含氟光敏单体液晶光控取向膜的光谱研究

制备了含氟光敏单体材料六氟戊二醇双肉桂酸酯,实验发现该材料在线性偏振紫外光辐照下可发生定向光交联反应.通过紫外可见光谱与红外光谱分析,表明光交联类型为[2 2]环加成反应.用原子力显微镜对单体光聚后形成的聚合物取向膜表面进行扫描,未观察到明显的各向异性分布现象.实验测得取向膜诱导液晶分子平行排列,取向效果均一,薄膜预倾角为1°～2°.     

咔唑类化合物的光致发光特性

聚二氯磷腈（PDCP）与N-（6-羟基己基）咔唑发生亲核取代,得到了热稳定性良好（约290 ℃）、玻璃化温度较低（约36 ℃）的光电导材料聚双（6-咔唑基己氧基）磷腈。稳态荧光光谱表明,N-（6-羟基己基）咔唑和聚双（6-咔唑基己氧基）磷腈的荧光发射最大波长分别在410 nm和393 nm,其荧光强度相比于咔唑的最大波长420 nm依次减弱并发生蓝移;瞬态荧光光谱表明聚磷腈的线型主链结构和孤立的d-p杂化轨道体系导致其空间位阻增大,破坏了原有的共轭体系,使聚双（6-咔唑基己氧基）磷腈在不同发射波长下的荧光寿命普遍减小。     

Synthesis and Solvent Polarity-Sensitive Photoluminescent Property of 4-Phenylethynyl-4'-Dimethylaminochalcone

以4-溴-4'-二甲氨基查尔酮和苯乙炔为原料,通过Sonogashira钯催化偶联反应合成了4-苯乙炔基-4'-二甲氨基查尔酮,并通过红外光谱和核磁共振氢谱对其结构进行了表征.进一步研究了4-苯乙炔基-4’-二甲氨基查尔酮在不同极性的溶剂中的紫外可见吸收光谱和荧光光谱,结果表明该化合物具有极性敏感的发光特性.     

4-苯乙炔基-4′-二甲氨基查尔酮的合成与溶剂极性敏感的发光特性

以4-溴-4′-二甲氨基查尔酮和苯乙炔为原料,通过Sonogashira钯催化偶联反应合成了4-苯乙炔基-4′-二甲氨基查尔酮,并通过红外光谱和核磁共振氢谱对其结构进行了表征。进一步研究了4-苯乙炔基-4′-二甲氨基查尔酮在不同极性的溶剂中的紫外可见吸收光谱和荧光光谱,结果表明该化合物具有极性敏感的发光特性。     

聚(2,5-二丁氧基)对苯乙炔/多壁碳纳米管复合材料的制备和性能研究

通过原位聚合法制备了聚（2,5-二丁氧基）对苯乙炔/多壁碳纳米管（PDBOPV/MWCNTs）复合材料.红外光谱和拉曼光谱证实了在MWCNTs表面的包覆层为PDBOPV.高分辨透射电子显微镜观察发现,PDBOPV/MWCNTs复合材料直径为35—45 nm,其中PDBOPV包覆层厚度约为15 nm.紫外—可见吸收光谱表明随着MWCNTs含量的增加,PDBOPV/MWCNTs的吸收发生红移且强度提高.荧光光谱研究表明随着MWCNTs含量的增加,PDBOPV/MWCNTs的最大发射波长发生蓝移且强度减小,MWCNTs与PDBOPV之间形成了光致电子转移体系,使得π电子离域程度增加,并且导致荧光量子效率降低.根据E_g与入射光子能量hν的关系,拟合了PDBOPV/MWCNTs薄膜的光学禁带宽度,发现随着MWCNTs的增加,E_g逐步减小.采用简并四波混频方法测试它们的三阶非线性极化率χ^（3）,结果发现随着MWCNTs含量的增加,PDBOPV/MWCNTs复合体的非线性光学响应逐渐增强,这说明PDBOPV与MWCNTs之间形成了分子间光致电子转移体系,产生了复杂的分子间π-π电子非线性运动. 关键词： 聚（2 5-二丁氧基）对苯乙炔 多壁碳纳米管 复合材料 光致发光     

查尔酮及其与丙二酸二乙酯Michael加成产物的合成与光谱学性质

以取代苯甲醛和苯乙酮,用水作溶剂,以碳酸钠为催化剂,制备了一系列查尔酮化合物.将所得查尔酮与丙二酸二乙酯及碳酸钾置于玛瑙研钵中常温无溶剂研磨,得到相应的Michael加成产物.采用紫外光谱和红外光谱法对合成出的查尔酮化合物以及相应的查尔酮与丙二酸二乙酯的Michael加成产物进行了分析,研究不同取代基对紫外吸收波长和红...     

光学相关论题 光化学

O644．1 2005053991 丙烯酸(4-N,N-二甲氨基肉桂酰氧乙基)酯及其水溶性聚 合物的合成及其光化学性质研究=Synthesis of(4-N,N- dimethylamine cinnamoylat ethyl)acrylate and its water soluble copolymers and their photochemical properties[刊, 中]／张锡兰(河南大学化学化工学院．河南,开封 (475001)),袁金芳…∥感光科学与光化学．-2005,23 (1)．-41-47 合成了一种新型感光性单体丙烯酸(4-N,N-二甲氨基 肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P (DMACEA-co-AA)。用紫外吸收和荧光光谱研究了聚合 物溶液的光敏感性,用傅里叶红外光谱研究了聚合物成膜 后的光交联性及其过程。结果表明,DMACEA具有较好 的光敏性,P(DMACEA-co-AA)具有较好光交联性,交联 膜水溶胀和透光性也较好。图4参8(于晓光)     

己氧基对含二苯乙烯基发色团化合物荧光性能的影响

合成了两种新型甲基丙烯酸酯类化合物：4-甲基丙烯酰氧基-4’-硝基二苯乙烯(NS)和4-甲基丙烯酰氧己氧基-4’-硝基二苯乙烯(HNS),通过红外光谱、核磁、高效液相色谱、紫外吸收光谱等对化合物结构进行了表征。研究了两化合物的荧光发射光谱,考察了浓度、溶剂极性等对化合物荧光发射光谱的影响。结果表明,化合物NS、HNS均存在浓度自猝灭效应,其荧光最大发射波长均随着溶剂极性增大而红移;且HNS由于供电子己氧基的引入在分子内形成了推-拉电子结构,使得其荧光最大发射波长较NS红移了72nm,化合物在DMF溶液中产生的荧光由黄光转变为橙红色光。     

光致变色Schiff碱N,N’-双(水杨醛缩)-1,2-环己二胺的荧光光谱

用稳态和时间分辨荧光光谱研究了Ｎ,Ｎ’ 双水杨醛缩 １,２ 环己二胺（Ｎ,Ｎ’ ｂｉｓ（ｓａｌｉ ｃｙｌｉｄｅｎｅ） １,２ ｃｙｃｌｏｈｅｘａｎｅｄｉａｍｉｎｅ,ＢＳＣ）在固态和四氯化碳、氯仿溶液中的光致变色行为。发现经过光照,ＢＳＣ的荧光光谱发生了明显、快速的改变,并且光致变色过程可重复进行。     

系列新型铕—β—二酮三元及四元混配化合物发光性质研究

本文报道了五种铕－β－二酮（二苯甲酰甲烷ＤＢＭ,噻吩甲酰三氟丙酮ＴＴＡ）－丙烯酸（ＨＡＡ）三元及四元混配化合物的紫外、荧光光谱,量子产率瞬态光谱。观察到主配体、协同配体对配合物吸收及发射光谱的影响。测得配合物溶液中铕离子＾５Ｄ１能级向＾５Ｄ０能级的传能过程及荧光寿命,发现室温下溶液中以ＴＴＡ为主配体的四元或三元配合物的寿命相近且远大于以ＤＢＭ为主配体的配合物。     

Modulation of a fluorescence switch of nanofiber mats containing photochromic spironaphthoxazine and D-π-A charge transfer dye

Photoswitchable poly(methyl methacrylate) (PMMA) nanofiber mats containing spironaphthoxazine (SPO)/electron donor-π-acceptor (D-π-A) type fluorescent dye (TCF) were prepared by electrospinning. The photoregulated fluorescence switching behaviors of SPO/TCF blended solution and PMMA nanofiber mats containing SPO/TCF were also studied. Not only SPO/TCF blended solution but also PMMA nanofiber mats containing SPO/TCF showed reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light.     

Photochromism of a novel asymmetrical diarylethene with a (formyloxyethoxy)ethyl‐linked naphthalimide moiety

A novel asymmetrical diarylethene with a (formyloxyethoxy)ethyl‐linked naphthalimide unit was synthesized, and its photochromic and fluorescence properties were systematically investigated in both solution and a poly(metyl methacrylate) film. The diarylethene showed significant photochromism and notable fluorescence switching properties upon irradiation with ultraviolet/visible light. Compared with the parent diarylethene, introduction of the naphthalimide moiety was effective to increase the molar absorption coefficient, the fluorescence quantum yield, and fluorescent modulation efficiency of the diarylethene. Copyright © 2014 John Wiley & Sons, Ltd.     

8—羟基喹啉铝的荧光老化机制

报导了８－羟基喹啉铝（Ａｌｑ３）在紫外光照射下发生荧光猝灭的机制,测量了Ａｌｑ３在光照射前后的紫外－可见吸收光谱、荧光光谱、红外吸收光电子能谱（ＸＰＳ）,分析了紫外光照射后Ａｌｑ３分子结构变化,证明了产生结构变化的根源是中水与Ａｌｑ３发生了化学反应,对Ａｌｑ３的我老化机制提出了可能的解释。     

Multiple switching behaviors of poly(N-isopropylacrylamide) hydrogel with spironaphthoxazine and D-π-A type dye

A multi-switchable poly(NIPAM-co-SPO-co-D-π-A dye) hydrogel with a photochromic spironaphthoxazine and an electron donor-π-conjugated-electron acceptor (D-π-A) type dye was prepared by typical radical copolymerization. The low critical solution temperature (LCST) behavior was investigated by UV–vis spectroscopy, which allows the measurement of the phase transition from 20 to 40 °C in aqueous solution. The fluorescence intensity of the poly(NIPAM-co-SPO-co-D-π-A dye) was temperature-dependent. Reversible modulation of fluorescence intensity was achieved using alternating irradiation with UV and visible light. Prepared polymer hydrogel also exhibited spectra change when not only used Cu²⁺ cation but also an acid unit.     

Magnetic Composite Thin Films of FexOy Nanoparticles and Photocrosslinked Dextran Hydrogels

Magnetic hydrogel composites are promising candidates for a broad field of applications from medicine to mechanical engineering. Here, surface-attached composite films of magnetic nanoparticles (MNP) and a polymeric hydrogel (HG) were prepared from magnetic iron oxide nanoparticles and a carboxymethylated dextran with photoreactive benzophenone substituents. A blend of the MNP and the dextran polymer was prepared by mixing in solution, and after spin-coating and drying the blend film was converted into a stable MNP-HG composite by photocrosslinking through irradiation with UV light. The bulk composite material shows strong mobility in a magnetic field, imparted by the MNPs. By utilizing a surface layer of a photoreactive adhesion promoter on the substrates, the MNP-HG films were covalently immobilized during photocrosslinking. The high stability of the composite was documented by rinsing experiments with UV-Vis spectroscopy, while surface plasmon resonance and optical waveguide mode spectroscopy was employed to investigate the swelling behavior in dependence of the nanoparticle concentration, the particle type, and salt concentration.     

A fluorescence switch based on a controllable photochromic naphthopyran group

A fluorescence switch based on photoisomerization of naphthopyran (NP) has been designed by employing 2-(pyridin-2-yl)-benzimidazole (BPI) and the naphthopyran containing two pyran rings (NP) as fluorescent dye and photochromic compound, respectively. The fluorescence switch of benzimidazole derivative can be modulated either by controlling the irradiation time of UV light or by adjusting the amount ratio of fluorescent benzimidazole derivative to photochromic naphthopyran in both solution and polymethyl methacrylate (PMMA) film. The experimental results indicated that the decrease of fluorescence intensity of benzimidazole derivative is attributed to the interaction of benzimidazole with naphthopyran.     

A Novel Porphyrin-Labeled Poly(N-Isopropylacrylamide): Spectral and Luminescent Properties

A novel water-soluble tetraarylporphyrin-containing polymer has been synthesized by the reaction of bromoalkyl-containing poly(N-isopropylacrylamide) with 5-(4-pyridyl)-10,15,20-tri(4-methoxyphenyl)porphyrin. Some physicochemical properties of the obtained polymers are reported. It has been shown that a strong interaction between the porphyrin units takes place in liquid aqueous medium at temperatures below the lower critical solution temperature (LCST). This phenomenon results in considerable broadening of the Soret band in the absorption spectrum and in strong quenching of fluorescence. Higher than LCST fluorescence enhancement is observed.     

紫外光辐照镍系聚丁二烯的NMR研究

用¹H NMR谱,¹³C NMR谱,二维谱,X-射线衍射等方法研究了镍系高顺式聚丁二烯橡胶(NiBR) 在强紫外（UV）光辐照前后的微观结构变化和分子运动情况. 分析表明NiBR样品随着UV光辐照时间的增加,侧链乙烯基端基双键比主链端基双键更易发生氧化反应;并且随着NiBR样品的各基团的半峰宽值逐渐增加,表明NiBR在UV辐照过程中发生了部分交联反应. 样品的X-射线衍射谱图中结晶峰强度随UV光辐照时间的增加逐渐降低,表明样品的晶形无序程度增加了. 自旋-晶格弛豫时间（T₁）和自旋-自旋弛豫时间（T₂）值给出了有关NiBR辐照前后分子运动变化的信息.      

Isomerization and fluorescence characteristics of sterically hindered azobenzene derivatives

We report synthesis and isomerization behaviors of sterically hindered azobenzene derivatives (1 and 2) with decyloxy and hydroxy groups, respectively, and their fluorescence enhancement under UV light irradiation characterized by means of absorption and fluorescence spectroscopy measurements. Upon irradiation of as-prepared solution (1) with UV light (∼200 mJ/cm²) a cis-rich photostationary state was reached. Obviously different from 2 showing very fast thermal cis-to-trans isomerization within 2 min, slow cis-to-trans thermal back isomerization of 1 with a long alkyl chain at ambient temperature was observed on the time scale of weeks. In contrast to no striking changes in absorption and fluorescence spectra of compound 2, the azobenzene 1 showed green fluorescence upon prolonged irradiation with UV light (about 3-8 J/cm² exposure doses), although both the initial trans-rich and cis-rich states of azobenzene molecules were not fluorescent in solution. The stability of fluorescence efficiency caused by drying and redissolving processes was examined.     

Photoactivated Green Fluorescence Emission by Femtosecond Oscillator from Indole Solutions

We reported a novel femtosecond-laser-activated fluorescence emission from indole solutions upon excitation by the second harmonic wavelength of a femtosecond oscillator. A new absorption band around 400 nm and corresponding fluorescent band in the green domain were produced after the irradiation of femtosecond laser. This femtosecond-laser-activated luminescence process that allows the use of visible wavelength as a substitute for UV light to excite fluorescence from indole would extend applications based on indole chromophore. Furthermore, the photoactived emission can act as a fluorescence lifetime probe to measure the polarity in complex biological systems since it is polarity-sensitive. High performance liquid chromatography with fluorescence detector (HPLC-FLU) and high performance liquid chromatography with mass spectrometer (HPLC-MS) analysis demonstrate that the origin of the photoactivated fluorescence is new molecular species that generated in indole solution upon femtosecond laser irradiation.