一种基于吗啉衍生物的Fe3+/Cu2+荧光探针

以9-蒽醛为荧光基团,吡唑和吗啉为识别基团,合成了一种荧光分子探针4-((3-(1-苯基-5-吡啶基-4,5-二氢-1H-吡唑-3-基)蒽-9-基)甲基)吗啉(L)。其结构经1H NMR、13C NMR表征,利用荧光发射光谱和紫外吸收光谱研究其离子识别性能。结果表明,探针L对Fe~(3+)和Cu~(2+)具有较强的选择性识别性能,荧光量子产率分别从0.47降到0.21和0.14;探针L的溶液颜色分别从淡黄色变为棕褐色和蓝色,裸眼可判断探针L选择性识别Fe~(3+)和Cu~(2+)。另外,根据Fe~(3+)、Cu~(2+)和H+不同组合时探针L的量子产率构建了分子水平上的三输入"NOR"逻辑门电路。     

基于2,6-二甲酰基-4-甲基苯酚的双Schiff化合物的合成及Zn~(2+)识别

以2-氨基苯并噻唑、水合肼和硫酸为原料,合成2-肼基苯并噻唑,与2,6-二甲酰基-4-甲基苯酚进行反应得到2,6-二甲酰基-4-甲基苯酚缩二(2-肼基苯并噻唑)(L),在DMF与H_2O (3:2,V:V)的混合溶液中,通过紫外和荧光测定该探针(L)对金属离子的识别性能。结果发现,该荧光探针(L)对Zn~(2+)具有较好的选择性和灵敏度,探针溶液的荧光强度与Zn~(2+)有良好的线性关系,线性方程为I=196.46+1654.12c,相关系数R~2=0.9864,检出限为38.5 nmol/L。该方法可以定量检测水中Zn~(2+)。     

间-双(2′-N,N′-苯甲胺基-1-萘基)甲氧基苯的合成及对Fe~(3+)和Cu~(2+)的荧光传感性能

以间二甲苯、水杨醛和α-萘胺等为原料合成了荧光化学传感器1,并经红外、核磁、质谱表征了产物的结构.用紫外光谱、荧光光谱滴定实验的方法研究了金属离子和化合物的相互作用.结果表明传感器1对Cu~(2+)和Fe~(3+)表现出高选择性荧光响应,受常见离子干扰较小,化合物1与Cu~(2+)和Fe~(3+)结合形成1∶1的配合物,其结合常数分别为(2.83±0.42)×10~3和(8.69±0.32)×10~3 L·mol~(-1),检出限分别为2.584 4×10~(-4)和1.234 2×10~(-5) mol·L~(-1).     

一种对Fe2+和Fe3+识别的显色试剂合成与应用研究

以罗丹明6G、水合肼及邻香兰素为原料设计合成了一种新型光学探针(P1),其结构经~1H-NMR,~(13)C-NMR,MS及元素分析进行表征。通过紫外-可见光谱法研究了探针对金属离子的识别能力。结果表明,探针P1在甲醇/Tris-HCl缓冲(V/V=3∶7,pH 8.34)溶液中无色,随着Fe~(2+)或Fe~(3+)的加入,溶液由无色转变为红色,其最大吸收波长为526 nm。最佳测量条件下,在1×10~(-6)～1×10~(-5) mol·L~(-1)范围内,Fe~(2+)或Fe~(3+)的浓度与吸光度线性关系良好(Fe~(2+),R~2=0.950;Fe~(3+),R~2=0.992)。探针与Fe~(2+)或Fe~(3+)形成1∶1型配合物,络合常数分别为K_(Fe)~(2+)=1.834×10~(5 )M~(-1)、K_(Fe)~(3+)=1.457×10~(5 )M~(-1),识别过程均不可逆。除了高浓度Cu~(2+)对探针识别Fe~(2+)或Fe~(3+)有影响外,其它常见金属离子没有干扰。P1有望发展成为裸眼识别Fe~(2+)和Fe~(3+)的高选择性探针。     

一种荧光增强型三价金属离子荧光探针的合成及性质

设计合成一种新型罗丹明类探针L,并研究了其光谱性质.实验结果表明,L在甲醇/水[V∶V=8∶2,c(Tris)=10mmol/L,pH=7.2]体系中对三价金属离子(Cr~(3+)、Fe~(3+)、Al~(3+))具有荧光增强性响应,很好的选择性和较高的灵敏度,不受其它二价及一价金属离子的影响,抗干扰能力强.探针L对Cr~(3+)、Fe~(3+)、Al~(3+)的紫荧光检测限分别为2.1×10~(-4)、2.3×10~(-4)和4.4×10~(-4) mol/L,表明其在各种水体样品中对三价金属离子的检测具有潜在的应用价值.     

基于苯并噻唑单元的Fe~(3+)荧光探针的合成及细胞成像应用研究

设计并合成了新型基于苯并噻唑的荧光探针L1和L2。通过荧光光谱滴定实验研究了其在DMSO/H_2O(1∶1,V/V,HEPES,p H=7.2)中对Li~+,Na~+,K~+,Ag~+,Cu~(2+),Ni~(2+),Zn~(2+),Mn~(2+),Cd~(2+),Hg~(2+),Co~(2+),Mg~(2+),Ca~(2+),Ba~(2+),Al~(3+),Cr~(3+),Fe~(3+)等不同金属离子的选择性识别能力,结果表明,探针对Fe~(3+)表现出较高的选择性,并与Fe~(3+)形成1∶1配合物,络合常数为(2.36×10~3)。其他常见金属离子的存在对铁离子引起的荧光淬灭无影响。探针L2还被用于活细胞中铁离子的检测。     

一种苯并噻唑-罗丹明衍生物的合成及其对Fe~(3+)、Al~(3+)、Cr~(3+)的识别

以罗丹明B为原料,通过"点击化学"合成和表征了一种苯并噻唑-罗丹明类双通道比色和荧光增强型探针(L),并研究了其光谱性质.实验结果表明,在甲醇溶液中L对三价金属离子Fe~(3+)、Cr~(3+)和Al~(3+)具有较高的选择性和灵敏度,不受其它二价金属离子及一价金属离子影响,抗干扰能力强.探针L对Fe~(3+)、Cr~(3+)和Al~(3+)的检测限分别为9.7×10~(-5)、6.9×10~(-5)、1.4×10~(-4) mol/L,表明对Fe~(3+)、Cr~(3+)和Al~(3+)检测具有潜在的应用价值.     

三嗪衍生物荧光探针对Zr~(4+),Fe~(3+)和丙酮的识别（英文）

一锅法合成了2,2',2'-(1,3,5-三嗪-2,4,6-三亚胺基)三苯甲酸荧光响应化学传感器(L,H_3TATIB),系统地研究了化合物L对过渡金属离子的识别性能.实验结果显示,在N,N-二甲基甲酰胺(DMF)水溶液中实现了对Fe~(3+)和Zr~(4+)的识别;化合物L在有机溶剂识别中能够有效地识别丙酮.化合物L对Zr~(4+)和Fe~(3+)的检测限分别为3.60×10~(-6)和1.33×10~(-6)mol/L.实验初步探究了化合物L作为荧光探针对人体尿液和水样中Fe~(3+)离子的识别.     

新型双功能席夫碱荧光探针分别识别检测Zn~(2+)和CN~-

合成了一种新的席夫碱荧光探针4'-羟基-3'-((2-吡啶亚甲基亚氨基)甲基)-4-氰基联苯(HPBC),用于对Zn~(2+)和CN~-的选择性识别检测。在Et OH-H_2O(2∶3,V/V,HEPES,p H=7.4)体系中,HPBC与Zn~(2+)按摩尔比1∶1络合,使探针在468 nm处的荧光明显增强,且最大发射峰发生15 nm的蓝移,而在加入其它金属离子后不产生明显的荧光增强现象,由此可以选择性识别检测水体系中的Zn~(2+)。本方法检测Zn~(2+)的线性范围为0.4~4.0μmol/L,检出限为36.5 nmol/L,比WHO规定的饮用水中Zn~(2+)限量水平(76μmol/L)约低1000倍。向HPBC中交替加入Zn~(2+)和EDTA,探针表现出"ON-OFF-ON"模式的荧光变化,且在4次循环后,体系荧光效率损失较小,表明HPBC对Zn~(2+)的识别具有良好的可逆性。荧光成像实验表明,HPBC可用于检测活细胞中的Zn~(2+)。而在DMSO-H2O(3∶7,V/V)介质中,由于与其它阴离子尤其是F~-与AcO~-相比,CN~-具有较强的碱性及较弱的氢键结合力,因此CN~-可使探针HPBC中的酚羟基去质子化,产生强的绿色荧光,且溶液颜色由无色变为淡黄色。由此可以选择性识别检测水溶液中的CN~-,且不受其它阴离子的干扰。HPBC对CN~-的检出限0.575μmol/L。HPBC还可制成试纸条,通过检测试纸条颜色及紫外灯下荧光的改变,方便快捷地检测水样中的CN~-。     

一种罗丹明衍生物的合成及其对三价金属离子(Fe~(3+)、Cr~(3+)和Al~(3+))的识别

三价金属离子(Cr~(3+)、Fe~(3+)和Al~(3+))与人体健康密切相关。目前,检测Cr~(3+)、Fe~(3+)和Al~(3+)需要采用不同的荧光探针,增加了检测成本和检测时间。发展能够同时检测Cr~(3+)、Fe~(3+)和Al~(3+)的高灵敏度和强抗干扰能力的荧光探针具有非常重要的意义。本文以罗丹明B为原料,合成和表征了一种罗丹明类荧光增强型探针(P),并研究了其光谱性质。研究表明,在V(甲醇)∶V(水)=9∶1体系中对三价金属离子Fe~(3+)、Cr~(3+)和Al~(3+)具有较高的选择性,不受其它二价金属离子及一价金属离子的影响,抗干扰能力强。同时,探针P对三价金属离子具有较高的灵敏度,对Cr~(3+)、Al~(3+)和Fe~(3+)的检测限分别为3.0×10~(-4)、2.7×10~(-4)和1.0×10~(-4)mol/L,表明其可用于Cr~(3+)、Al~(3+)和Fe~(3+)的检测。     

Recombination of KrD and XeD ions with electrons

Recombination rate coefficients of protonated and deuterated ions KrH⁺, KrD⁺, XeH⁺ and XeD⁺ were measured using Flowing Afterglow with Langmuir Probe (FALP). Helium at 1600 Pa and at temperature 250 K was used as a buffer gas in the experiments. Kr, Xe, H₂ and D₂ were introduced to a flow tube to form the desired ions. Because of small differences in proton affinities of Kr, D₂ and H₂ mixtures of ions, KrD⁺/D₃⁺ and KrH⁺/H₃⁺ are formed in the afterglow plasma, influencing the plasma decay. To obtain a recombination rate coefficient for a particular ion, the dependencies on partial pressures of gases used in the ion formation were measured. The obtained rate coefficients, α_KrD+(250 K) = (0.9 ± 0.3) × 10⁻⁸ cm³ s⁻¹ and α_XeD+(250 K) = (8 ± 2) × 10⁻⁸ cm³ s⁻¹ are compared with α_KrH+(250 K) = (2.0 ± 0.6) × 10⁻⁸ cm³ s⁻¹ and α_XeH+(250 K) = (8 ± 2) × 10⁻⁸ cm³ s⁻¹.     

A kinetic study of the oxidation of hydroxamic acids by compounds I and II of horseradish peroxidase: Effect of transition metal ions

Abstract

Oxidation of hydroxamic acids (HXs) generates HNO, and it is not clear whether it is formed also in the presence of metal ions. The kinetics of the oxidation of HXs, such as acetohydroxamic acid, suberohydroxamic acid, and suberoylanilide hydroxamic acid (SAHA), by compounds I and II of horseradish peroxidase (HRP) at pH 7.0 and 25?°C have been studied using rapid-mixing stopped-flow. The kinetics of these reactions were compared to those observed in the presence of Cu(ClO₄)₂, NiSO₄, or ZnSO₄. The rates decrease upon increasing [Cu^II] at constant [HXs], and no oxidation of HX occurs when [HX]/[Cu^II] ≈ 2, implying that HX oxidation in the presence of Cu^II proceeds through the free ligand since the predominant complex is CuX₂. In the case of Ni^II, the oxidation rate decreases upon increasing the ratio [Ni^II]/[HX] beyond 1, where the predominant complex is Ni^IIX⁺, implying that its oxidation is feasible. The effect of Zn^II could be studied only on the rate of HXs oxidation by compound II demonstrating similar behavior to that of Ni^II. HXs were also oxidized catalytically by HRP/H₂O₂ at pH 7.0, demonstrating that metal ions facilitate the formation of HNO while hardly affecting its yield and the extent of HX oxidation.     

Orthogonal Wavelets Analysis of Electroanalytical Signals

ABSTRACT

A signal processing technique based on orthogonal wavelet analysis is applied to process various simulated electroanalytical signals. The results indicate that if the scale parameters are selected, the orthogonal wavelet processing method (OWPM) can remove high-frequency noise. Experimental signal was recorded by computer and used to test the OWPM procedure. After processing with OWPM, the processed data was used to analyze the mechanism of the electrode reactions. Processed results of the experimental data are also satisfactory.     

Coordinate Structures of PrIII, GdIII, TmIII, and YbIII Complexes with Nitrilotriacetic Acids

The crystal and molecular structures of the [Pr^III(nta)(H₂O)₂]·H₂O (nta = nitrilotriacetic acids), K₃[Gd^III(nta)₂(H₂O)]·6H₂O, and K₃[Yb^III(nta)₂]·5H₂O complexes have been determined by single-crystal X-ray structure analyses. In [Pr^III(nta)(H₂O)₂]·H₂O, the Pr^IIINO₈ part forms a nine-coordinate pseudo-monocapped square antiprismatic structure in which one N and three O atoms are from one nta ligand in the same molecule, three O atoms from another nta ligand in the neighboring molecule and two O atoms from two coordinate water molecules. In K₃[Gd^III(nta)₂(H₂O)]·6H₂O, the [Gd^III(nta)₂(H₂O)^3- complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which each nta acts as a tetradentate ligand with one N atom of the amino group and three O atoms of the carboxylic groups. In K₃[Yb^III(nta)₂]·5H₂O, each nta also acts as a tetradentate ligand with one N atom of amino group and three O atoms of the carboxylic groups, but the [Yb^III(nta)₂ ^3- complex anion has an eight-coordinate structure with a distorted square antiprismatic prism. All the results including those for [Tm^III(nta)(H₂O)₂]·2H₂O confirm the inferences on the coordinate structures and coordination numbers of rare earth metal complexes with the nta ligand.     

Possibilities of multinuclear NMR in the chemistry of heteroorganic compounds

Results of multinuclear NMR studies of some heteroorganic compounds have been presented.According to a report at the conference «Current problems of organometallic chemistry» (May 8–13,1994, Moscow).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 614–616, April, 1994.     

Rotational molecular motion and solvation of Na+ and Cs+ in water-dimethylacetamide. A nuclear magnetic relaxation study

Nuclear magnetic relaxation by intra- and intermolecular quadrupoleelectric field gradient interaction has been used for the study of the systems DMA-water-NaI and DMA-water-CsI at 25°C.¹⁴N relaxation of DMA and²H relaxation of D₂O measured over the complete mixture range reveal the behavior of the rotational molecular motion of the two solvent components. For both solvent components a marked maximum of the reorientational correlation time has been found, reflecting hydrophobic effects and strong DMA-water interaction. The quadrupolar relaxation rates of²³Na⁺ and¹³³Cs⁺ in pure DMA were evaluated giving an indication that the electric solvent dipoles in the solvation shell are not located on positions of cubic symmetry. A quantitative study of preferential solvation of the cations in the mixed solvent has been performed by using the H₂O-D₂O isotope effect on²³Na⁺ and¹³³Cs⁺ relaxation. For both cations an obviously typical change in the selectivity occurs. In the range l>x _{H2 O}>0.7 we find weak preferential hydration, but in the range 0.7>xH ₂ O>0 strong preferential solvation by DMA is reflected.     

Counting performance and resolution of an HPLC radioactivity monitor

Summary Preliminary investigations clearly demonstrate the potential application of a solid scintillator to count beta emitters in the effluent streams from HPLC systems. Counting efficiencies of 6% for³H; 70% for¹⁴C; 10% for³²P; 72% for¹²⁵I were obtained. Spectra resolution permits practical application of simultaneous radionucleide monitoring.     

Recombination of HCO and DCO ions with electrons

Recombination of HCO⁺ and DCO⁺ ions with electrons was studied in afterglow plasma. The flowing afterglow with Langmuir probe (FALP) apparatus was used to measure the recombination rate coefficients and their temperature dependencies in the range 150–270 K. To obtain a recombination rate coefficient for a particular ion, the dependencies on partial pressures of gases used in the ion formation were measured. The variations of α_HCO⁺(T) and α_DCO⁺(T) seem to obey the power law: α_HCO⁺(T) = (2.0 ± 0.6) × 10⁻⁷ (T/300)^−1.3 cm³ s⁻¹ and α_DCO⁺(T) = (1.7 ± 0.5) × 10⁻⁷ (T/300)^−1.1 cm³ s⁻¹ over the studied temperature range.     

The Synthesis of Dibenzo[3n]crown-n by Novel Methods and their Cation Binding Studied by Fluorescence Spectroscopy. Part IV

The dibenzo[3n]crown-n were synthesised from1,2-bis(o-hydroxyphenoxy)ethane obtained from 1,2-bis(o-formylphenoxy)ethane via Bayer-Willigeroxidations with H₂O₂/CH₃COOH in good yields. The cyclic condensation of 1,2-bis(o-hydroxyphenoxy)ethanewith dichlorides, and ditosylates of polyethylene glycols in DMF/Me₂CO₃ gave the macrocyclesdibenzo[15]crown-5, dibenzo[18]crown-6, dibenzo[21]crown-7 anddibenzo[24]crown-8. The structures were identified using IR, mass, ¹H and ¹³C NMR spectroscopy. Therecognition of the molecules for the cations, Li⁺, Na⁺, K⁺, Rb⁺ and Zn²⁺were conducted quantitatively with steady state fluorescencespectroscopy. The 1:1 association constants in acetonitrileshowed a good relation of the appropriate size of the macrocyclic ether towards the fitting cationradii. Namely, dibenzo[15]crown-5 was the best for Li⁺ binding and more than 100 times better thanNa⁺ and K⁺. Dibenzo[21]crown-7 was excellent for Rb⁺ binding while K⁺ is 100 timesless preferred. The largest crown ether studied, dibenzo[24]crown-8, exhibited the order of binding power,Rb⁺ > K⁺ > Na⁺. Zn²⁺ displayed, however, a marked binding with only dibenzo[18]crown-6.p>     

The Synthesis of Novel Crown Ethers, Part VII [1]. Coumarin Derivatives of Benzocrowns and Cation Binding from Fluorescence Spectra

4-[3-(1-benzopyran-2-one)] derivativesof benzo[12]crown-4, benzo[15]crown-5 andbenzo-[18]crown-6 were synthesized from4-[3-(1-benzopyran-2-one)]-1,2-dihydroxy-benzenereacting with bis-ethyleneglycol dihalides orpentaethylene glycol ditosylate in alkali carbonate/DMF/water. The original products were identified byhigh resolution EI-mass spectra as well as IR,¹H-NMR and ¹³C-NMR spectroscopy. The 1 : 1binding constants of Mg²⁺, Li⁺, Na⁺ andK⁺ with the coumarin-benzocrowns were estimated usingfluorescence emission spectroscopy in acetonitrile.The complexing enhanced quenching fluorescence spectra(CEQFS) and complexing enhanced fluorescence spectra(CEFS) exhibited the ion binding powers due tocationic recognition rules of the macrocycles.