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1.
An optode system based on a plasticized polymer membrane containing cesium ion-selective fluoroionophore and lipophilic anions for the determination of cesium ions has been developed. In this work, 15-crown-5 derivative including anthracene was used as a fluoroionophore. Emission intensity of the optode membrane incorporating 15-crown-5-anthracene was measured at 500 nm with excitation at 360 nm in the presence of Tris-HCl buffer solution. Under optimum experimental condition, the relative fluorescence intensity was linear with the concentration of cesium ion in the range of 1.0 × 10-4 M to 1.0 × 10-1 M and the detection limit was obtained 4.2 × 10-5 M, as defined by LOD = 3 × Sb/m (where Sb=standard deviation of blank signal and, m=slope of the calibration curve). The effect of pH of sample solution on the fluorescent response, the selectivity, response time and reproducibility of the optode membrane were also discussed. The fluorescent optode system shows a high selectivity and sensitivity for cesium ion with respect to other cations such as K+, Na+ and Li+.  相似文献   

2.
研究了15-冠-5(15-C-5)与Na2[Pd(SCN)4]的反应,得到的配合物[Na(15-C-5)]2[Pd(SCN)4]通过元素分析、红外光谱、单晶X射线衍射进行了结构分析.该配合物为单斜晶系,空间群C2/c,晶体学数据: a=1.3525(6)nm,b=1.3729(6)nm,c=2.0312(9)nm,β=102.985(6)°,V=3.675(3)nm3,Z=4,F(000)=1696,R1=0.0288,wR2=0.0457.结构分析表明,该配合物由两个[Na(15-C-5)]+配阳离子和一个[Pd(SCN)4]2-配阴离子组成,二者通过Na-N相互作用形成二维网状结构.  相似文献   

3.
A test based on time-resolved fluorescence experiments (Anal. Biochem. 245, 28–37, 1997) allows one to assess the interference of the excited-state association with the fluorimetric determination of the ground-state dissociation constant K d of fluorescent ion:indicator complexes. If an inflection point occurs in the plot of the fluorescence signal vs – log[ion] in the ion concentration range where both decay times are invariant, this inflection point can be associated with the correct K d. Here we apply this test to the fluorescent ion indicators SBFO (for Na+), Mag-fura-2 (for Mg2+), and APTRA-BTC (for Ca2+). In all three cases the decay times are invariant in the concentration ranges of the respective ions where the fluorescence titrations show unique inflection points, indicating that the fluorimetrically determined K d values are the true K d values.  相似文献   

4.
Luminescence properties and the x-ray structures of the fluorescent crown ether, 16-anthracen-ylmethyl-1,4,7,10,13-pentaoxa-16-aza-cyclooctadecane (CEA) and its complex with potassium hexafluorophosphate (CEAK) have been obtained. In the solid state CEAK gives a structured blue emission and CEA gives a broad structureless green emission. The differences in luminescence behavior are explained on the basis of crystal packing. X-ray analysis shows that every two adjacent anthracene moieties in CEA form a sandwich-like anti-parallel dimer; the green-structureless emission then arises from the π-π stack of the aromatic rings. In CEAK, disruption of the π-π stacking structure forces a large separation between the anthracene rings, which yields an anthracene monomer emission. Luminescence lifetime data support the assignments.  相似文献   

5.
冠醚铕镧异核配合物的合成表征及荧光性质   总被引:1,自引:0,他引:1  
以 18冠 6为配体 ,分别与高氯酸铕和高氯酸镧在乙腈介质中反应 ,合成冠醚铕和冠醚镧配合物 ;两种冠醚配合物与交联配体———对苯二甲酸反应 ,形成了对苯二甲酸冠醚铕镧异核稀土超分子配合物。由元素分析数据推测 ,超分子配合物的组成式为EuLaL2 L′(ClO4) 4 ·6H2   [L =18 C 6 ,L′ =p C6H4(COO-) 2 ],测定了超分子配合物的红外光谱 ,紫外光谱 ,摩尔电导及荧光光谱。结果表明 ,冠醚和对苯二甲酸根与稀土离子配位 ,而高氯酸根离子处于配合物的外界 ,铕镧异核稀土超分子配合物的荧光强度是冠醚铕的 8倍多。  相似文献   

6.
磷钼杂多酸-结晶紫分光光度法测定高纯氯化铯中微量磷   总被引:1,自引:0,他引:1  
张毅  汪明礼 《光谱实验室》2004,21(3):501-503
以 4 -叔丁基 - 2 (α-甲苄基 )苯酚 (t- BAMBP)萃取分离基体铯 ,磷钼杂多酸与结晶紫染料生成离子缔合物 ,在聚乙烯醇存在下 ,在水溶液中显色。在波长 5 45 nm处 ,其摩尔吸光系数可达 2 .0 1× 10 5L· mol-1·cm-1。方法的回收率为 97%— 10 1% ,相对标准偏差为 0 .8%— 2 .7%。  相似文献   

7.
用光学-光学双共振光谱技术研究Cs蒸气中的共振交换碰撞   总被引:1,自引:1,他引:0  
利用窄带半导体激光器泵浦所有具有相同z分量速度的基态Cs原子至激发态,研究了Cs(6P3/2, v) +Cs(6S1/2, v′)→Cs(6S1/2, v) +Cs(6P3/2, v′)的共振交换碰撞过程。与泵浦光反向平行的另一单模激光器激发6P3/2至8S1/2态,以检测6P3/2态原子的速度分布,确定激发态原子的热能化效应。通过测量8S1/2→6P1/2荧光的尖峰强度与相应的多普勒背景的强度比,得到共振交换碰撞速率系数为k=9.62×10-7 cm3·s-1。证明了在纯碱金属蒸气中,由共振交换机制产生的热能化效应的大小比由速度改变碰撞引起的大3个数量级。  相似文献   

8.
硫酸介质中,多塞平可以还原高锰酸钾,生成强荧光产物,其在激发波长336nm,发射波长465nm处的荧光强度与多塞平浓度有良好的线性关系,拟定了测定多塞平的荧光分析新方法。该方法操作简便,灵敏度高,背景低,选择性好,测定多塞平的线性范围为0.1—40mg/L,检出限为0.026mg/L,用于药物中多塞平的测定,获得了令人满意的结果,并对反应机理进行了探讨。  相似文献   

9.
研究了Cs蒸气被单模半导体激光器的852.3 nm线激发产生的荧光光谱。由Cs,Cs2的荧光及其强度确定了在受激Cs-Cs2系统中的若干碰撞和辐射过程。高位态原子线是由Cs(6P3/2)+ Cs(6P3/2)到Cs(6D,8S)的碰撞能量合并形成的,Cs2(B 1u)带则由Cs(6P)+Cs2(X 1Σ+g)碰撞转移产生。通过激发转移、能量碰撞合并和Cs2-Cs碰撞传能研究了6 2P原子的精细结构混合,得到了6P3/2→6P1/2碰撞转移速率系数是(5.2±2.1)×10-11 cm3·s-1,给出了过程Cs2(B 1∏u)+Cs(6S)→Cs2(X 1Σ+g)+Cs(6P1/2)的速率系数是(1.0±0.4)×10-9 cm3·s-1。  相似文献   

10.
A new cryptand compound carrying 2-hydroxy-1-naphthylidene Schiff base moiety (3) was designed and synthesized by reaction of the corresponding macrobicyclic amine compound (1) and 2-hydroxy-1-naphthaldehyde (2). The influence of metal cations such as Mg2+, Ca2+, Sr2+, Fe2+,Co2+, Mn2+, Zn2+, Cd2+, Hg2+, Al3+ and Pb2+ on the spectroscopic properties of the new fluoroionophore was investigated in acetonitrile-dichloromethane solution (9.5/0.5) by means of absorption and emission spectrometry. The blue shifts on the fluorescence spectrum were observed for all metal cations at 504nm. At the same time the fluorescence spectrum of the ligand showed quenching in the intensity of the signal at 504 nm for all metal cations except for Zn2+. Interaction of Co2+ with the ligand caused quenching of naphtyl fluorescence higher than 84%. The method showed good selectivity and sensitivity for Co2+ with respect to other metal cations with linear range and detection limit of 1.5 × 10−7 to 3.3 × 10−6M and 4.8 × 10−8M respectively.  相似文献   

11.
一些重金属离子即使在较低浓度时也会对环境、生物体产生毒性,所以研究痕量金属离子识别具有重大意义。荧光传感器由于具有选择性好、灵敏度高、成本低、实时响应等优点, 得到了广泛关注。以2,4-二叔丁基苯酚,3,5-二叔丁基水杨醛和邻氨基苯硫酚为原料合成了类Salen配体L1, 并用1H NMR,13C NMR,IR,元素分析及X射线单晶衍射等手段对其进行了表征。并通过自由挥发法得到了配体L1的单晶结构,实验表明L1是三斜晶、P-1空间群的一个空穴平面[ONSO]四配位环境。通过荧光光谱考察了类Salen配体与金属离子(Li+,Na+,K+,Cd2+,Cs+,Co2+,Cu2+,Hg2+,Mn2+,Ni2+,Zn2+,Ag+)的识别与配位性能。光谱滴定分析表明L1与Zn2+以1∶1的化学计量数配位。另外,L1与Zn2+结合后荧光显著增强,荧光检测限达到5.01×10-5 mol·L-1,而上述提到的其他常见金属离子不引起荧光光谱变化。结果表明L1是一个对检测Zn2+的选择性高,灵敏度强的荧光增强型探针。  相似文献   

12.
The photophysical and complexing properties of Rhod-5N (commercially available) in MOPS buffer are reported. This fluorescent molecular sensor consists of a BAPTA chelating moiety bound to a rhodamine fluorophore. Its fluorescence quantum yield is low and a drastic enhancement of fluorescence intensity upon cation binding was observed. Special attention was paid to the complexation with Cd2+, a well known toxic metal ion. Possible interference with other metal ions (Na+, K+, Mg2+, Ca2+, Zn2+, Pb2+) was examined. Rhod-5N was found to be highly selective of Cd2+ over those interfering cations except Pb2+. The limit of detection is 3.1 μg l−1.  相似文献   

13.
合成了稀土Eu3 ,Tb3 冠醚、对苯二甲酸高氯酸盐两个系列18种固态配合物。结果表明,配合物的组成为:Eu2LL′2(ClO4)4.4H2O、EuReLL′2(ClO4)4.nH2O、Tb2LL′2(ClO4)4.4H2O和TbReLL′2(ClO4)4.nH2O(Re:掺杂离子,n=2,3,4)。对苯二甲酸的羧基氧与稀土离子以对称螯合双齿配位;部分高氯酸在内界以单齿配位;配合物含有水分子。配合物的相对荧光光谱测定表明,相同配体的铽系列配合物的荧光强度明显强于铕系列。稀土离子Eu3 的5D0能级为17250cm-1,Tb3 的5D4能级为20430cm-1,而配体对苯二甲酸的三重态能级为25160cm-1,高于Eu3 和Tb3 离子的激发态能级,满足配合物分子内传能配体的三重态能级高于稀土离子发射能级的条件,可以提高Eu3 和Tb3 离子的特征荧光强度。但相对于Eu3 离子,对苯二甲酸的三重态能级与Tb3 离子的激发态能级(5D4)更匹配,更有利于能量的有效传递,因此,铽系列的荧光强度明显强于铕系列。Ho3 、Yb3 对Eu3 离子发光敏化作用最强,Ce3 、Sm3 、Dy3 、Er3 对Eu3 离子发光也有敏化作用,Pr3 、Nd3 离子对Eu3 离子的发光是猝灭的;Yb3 、Dy3 离子对Tb3 离子发光有较强敏化作用,而Ce3 、Pr3 、Nd3 、Sm3 、Ho3 、Er3 离子的掺入对Tb3 离子的发光是猝灭的。应用分子内能量传递过程对发光机理进行了探讨。  相似文献   

14.
以对氨基苯甲酸为母体通过系列化学衍生引入丹磺酰胺荧光基团及2-羟基-1-萘醛配位基团构筑了新型、简单的铬离子荧光探针L(1-(二甲基氨基)-5-(4-((2-羟基-1-萘亚甲基)甲酰肼基)苯基)萘磺酰胺)。运用核磁、质谱、元素分析和红外等手段表征了其结构,并通过荧光光谱法研究了探针分子L对Cr3+的识别作用。结果表明,当激发波长为350 nm时,单纯的探针分子L在473 nm(2-羟基-1-萘醛)和514 nm(丹磺酰胺)处显示连体双峰;当向探针分子L中加入Cr3+后,2-羟基-1-萘醛作为受体与Cr3+结合,丹磺酰胺发射峰红移至540 nm,并且强度增强5倍,量子产率Φ=0.28。探针分子L的背景荧光对Cr3+的识别无任何影响,识别过程推测是由CHEF效应和PET(光诱导电子转移)共同引起的。当加入其他金属离子(Na+,K+,Li+,Ca2+,Zn2+,Mn2+,Co2+,Cu2+,Cd2+,Hg2+,Pb2+,Ag+)时,在540 nm处荧光强度未增强,表明L对Cr3+具有高度专一的选择性。通过电喷雾质谱和Job’s plot 曲线确定L和Cr3+为1∶1的配位模式,探针L对Cr3+的最低检测限可达到4.0×10-6 mol·L-1。  相似文献   

15.
Novel electrogenerated chemiluminescence (ECL) reagents C1 , C2 , and C3 with high fluorescence quantum yields bearing 15‐crown‐5 moiety have been synthesized and characterized. The photophysical, electrochemical, and ECL characters of these compounds have been studied in a 1:1 (v/v) PhH/MeCN mixed solvent. The ECL intensity is enhanced distinctly with the increase in the fluorescence quantum yield. Their ECL behaviors have been studied using annihilation and co‐reactant methods (tri‐n‐propylamine (TPrA) was used as a co‐reactant), respectively. The stable ECL emissions of compounds C1 – C3 can be ascribed to the typical and simple monomer ECL emission via S‐route. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

16.
合成了荧光试剂水杨醛缩邻氨基苯酚,在NH4Cl-NH3·H2O缓冲溶液介质中,铅离子能使其荧光强度增强,荧光增强的程度随铅离子含量的增加而增大.据此建立了测定痕量铅离子的直接荧光分析方法.并研究此试剂与铅荧光反应的最佳条件,在λex/λem=386/502nm处,铅离子含量在0.0-200.0μg·L-1范围内与△F呈良好的线性关系,方法的检出限为1.62μg·L-1.该方法操作简便快速,具有极高的灵敏度.用于蓄电池废水中铅含量的测定,结果与火焰原子吸收光谱法基本一致,效果令人满意.  相似文献   

17.
For the fast characteristics of mixtures of Aluminium, Gallium and Indium the fluorimetric evaluation in the form of complexes with 8-Hydroxyquinoline-5-sulphonic acid is described at selected pH. The highly collinear correlated fluorescent spectra and their first derivation were evaluated under various experimental conditions with the Multiple Linear Regression (MLR), Partial Least Squares (PLS) methods and Kalman filtering. When comparing the results, the PLS gives the least relative prediction errors under optimal conditions, 5.6–15.9% for the concentration range of Al 0.025–0.2 μg cm−3, Ga 0.1–0.8 μg cm−3 and In 0.1–0.8 μg cm−3 in the mixture.  相似文献   

18.
铜、钠和钼离子与牛血清白蛋白作用的荧光光谱研究   总被引:6,自引:0,他引:6  
研究了铜、钠和钼离子对牛血清白蛋白(BSA)的荧光强度的影响。铜离子对牛血清白蛋白荧光有明显的静态猝灭现象,其离解常数为2.38×10-4 mol·L-1。氯化钠对BSA溶液的荧光没有影响,说明生理盐水作为生物系统的体液对生命起到很好的保护作用。而钼离子在小浓度时对牛血清白蛋白荧光静态猝灭比较小,当钼离子浓度增加到8.4×10-3 mol·L-1时,则呈现出雪崩猝灭现象。  相似文献   

19.
The effects of metal salts (NaCl, CaCl2·2H2O, EuCl3·6H2O and Eu(OAc)3) on the steady state and time resolved fluorescence behaviour of poly(para phenylene vinylene) oligomers containing benzo-15-crown-5 ether units (CE-OPV) have been investigated. The presence of EuCl3 causes a significant (8–9 fold) increase in the fluorescence emission intensity of the OPV segments, as compared to pure CE-OPV, in 99:1 methanol/chloroform solution and a small (9 nm) red shift in the emission maximum. The presence of Na+ or Ca2+ results in less marked increases in fluorescence intensity compared to Eu3+. In the presence of Eu3+ and Na+, the fluorescence intensity increases approximately linearly with metal ion concentration up to a metal ion/CE-OPV molar ratio of 10. The emission enhancement is not related to a simple 1:1 (CE-OPV:metal ion) complex formation process. In contrast, in acetonitrile, CE-OPV shows complex fluorescence quenching behaviour as a function of EuCl3 concentration. This solvent dependence suggests that the emission changes with metal concentration are related to the formation of charge-transferred complexes. The marked changes in fluorescence quantum yield of the PPV backbone due to complexation with metal ions makes CE-OPV a sensitive fluorescent probe for metal ions, or may be exploited for improving the quantum yield of PPV-based devices.  相似文献   

20.
The association constants, Ka of KI, Nal and CaCl2 complexing with 1,4,7,10,13-pentaoxacyclopentadecane and 1,4,7,10,13,16-hexaoxacycloocta-decane in DHO were determined by the aid of 13C dipole-dipole relaxation time measurements.

The mole fraction of the complexed ligand, PC were obtained by the use of the equation of 1/Tobs 1 - 1/T10 = PC (1/TO 1 - 1/T10) where the T10 and To 1 are the relaxation times of free and complexed macrocyclic ethers respectively.

Ka values obtained from the above given equation depending on the cation concentration, [A+ O] typically reflected the relation between the cationic radius and cyclic ether ring size.  相似文献   

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