the length of the backbones and terminal end-groups. It is quite peculiar that NB-annulated phthalic acid exhibits reversible photochromism in the solid state, likely due to the formation of persistent radical pairs. Our study paves an ingenious avenue towards enhancing intermolecular interactions and provides significant implications for a better comprehensive understanding of the origin of their RTP and the inherent photophysical mechanism.     

萘氧基萘并萘醌的合成和光致变色性质

萘氧基萘并萘醌的合成和光致变色性质方政，杨志范，王淑芝，徐素贤，方天如，王佛松（吉林工学院化工系长春）（中国科学院长春应用化学研究所长春１３００２２）关键词萘氧基萘并萘醌，合成，光致变色苯氧基萘并萘醌类光致变色材料具有耐疲劳，室温下几乎无热消失反应，...     

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     

苯氧基萘并萘醌衍生物的合成与光致变色性能研究

设计合成了16个新的具有不同迁移基团、不同取代基及双苯氧基萘的苯氧基并萘醌化合物; 通过红外光谱、核磁共振、质谱等方法对其结构进行了表征; 利用紫外-可见光谱研究化合物的光致变色性, 结果表明, 化合物的结构影响其变色性能, 当迁移基团为芳香基时, 其变色性较好; 主链醌环上有取代基时, 化合物成色体最大吸收波长红移; 双苯氧基萘并萘醌化合物较相应的单化合物有较大的摩尔吸光系数; 随着苯基上取代基增大, 其成色速率常数变小.     

光致变色与光子器件

本文概述了光致变色和光子器件领域的发展现状和机遇。总结了他们在基础和应用方面获得的结果。通过激光光解技术、时问分辨光谱和反应中问体的衰减动力学深入研究了光致变色机理。     

萘并吡喃类固态光致变色化合物的合成及性能研究

合成了化合物 ２,２－二芳基萘并吡喃（２ａ－２ｐ）,产物结构和组成通过１Ｈ ＮＭＲ, ＭＳ和元素分析证实．测定了化合物光照前后的紫外可见吸收光谱．部分化合物表现出良好的固态光致变色性能,分析了它们的结构与光致变色性能间的关系．     

Multistate Photoswitches: Macrocyclic Dihydroazulene/Azobenzene Conjugates

Molecules comprised of three covalently linked bi‐stable switches can exist in states described by a combination of binary numbers, one for each individual switch: ?000?, ?001?, etc. Here we have linked three photo‐/thermoswitches together in a rigid macrocyclic structure, one azobenzene (bit no 1) and two dihydroazulenes (DHAs; bits no 2 and 3) and demonstrate how electronic interactions and unfavorable strain in some states can be used to control the speed by which a certain state is reached. More specifically, upon irradiation of state ?000?, the AZB isomerizes from trans to cis and the two DHAs to vinylheptafulvenes (VHFs), generating ?111?. The thermal VHF‐to‐DHA back‐reactions from this state also occur stepwise and can be accelerated by photo‐induced AZB cis‐to‐trans conversion, proceeding via ?011? to ultimately furnish ?000?. Overall, the accessibility to a specific state of one bit was found to depend on the states of its neighboring bits.     

Photochromism and the spectral properties of bispiroanthro-bis-oxazine

The spectral and photochromic properties of bispiroanthro-bis-oxazine (bis-SAO) in toluene, DMF, and polystyrene films were investigated in the 77–300 K interval. It is shown that the long-wave part of the absorption spectrum of the starting form of the molecule is formed by three-electron transitions localized in the anthro-bis-oxazine fragment. The directions of the oscillators of these transitions relative to the nuclear. backbone of the molecule are proposed on the basis of luminescence polarization data. It is proposed that the photochromic properties of the solutions are determined by the existence of bis-SAO molecules in dimer form.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Institute of Solid State and Semiconductor Physics, Academy of Sciences of Belarus, 210023 Vitebsk. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2718–2725, December, 1992.     

Arylazo-3,5-dimethylisoxazoles: Azoheteroarene Photoswitches Exhibiting High Z-Isomer Stability,Solid-State Photochromism,and Reversible Light-Induced Phase Transition

Reversibly photoswitchable phenylazo-3,5-dimethylisoxazole and 37 aryl-substituted derivatives were synthesized. Excellent photoswitching ability of these compounds in solution and the solid state was demonstrated. Through kinetics studies by means of NMR spectroscopy, high Z-isomer stability was demonstrated. Interestingly, the majority of the derivatives showed light-induced contrasting color changes in solution and the solid state. Besides, many of the derivatives exhibit partial phase transition upon UV irradiation. The highlight of this class of photoswitches is the reversible light-induced phase transition between solid and liquid phases in the parent compound, which can be used in patterned crystallization. These results show that this new class of azoheteroarene based photoswitches has opportunities to be useful in various domains.     

Controlling Two‐Step Multimode Switching of Dihydroazulene Photoswitches

We present the synthesis and switching studies of systems with two photochromic dihydroazulene (DHA) units connected by a phenylene bridge at either para or meta positions, which correspond to a linear or cross‐conjugated pathway between the photochromes. According to UV/Vis absorption and NMR spectroscopic measurements, the meta‐phenylene‐bridged DHA–DHA exhibited sequential light‐induced ring openings of the two DHA units to their corresponding vinylheptafulvenes (VHFs). Initially, the VHF–DHA species was generated, and, ultimately, after continued irradiation, the VHF–VHF species. Studies in different solvents and quantum chemical calculations indicate that the excitation of DHA–VHF is no longer a local DHA excitation but a charge‐transfer transition that involves the neighboring VHF unit. For the linearly conjugated para‐phenylene‐bridged dimer, electronic communication between the two units is so efficient that the photoactivity is reduced for both the DHA–DHA and DHA–VHF species, and DHA–DHA, DHA–VHF, and VHF–VHF were all present during irradiation. In all, by changing the bridging unit, we can control the degree of stepwise photoswitching.     

2-芳氧基-1,8-邻苯二甲酰基萘的合成及光致变色性

合成了3种2-芳氧基-1,8-邻苯二甲酰基萘类光致变色化合物,通过核磁共振谱、红外光谱、质谱和元素分析确定了结构.对产物进行了荧光光谱测定,3种光致变色化合物的荧光强度和Stoke位移都较大.用紫外-可见分光光度计对其在丙酮溶液中的光致变色行为进行了测定,3种光致变色化合物在300-600 nm范围内都具有一定的光致变色性能和较大的吸光系数.     

Multistate Switches: Ruthenium Alkynyl–Dihydroazulene/Vinylheptafulvene Conjugates

Multimode molecular switches incorporating distinct and independently addressable functional components have potential applications as advanced switches and logic gates for molecular electronics and memory storage devices. Herein, we describe the synthesis and characterization of four switches based on the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermoswitch pair functionalized with the ruthenium‐based Cp*(dppe)Ru ([Ru*]) metal complex (dppe=1,2‐bis(diphenylphosphino)ethane; Cp*=pentamethylcyclopentadienyl). The [Ru*]–DHA conjugates can potentially exist in six different states accessible by alternation between DHA/VHF, Ru^II/Ru^III, and alkynyl/vinylidene, which can be individually stimulated by using light/heat, oxidation/reduction, and acid/base. Access to the full range of states was found to be strongly dependent on the electronic communication between the metal center and the organic photoswitch in these [Ru*]–DHA conjugates. Detailed electrochemical, spectroscopic (UV/Vis, IR, NMR), and X‐ray crystallographic studies indeed reveal significant electronic interactions between the two moieties. When in direct conjugation, the ruthenium metal center was found to quench the photochemical ring‐opening of DHA, which in one case could be restored by protonation or oxidation, allowing conversion to the VHF state.     

萘并萘醌酚醛树脂的合成和光致变色性质

通过6-氯-5,12-萘并萘醌(1)与酚醛树脂经亲棱取代,一步合成制备具有光致变色性的酚醛树脂(3)。在苯溶液中,光致变色聚合物(3)与光致变色化合物6-{4-[2-(4-羟基苯基)异丙基]苯氧基}-5,12-萘并萘醌(2)有相似的光致变色行为。但是,在聚合物(3)中,由于苯基处于聚合物骨架中不易迁移,使聚合物(3)的变色速度较化合物(2)明显减慢,化合物(2)的光异构化速度常数是聚合物(3)的3倍。同时发现溶剂对聚合物(3)的光诱导trans-ana异构化反应速度有明显影响,在氯仿中的反应速度常数约为在苯中的2倍。     

侧基含偶氮苯生色团的短梗霉多糖的制备及光致变色性

利用4-(4-硝基苯偶氮)-1-萘酚的丙烯酸酯与短梗霉多糖进行接枝共聚,制备了侧基含偶氮苯生色团的短梗霉多糖聚合物,并用红外光谱、扫描电镜、X射线衍射、热重分析等手段对聚合物进行了表征.用紫外光谱研究了聚合物的光致变色性,结果表明聚合物具有良好的热稳定性和光致变色性.     

Light-Driven Reversible Multicolor Supramolecular Shuttle

Light-driven multicolor supramolecular systems mainly rely on the doping of dyes or a photo-reaction to produce unidirectional luminescence. Herein, we use visible light to drive the bidirectional reversible multicolor supramolecular shuttle from blue to green, white, yellow, up to orange by simple encapsulation of spiropyran-modified cyanostilbene (BCNMC) by the macrocyclic cucurbit[8]uril (CB[8]) monomer. The resultant host–guest complex displayed enhanced fluorescence properties, i.e. the multicolor fluorescence shuttle changed from blue to orange in the dark within 2 hours and reverted to the original state upon visible light irradiation for 30 s. Benefiting from the sensitivity of the spiropyran moiety to light, it can spontaneously isomerize from the ring-opened state to a ring-closed isomer in aqueous solution, and this photo-isomerization reaction is a reversible process under visible light irradiation, leading to the multicolor luminescence supramolecular shuttle as a result of intramolecular energy transfer. In addition, the light also drove the reversible conversion of the topological morphology of the host–guest complex from two-dimensional nanoplatelets to nanospheres. Different from the widely reported molecular rotaxane “shuttle”, the spiropyran supramolecular shuttle confined in the macrocyclic host CB[8] not only modulated a reversible topological morphology by light but also exhibited multicolor luminescence, which was successfully applied in programmed and rewritable information encryption.     

柠檬酸铁（Ⅲ）络合物的光致变色现象与柠檬酸的测定

报道了柠檬酸铁（Ⅲ）络合物的光致变色现象并将其应用于微量柠檬酸（或盐）的测定。在ＰＨ１．８－２．５的酸性介质中，柠檬酸与Ｆｅ＾３＋生成的黄色络合物在光照下发生光致变色生成紫色络合物，其最大吸收波长为４９０ｎｍ；表观摩匀吸光系数ε为８０５Ｌｍ．ｍｏｌ＾－１．ｃｍ＾－１，络合物的组成比为１：１。方法的线性范围为０－－２５０ｍｇ／Ｌ，用此法测定了几种饮料的中的柠檬含量，结果令人满意。     

磷钨酸-PVA复合体系膜的制备和光色性研究

用旋转涂布法制得了PVA -H3PW1 2 O40 复合体系的光敏膜。研究了膜对光的响应情况 ,发现复合体系对光的响应情况与体系内各成份的浓度无关。光敏性的产生源于体系内PVA的 OH与钨磷酸阴离子中Oc的相互作用。     

3-甲基-1,4-二苯氧基-9,10-蒽醌的合成及其光致变色性

合成了3-甲基-1,4-二苯氧基-9,10-蒽醌,其结构经1^H NMR,13^C NMR,IR和MS表征,并通过紫外光谱探讨了其光致变色性,讨论了取代基对蒽醌类化合物光致变色性的影响。