荧光分子开关的研究进展

荧光分子开关是超分子化学领域的研究热点之一,本文根据开关动作完成的方式对近年来研究的各类荧光分子开关进行了简要的归类总结,并介绍了一些具有特殊功能的荧光分子开关器件．     

富勒烯(C60)衍生物分子器件的研究与应用

介绍了富勒烯衍生物分子器件在分子导线,分子开关和分子储存器的研究进展,展望了分子器件发展前景。     

2,4‘—甲酰基苯乙烯基苯并噻唑衍生物的合成和光谱特性

氮杂芪（ａｚａｓｔｉｌｂｅｎｅ）衍生物及其盐类,是一类重要的功能化合物,和普通的芪类化合物相比,它的光谱响应范围可以大幅度地移向长波区．同时它具有很强的分子可极化率,对外场作用响应灵敏．因此,它在非线性光学［１］、溶致变色［２］、固定酶［３］和光刻胶...     

氧鎓盐分子在受限制体系中的电荷转移和发光行为

氧盐分子在受限制体系中的电荷转移和发光行为陈懿汪鹏飞吴世康（中国科学院感光化学研究所，北京１００１０１）关键词氧盐，分子内电荷转移，分子内能量转移，受限制体系，光物理性质２，４，６三芳基氧盐是一类类似于三苯甲烷染料的化合物［１］．其结构...     

4－［2－（9，10－二氰基蒽）乙烯基］－N，N－二甲基苯胺的三荧光发射

４－［２－（９，１０－二氰基蒽）乙烯基］－Ｎ，Ｎ－二甲基苯胺的三荧光发射王华，陈景荣，张宝文，曹怡（中国科学院感光化学研究所光化学开放实验室，北京１００１０１）关键词分子内电荷转移，荧光发射从分子水平进行电子转移，电荷分离的研究是十分重要的，它不仅是...     

有机荧光分子在信息化学方面的应用

有机荧光分子可作为分子开关、可构建分子逻辑门、具有信息存储等功能在信息化学领域中有着广泛的应用前景。介绍了分子逻辑门及分子开关概念的基础上，有机荧光分子开关分三类（化学控制的荧光分子开关、氧化还原反应控制的荧光分子开关、光控制的荧光分子开关），综述了所构建的逻辑门在信息化学方面应用。     

识别中性分子客体荧光传感和开关的研究进展

分子识别是超分子化学的核心概念，而荧光开关PET(photo-induced electron transfer)体系又是分子识别中的重要组成部分，是超分子化学和光物理学科相结合的成就。本文总结了近年来对中性客体分子的荧光传感和开关的研究进展。     

卟啉衍生物的应用

卟啉衍生物的应用彭波（中国船舶工业总公司西安东风仪表厂，７１００６５）自然界的卟啉衍生物主要是叶绿素和血红素［１］，叶绿素是光合作用中心的关键分子。卟啉衍生物与蛋白质结合构成的血红蛋白、肌红蛋白和细胞色素等具有氧的输送、贮存及电子传递功能。由于卟啉衍...     

吡唑啉衍生物作为空穴传输层在电致发光材料中的应用

我们曾报道过有关１，３二苯基吡唑啉衍生物的光谱和光物理行为［１，２］，并详细地研究了它们在受激发后的辐射和非辐射衰变过程．该类化合物作为一种良好的光致发光材料，由于存在着分子内共轭的电荷转移结构，因此表现出较强的光诱导分子极化能力，可用作为有机非线性光学材料［３］、光折变材料等．此外，还发现该类化合物在组合型光导器件中可用作空穴传输层材料．既然这类化合物兼具光致发光和空穴传输功能，很自然的会考虑到，它是否也能用作为一种有机的电致发光（ＥＬ）材料．有机电致发光材料的重要性自不待言，特别近年来许多…     

有机物在离子液体中无限稀释活度因子及液液界面张力的定量机构-性质关系

用PM3半经验量子化学方法计算了烷烃、烯烃和芳烃等的疏水性参数lgP、偶极矩、前线分子轨道能隙和水合能等结构描述符,与实验测定的烃类在1-丁基-3-甲基咪唑六氟磷酸盐（［C₄MIM］［PF₆］）、1-烯丙基-3-甲基咪唑四氟硼酸盐（［AMIM］［BF₄］）、1-异丁烯基-3-甲基咪唑四氟硼酸盐（［MPMIM］［BF₄］）和［MPMIM］［BF₄］-AgBF₄ 4种离子液体中的无限稀释活度因子进行定量结构-性质关系（QSPR）研究,建立的QSPR模型具有良好的关联和预测能力.同时测定了烃类等溶质与离子液体［C₄MIM］［PF₆］的液液界面张力,发现其与无限稀释活度因子有相似的变化趋势,据此采用同样的结构描述符,建立了溶质与［C₄MIM］［PF₆］界面张力的QSPR模型,模型的关联能力良好.     

2,4,5-Triphenyloxazol – Neues Darstellungsverfahren und Eigenschaften bei photoinduzierten Elektronentransfer-Reaktionen

2,4,5-Triphenyloxazole – New Preparative Pathway and Properties in Photoinduced Electron Transfer Reactions The reaction between desylchloride and sodium azide in boiling methanole leads to 2,4,5-triphenyl oxazole (TPO) c in good yields. This new synthetic course can be used for the synthesis of other triaryl substituted oxazoles too. The shortlived excited singlet state of TPO acts as electron donor (towards several types of onium compounds) and as electron acceptor (towards triethanole amine), and is quenched very efficiently. The photo-induced electron transfer reaction with onium salts results in the homolytic decomposition of the neutral radicals of these compounds with moderate quantum yields. All systems investigated can be used as photo-initiators for the free radical polymerization of methyl methacrylate.     

Synthesis and electrochemical properties of intramolecular multi-electron transfer probe compounds

The absorption spectra of diquinone pentacene-5,7,12,14-tetrone (PDQ), have been studied and it was found that the long wavelength absorption of the neutral quinone and of the semiquinone anion radicals were different. For example, λ_max(PDQ) = 375 nm, λ_max(PDQ⁻) = 1350 nm, λ_{max(PDQ²⁻)} = 850 nm. PDQ can be used as an electron acceptor which can accept up to four electrons. Investigations of absorption spectra readily determines how many electrons have been transferred. We have now synthesized a series of compounds containing PDQ as acceptor and carbazole as donor, linked by a chain of variable length.

The intramolecular multi-electron transfer ‘probe’ compounds prepared can be reduced chemically or electrochemically to give the corresponding anion radicals. The reduction potentials for these compounds were estimated by cyclic voltammetry at a mid point between the anodic and cathodic peak potentials. The reduction of the quinones to the semiquinone anion radicals was carried out using 0·1 M tetrabutylammonium tetrafluoroborate in CH₃CN under a N₂ atmosphere.     

不同位置取代的三氰基乙烯基蒽的光谱行为的研究

本文设计合成了两个典型的共轭的电子给体与电子受体化合物：２－三氰基乙烯基蒽与９－三氰基乙烯基蒽，通过极性效应，温度效应对它们基态与激发态的光谱行为进行了表征。研究表明：这两个化全物均表现出显著的电荷转移吸收峰，分子受光激发后，９－ＴＣＶＡ只能在非极性溶剂中产生分子内电荷转移态荧光，而２－ＴＣＶＡ在极性与非极性溶剂中都能从ＩＣＴ态发光。     

Adhesion Between Rubber Compounds Containing Various Adhesion Promoters and Brass-Plated Steel Cords. Part I. Effect of Sulfur Loading in Rubber Compounds

The adhesion property between rubber compounds containing different types of adhesion promoters (resinous adhesion promoter (containing both methylene donor and methylene acceptor), cobalt salt and zinc borate) and different loading amounts of sulfur and brass-plated steel cords was investigated to understand the effect of sulfur loading in the rubber compounds on their adhesion characteristics to the brass-plated steel cords. The adhesion property of the rubber compounds to brass-plated steel cords was largely dependent on both the type of adhesion promoter and the loading amount of sulfur in the rubber compounds. The pull-out force of adhesion samples increased significantly with increasing loading amount of sulfur in the rubber compounds containing resinous adhesion promoter, whereas it decreased slightly with increasing loading amount of sulfur in rubber compounds containing cobalt salt or zinc borate. In humidity aging, the best adhesion retention was observed in the rubber compound containing zinc borate and low loading of sulfur. Regardless of the type of adhesion promoter, adhesion retention after thermal aging treatments improved with increasing loading amount of sulfur in the rubber compounds. The adhesion property was interpreted in terms of the interphases formed between the rubber compounds and the brass-plated steel cords as studied using Auger electron spectroscopy.     

Synthesis,Structural Characterization,Spectroscopic Properties,and Theoretical Investigations of Aminoacridine Derivatives

Synthesis of four N-(heterocyclic)-9-aminoacridine derivatives was investigated. The synthesized compounds, N-thiazolyl-9-aminoacridine (AC1), N-(1,3,4-thiadiazolyl)-9-aminoacridine (AC2), N-(5-methyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC3), and N-(5-phenyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC4) were characterized by FT-IR, ¹H NMR, mass-spectral, and elemental analysis. Amine-imine tautomerism was suggested by density functional theory (DFT) calculations. The optimized structures were obtained using B3LYP/6–311++G(d,p) level of theory. The UV–Vis absorption spectra were measured in various organic solvents. The synthesized compounds AC1–AC4 exhibit absorption spectra characteristic of typical donor–acceptor compounds. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) analysis have been used to explain the internal charge transfer (ICT) phenomena within the molecules. Also, simulated UV spectra were calculated using TD-DFT (B3LYP/6–311++G(d,p) and the results were compared with the experimental values.     

Relationships between hydrogen donor abilities and chemical structure of aromatic compounds in terms of coal liquefaction

To obtain fundamental information about hydrogen transfer, the relationships between hydrogen donor ability and chemical structure of model compounds representing donor solvents is studied using gas chromatography,¹H n.m.r. and computing calculation methods. The order of the model compounds in terms of the ability as donor solvent to release hydrogen is: decalin < tetralin < 1,2-dihydronaphthalene < < 1,4-dihydronaphthalene. This trend closely correlates with the difference in binding energies of the hydroaromatic compounds and their radicals, determined by intermediate neglect of differential overlap (INDO) calculation. Electron spin resonance spectroscopy (e.s.r.) confirms that radical species are created after heat-treatment of the donor compounds. The ability of model compounds representing coal to accept hydrogen is assessed from a comparison of the¹H n.m.r. spectra. It is established that donor and acceptor efficacies are dependent upon chemical structure.     

Model systems for photosynthesis acting as photoinduced molecular wires in bilayers

Sequential electron transfer are the key steps which determine the efficiency of the energy conversion processes in photosynthesis. An attempt at modelling the active natural reaction centers in the membrane environment is presented. Various triads and one tetrad, made up of electron donor and electron acceptor molecules, have been synthesized and incorporated into lipid bilayers. Photoelectrochemical measurements evidence a vectorial intramolecular and transmembrane electron transfer. The influence of the structure of the compounds on the photocurrents is discussed.     

Hydrogen-bonding-induced phenomena in bifunctional heteroazaaromatics

Ground and excited state processes induced by hydrogen bond formation are discussed for a family of heterocyclic compounds which possess both a proton donor (pyrrole NH group) and an acceptor (pyridine-type nitrogen). Excited state double proton transfer and rapid S(0) <-- S(1) internal conversion are observed only for molecules capable of forming cyclic, multiply hydrogen-bonded complexes. If the 1:1 cyclic, doubly hydrogen-bonded solvate is present in the ground state, the phototautomerization occurs even in rigid solvents at low temperatures. Internal conversion process requires solvent rearrangement and, therefore, does not proceed in a rigid environment. Another type of fluorescence quenching was also detected, involving photoinduced electron transfer from an excited chromophore to an aromatic hydrogen-bonded acceptor, such as pyridine. In molecules consisting of proton donor and acceptor units linked by a single bond, syn-anti rotamerization caused by hydrogen bonding is observed.     

Synthesis and characterization of novel diazenes bearing pyrrole, thiophene and thiazole heterocycles as efficient photochromic and nonlinear optical (NLO) materials

Two series of novel thermally stable second-order nonlinear optical (NLO) and photochromic chromophores have been designed and synthesized. The two series of compounds were based on different combinations of donor groups (pyrrole or thienylpyrrole) which act simultaneously as π-conjugated bridges, together with diazoaryl or diazothiazolyl as acceptor moieties. Their photochromic and electrochemical behavior were characterized, while hyper-Rayleigh scattering (HRS) was employed to evaluate their second-order nonlinear optical properties. The results of these studies have been critically analyzed together with two other related compounds reported earlier from our laboratories in which the thienylpyrrole system was used as the donor group keeping the functionalized diazoaryl as acceptor moiety. The measured molecular first hyperpolarizabilities and the observed photochromic behavior showed strong variations for the different donor systems used (pyrrole or thienylpyrrole) and were also sensitive to the acceptor strength of the diazenehetero(aryl) moiety.The thienylpyrrole based compounds endowed with extended π-conjugated bridges and stronger donor auxiliary effects in comparison to the pyrrole compounds, when coupled to the stronger acceptor diazo(hetero)aryl groups gave rise to significantly larger hyperpolarizabilities (β = 274-415 × 10⁻³⁰ esu) for an incident wavelength of 1064 nm. These compounds also displayed improved photochromic behavior with very fast response to the visible light stimulus (1.5 s) and fast thermal return to the original forms (2-3 s).     

Synthesis and characterisation of heterotrinuclear transition metal complexes for biomimetic proton reduction

Selected structural, spectroscopic, electrochemical and photochemical properties of novel heterotrinuclear [FeFe]-hydrogenase enzyme model compounds carrying a catalytic iron sulfur cluster site directly coupled to different transition metal subunits are reported. Typical metal-to-ligand charge transfer (MLCT) chromophores based on electron donating copper(I), rhenium(I) and tungsten(0) complex fragments were selected to provide both long-wavelength spectral sensitization and photoredox activity. Photoinduced one-electron transfer from the MLCT donor subunit to the diiron acceptor site could be observed with an efficient steady-state accumulation of the corresponding charge-separated state. The reduced iron site of these deeply coloured heterotrinuclear [FeFe]-hydrogenase model systems has been shown to be electrocatalytically active for proton reduction in the presence of trifluoroacetic acid (TFA). However, a successful visible-light powered system for catalytic hydrogen release in homogeneous solution could not be achieved, and the reaction remained stoichiometric with all of the systems investigated.