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1.
设计合成了一系列含席夫碱基的螺吡喃双功能光致变色材料4a~4n. 通过1H NMR, IR和HRMS对其结构进行了表征. 研究了化合物在几种溶剂和PMMA膜中的光致变色性质, 研究了化合物4a在甲醇中, 以及化合物4a和4f在高分子介质聚甲基丙烯酸甲酯(PMMA)中的消色过程. 结果表明, 化合物4e在PMMA膜中光照后呈现出与其它化合物不同的颜色, 为罕见的绿色. 化合物4a在二氯甲烷溶液中有良好的荧光性能. 所合成的新型含席夫碱基的螺吡喃双功能光致变色材料在甲醇、二氯甲烷和环己烷溶液中及在PMMA膜中均表现出良好的光致变色性质.  相似文献   

2.
以无乳化剂乳液聚合法合成聚甲基丙烯酸甲酯 (PMMA)和聚苯乙烯 (PSt)微球 ,分散聚合法合成荧光标记的PMMA微球 (FPMMA) .用激光共聚焦荧光显微技术 (LCFM )研究FPMMA/PMMA和FPMMA/PSt两种乳胶膜体系 (重量比均为1∶99)的表面及深层形态结构 .从不同深度层面的LCFM图象看出 ,从表面到本体内部 ,PMMA在PSt母相中明显聚集 ,而且PMMA在膜的纵向分布为在表面及接近基底的层面较少 ,主要分布于中间层面 .并对所得结果进行了讨论 .  相似文献   

3.
宋功武  吕少仿  何治柯  曾云鹗 《分析化学》1999,27(10):1183-1185
合成了2苯基(4溴)咪唑[f]邻菲咯啉(简称PIP(Ⅲ)新的配体及〔Ru(bpy)_2PIP(Ⅲ)]~(2+)新的络合物,用荧光光谱研究了络合物与小牛胸腺DNA分子的结合情况,在 pH7.4,络合物与DNA作用后,在587nm(λ_(ex)=471nm)产生很强的荧光峰,其发光强度与DNA浓度呈线性关系;线性范围0~1.2mg/L;检测限(3a(?))为2.8mg/L.该方法具有较高灵敏度和准确度,对合成样品测定,结果令人满意.  相似文献   

4.
双希夫碱稀土络合物的荧光性质   总被引:4,自引:0,他引:4  
尹伟  张迈生 《分析化学》2003,31(2):217-220
采用荧光光谱、紫外吸收光谱及红外吸收光谱对稀土元素钐、铽与双希夫碱N ,N′ 二 (亚水扬基 ) 1 ,4 二氨基丁烷、N ,N′ 二 (亚水扬基 ) 1 ,5 二氨基戊烷以及还原希夫碱N ,N′ 二 (水扬基 ) 1 ,4 二氨基丁烷合成的络合物进行了研究。双希夫碱和还原双希夫碱的N和O原子参与配位 ,形成络合物的荧光是以配体发光为主。当双希夫碱和TTA共存于同一络合物时 ,钐的络合物存在配体协同发光效应 ,表现为有较强Sm3+ 特征发光性能 (m →m型发光 ) ;而铽的络合物则以配体发光为主  相似文献   

5.
聚乙二醇基质中纳米乙酰丙酮铽的荧光特性研究   总被引:6,自引:1,他引:5  
在高分子聚乙二醇基质中制得了纳米乙酰丙酮铽的络合物并对其荧光特性进行了研究。结果表明,纳米乙酰丙酮铽的荧光光谱在峰位、峰形、峰强和主峰的半高宽等方面都与普通乙酰丙酮铽有明显差别。  相似文献   

6.
利用荧光光谱法研究了三聚氰胺(MEL)和Cu2+与8-苯胺-1-萘磺酸(ANS)的相互作用.研究表明,MEL和Cu2+均对ANS有荧光猝灭作用,且猝灭机理均为静态猝灭.计算了表观结合常数和结合位点数.Cu2+的引入使得MEL猝灭ANS荧光的效果急剧增强,体系的相对荧光峰强与MEL浓度(1×10-10~1×10-5 mol/L)的对数值呈良好的线性关系,三聚氰胺的检出限为3.8×10-11 mol/L.紫外、荧光、三维荧光光谱的结果表明,MEL及Cu2+对ANS的荧光猝灭为协同作用,三者形成了三元络合物.本研究建立了荧光光谱检测超痕量三聚氰胺的新方法,为奶粉、乳制品中三聚氰胺的检测提供了新思路.  相似文献   

7.
在 0.1 mol?L-1醋酸-醋酸钠(pH 5.0)体系中, 采用紫外吸收光谱、荧光光谱及同步荧光光谱法研究了人血丙种球蛋白(gamma seroglobulinum humanum, 简称 GSH)与铱(IV)离子的相互作用. 结果表明, Ir(IV)离子使人血丙种球蛋白的构象发生了改变, α-螺旋含量减少, 并且用同步荧光光谱发现 Ir(IV)离子与人血丙种球蛋白的作用位点更接近于色氨酸,从而使色氨酸残基的疏水性略有减小. 荧光光谱结果表明Ir(IV)对人血丙种球蛋白内源荧光(342 nm)产生了较强的荧光猝灭作用, 根据不同温度下 Ir(IV)对人血丙种球蛋白的荧光猝灭作用, 证明了这种荧光猝灭为静态猝灭机制, 计算了其结合常数和结合位点数, 从而得出了静电作用力为其主要的作用力.  相似文献   

8.
铱(IV)离子与人血丙种球蛋白的作用研究   总被引:8,自引:0,他引:8  
常希俊  黄艳  贺群 《化学学报》2005,63(3):223-228
在0.1 mol•L-1醋酸-醋酸钠(pH 5.0)体系中, 采用紫外吸收光谱、荧光光谱及同步荧光光谱法研究了人血丙种球蛋白(gamma seroglobulinum humanum, 简称GSH)与铱(IV)离子的相互作用. 结果表明, Ir(IV)离子使人血丙种球蛋白的构象发生了改变, α-螺旋含量减少, 并且用同步荧光光谱发现Ir(IV)离子与人血丙种球蛋白的作用位点更接近于色氨酸, 从而使色氨酸残基的疏水性略有减小. 荧光光谱结果表明Ir(IV)对人血丙种球蛋白内源荧光(342 nm)产生了较强的荧光猝灭作用, 根据不同温度下Ir(IV)对人血丙种球蛋白的荧光猝灭作用, 证明了这种荧光猝灭为静态猝灭机制, 计算了其结合常数和结合位点数, 从而得出了静电作用力为其主要的作用力.  相似文献   

9.
测得了长白山白眉蝮蛇毒精氨酸酯酶 1的最适反应的pH范围为 7.0~ 8.0 ,且与酶反应底物对甲苯磺酰-L -精氨酸甲酯 (TAME)的反应无明显的最适应反应温度 .荧光光谱的研究结果表明 :该酶的酪氨酸残基的荧光被色氨酸残基的荧光所掩盖 ;同步荧光光谱结果表明 :当发射波长与激发波长差Δλ分别为 2 0nm和 75nm时 ,精氨酸酯酶 1的荧光光谱分别由酪氨酸 (Tyr)和色氨酸 (Trp)残基所贡献 ,且处于亲水性环境中 ;精氨酸酯酶 1的荧光发射强度受溶液酸度变化的影响 .I- ,Acr和NBS对精氨酸酯酶 1的荧光淬灭结果表明这种酶中含有多个色氨酸残基 ,且处于不同的微环境中。  相似文献   

10.
N3染料对F-的高选择性光学传感性质   总被引:1,自引:0,他引:1  
采用紫外-可见吸收光谱和荧光光谱滴定方法研究了N3染料,cis-Ru(Hedcbpy)2(NCS)2(H2dcbpy=4,4'-二羧酸-2,2'-联吡啶),在二甲基亚砜(DMSO)溶液中对F-、Cl-和Br-的识别行为.结果表明,F-能引起N3的吸收光谱和荧光光谱的明显变化,能作为高选择性的荧光和比率色度F-专感器.N3与P相互作用产生一个大的荧光增强因子40,在已报道的基于Ru(Ⅱ)配合物的F-传感器中较为罕见.  相似文献   

11.
IntroductionThelow-temperatureprocessingofthesol-gelmaterialmakesitpossibletoentraporganicspecieseasilywithinarigidglassmatri...  相似文献   

12.
王筱梅  杨平  施琴芬  蒋宛莉  程晶磊 《化学学报》2003,61(10):1646-1652
利用还原偶联方法合成出新化合物四(4,4',4',4'-N,N-二氨基)四苯乙烯( TDETE)。通过测定该化合物在溶液、掺杂聚合物中及晶体粉末的稳态-瞬态荧光光 谱、荧光量子产率和辐射衰变速率常数等。讨论了分子的构象效应等因素对TDETE 光致发光行为的影响。在一定浓度下TDETE溶液存在着三个发光带,分别为全扭曲 构象分子(位于345nm附近的发光I带)、半扭曲构象分子(位于430nm附近的发光 II带)和激基缔合物(530发光III带)的辐射衰变所致。在聚合物(PMMA)中,一 方面由于分子单键的自由旋转扭曲受到遏制,表现为II带的辐射衰变速率常数(kf 值)增大、同时非辐射衰变速率常数knf值减小;另一方面,TDETE分子之间相互作 用得到加强而有利一缔合物形成,结果,使发光II带和III带合二为一出现强而宽 的发射峰,荧光量子产率从溶液中的0.055提高到0.855。此外,在PMM介制裁中观 测到TDETE分子聚集体在626nm处的发光带(IV),数粉末态中聚集体IV带的强度骤 增,峰值波长红移至650nm。  相似文献   

13.
ernary europium complex with dibenzoylmethane(DBM), 1,10-phenanthroline(phen) was in-situ syn thesized in thin SiO2/polyvinyl butyral(PVB) hybrid films by a two-step sol-gel process, characterized by means of fluorescence spectroscopy. The luminescence spectra, fluorescence lifetimes, photostability were all investigated. The results showed that the hybrid films exhibited the characteristic emission bands of the central rare earth Eu3+. In addition, Eu3+ presented longer fluorescence lifetime than in an ethanol solution, the complex had a higher photostability in the hybrid film than in the PVB film containing the corresponding pure complex.  相似文献   

14.
Summary A new method for the highly sensitive fluorometric determination of europium(III) as its benzoyltrifluoroacetone (BFA) complex with trioctylphosphine oxide (TOPO) without uncombined BFA in n-hexane has been established by means of solvent extraction and vacuum sublimation. The effect of various factors on the fluorescence intensity of europium(III) was investigated. The fluorescence intensity was measured at 620 nm against rhodamine B as an internal standard under the excitation at 335 nm. It was found that a heating treatment gave rise to the enhancement of the fluorescence intensity for about twice times compared with that without heating treatment. Excellent linearity of the calibration curve of europium(III) was obtained in the range of 0–100 ppb. A few ppb of europium(III) can still be detected with this method. All 13 rare earth metals and cobalt(II) tested gave a somewhat positive error. Aluminium(III), iron(III), and copper(II) caused a negative error. The interference of aluminium(III) and iron(III) was removed by extraction with 0.1 mol/l 8-quinolinol in chloroform at pH 4.0, while the problem of cobalt(II) and copper(II) was solved by masking with 0.1 mol/l Na2S2O3 in aqueous solution.
Hochempfindliche spektrofluorimetrische Bestimmung von Europium(III) als Benzoyltrifluoracetonkomplex mit Trioctylphosphinoxid mit Hilfe der Lösungsextraktion und Vakuumsublimation
  相似文献   

15.
Du X  Gao J  Xie Q  Kang J 《Talanta》1994,41(2):201-204
Synchronous derivative fluorescence of samarium, europium and terbium complexes with quinaldic acid and phenanthroline was examined in aqueous solution. The composition of these complexes was determined. The maximum emission wavelengths are 645 nm, 617 nm and 545 nm for samarium, europium and terbium, respectively. Under the optimal experimental conditions, the fluorescence intensity was a linear function of concentration in the range of 10-250 ppm for samarium, 0.5-50 ppm for europium and 0.5-300 ppm for terbium. Simultaneous determination of samarium, europium and terbium was successfully carried out for samarium oxide and middle rare earth mixture. The precision of the method, expressed as relative standard deviation, is within 1.1-2.5%.  相似文献   

16.
Superoxide dismutase (SOD) can enhance the characteristic fluorescence of europium in europium (Eu(3+))-tetracycline (TC) system. According to this, a new spectrofluorimetric determination of SOD was developed. Under the optimum conditions, Eu(3+)-TC formed a ternary complex in close proximity with SOD and then intra-molecular energy transfer from TC-SOD complex to Eu(3+), which resulted in the enhancement of characteristic peak of Eu(3+) at 612 nm. The enhanced fluorescence intensity is in proportion to the concentration of SOD, and the linear range was 0.0553-38.71 microg mL(-1) with the limit of detection of 5.53 ng mL(-1). The developed method was practical, simple, sensitive and relatively free from interference coexisting substances and has been successfully applied to the determination of SOD in the plant and blood samples. The mechanism of fluorescence enhancement between Eu(3+)-TC complex and SOD was also studied.  相似文献   

17.
在pH7.8的缓冲溶液中,铕离子、速尿和三辛基氧膦(TOPO)反应生成稳定的三元配合物,该配合物溶解在Triton X-100胶束中。以280 nm光波激发,配合物发射出铕离子的特征荧光。分析了三元配合物的紫外及荧光光谱,对配合物的生成及TOPO和Triton X-100的荧光增敏机理进行了探讨。采用时间分辨荧光法测定配合物的荧光强度,其荧光强度和速尿的浓度在一定范围内呈线性关系,建立了工作曲线的线性回归方程。方法的检出限为6.6×10-8mol/L,测定精度RSD为1.3%(4.00×10-6mol/L,n=11)。用此方法测定尿液中痕量速尿,回收率为93.0%~103%。  相似文献   

18.
The luminescence properties of four europium chelates with increasing benzene ring substituents ligand in poly(methylmethacrylate) (PMMA) have been investigated by fluorescence emission spectra and lifetime measurements. According to the fluorescence emission spectra, the Judd-Ofelt parameters Omega2, Omega4 of europium chelates-doped PMMA have been calculated and the radiative properties were also presented. It showed that the increase of benzene ring substituents in ligand can increase the metastable state lifetime tau(m), the luminescence quantum yield eta and the stimulated emission cross-section sigma of 5D0-->7F2 transition.  相似文献   

19.
Polyethylene oxide (PEO) oligomers can dissolve lanthanide salts. The terminal hydroxyl groups of PEO affect the solubility of the lanthanide salts in the PEO considerably. However, no intensive fluorescence was observed from Eu3+ dispersed in PEO or other ion-conductive polymers containing terminal hydroxyl groups, because of the quenching effect of the terminal hydroxyl groups. Copolymer of ω-methoxy oligo(oxyethylene) methacrylate and methyl methacrylate (P(MEOM-co-MMA)) could dissolve small amount of Eu(NO3)3, but the copolymer film containing Eu3+ shows intensive fluorescence (Ex = 269.0 nm, Em = 570.0 nm). This was prepared as a soft film, and there was a clear dependence of the Eu3+ concentration on the fluorescence intensity. A linear relation between the film thickness and the fluorescence intensity was also observed. Little fluorescence was found for Eu3+ in the blend of the corresponding two homopolymers, i.e. poly-(ω-methoxy oligo (oxyethylene) methacrylate) (PMEOM) and poly(α-methyl methacrylate) (PMMA). This strongly suggests that intensive fluorescence requires a mixed state of MEOM and MMA units at molecular level.  相似文献   

20.
A new unsymmetrical photochromic diarylethene, 1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(3-trifluoromethylphenyl)-3-thienyl]perfluorocyclopentene (1a), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. Its optical and electrochemical properties, including photochromic reactivity both in solution and in the solid state (PMMA film and the single-crystalline phase), fluorescence and electrochemical properties were investigated in detail. The compound showed excellent photochromism even in the single-crystalline phase by photo-irradiation. In acetonitrile, the open-ring isomer of diarylethene 1 exhibited relatively strong fluorescence at 470nm when excited at 300nm, and its emission intensity decreased along with the photochromism upon irradiation with 313nm light. Its closed-ring isomer showed almost no fluorescence. The electrochemical properties of diarylethene were investigated by performing cyclic voltammetry experiment and its HOMO and LUMO energy level were calculated.  相似文献   

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