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1.
We reported a difluoroboron β-diketonate dye that displays bright red/NIR fluorescence in both solutions and solid states.  相似文献   

2.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.  相似文献   

3.
A series of fluorescent chemosensors 1-3 were synthesized to detect transition metal ions. At the room temperature, fluorescence intensities of these chemosensors in acetonitrile without transition metal ions were found to be very weak, due to the process of the e±cient intramolecular photoinduced electron transfer (PET). However, after addition of the transition metal ions, the chemosensor 1-3 exhibits obvious fluorescence enhancement. Moreover, the intensity of the fluorescence emission of chemosensors increases significantly in the presence of Zn2+ and Cd2+. The fluorescent chemosensors with different polyamine as receptors show diverse a±nity abilities to the transition metal ions and signal the receptor-metal ion interaction by the intensity change of fluorescence emission.  相似文献   

4.
Molecular switches 1 with a modular architecture whose functional principle is based on conformational changes around two acetylene axes were developed. By systematic screening of various metal ions, it was found that especially Pb2+ ions effectively trigger the switching event. The reporting of this event takes place by the change of the ratio between excimer and monomer fluorescence emission of two pyrene moieties.  相似文献   

5.
交联壳聚糖的结构及其对不同金属离子的吸附性能   总被引:13,自引:0,他引:13  
交联壳聚糖的结构及其对不同金属离子的吸附性能;交联壳聚糖;Cu2+;Co2+;Ni2+;结构;吸附性能  相似文献   

6.
陈洁  赵鑫  陈金平  李嫕 《物理化学学报》2007,23(11):1696-1700
合成了一系列外围带有咔唑, 核心带有或不带有氮杂冠醚结构的1-3代芳醚树枝形聚合物(CZ-Gn-CR, CZ-Gn-OH, n=1-3). 利用光物理方法研究了金属离子Li+、Na+、K+、Ca2+、Cu2+、Zn2+、Eu3+和Tb3+与树枝形聚合物之间的相互作用. 研究表明, Eu3+、Tb3+和Cu2+通过静态过程猝灭树枝形聚合物的荧光, 测定了Eu3+、Tb3+和Cu2+对CZ-Gn-CR、CZ-Gn-OH荧光的猝灭速率常数; 核心的冠醚结构可以增强树枝形聚合物与金属离子的相互作用. Li+、Na+、K+、Ca2+和Zn2+对CZ-Gn-CR和CZ-Gn-OH的紫外吸收光谱和荧光光谱均没有明显影响.  相似文献   

7.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.  相似文献   

8.
In this work, we synthesized amino thiol surfactants, namely, 10-(4-aminophenoxy)-decane-1-thiol and 12-(4-aminophenoxy)-dodecane-1-thiol. The self-assembling of the synthesized surfactants on gold nanoparticles (AuNPs) was investigated using different techniques such as ultraviolet analysis, x-ray diffraction, and transmission electron microscopy. The synthesized surfactants show the ability to assemble on gold nanoparticles and form stable nanostructure with it. We used the synthesized surfactants and their nanostructures with gold nanoparticles for the detection of Zn and Ni ions in aqueous solution using the ultraviolet spectrophotometer technique. The synthesized amino thiol surfactants showed the ability to detect Zn and Ni ions at low concentration. The results showed that gold nanoparticles can enhance the detection of Zn and Ni ions using the nanostructures of the synthesized surfactants.  相似文献   

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Bioremediation of heavy metal ions by phosphate‐mineralization bacteria (PMB), as a new green and en‐ vironmental method, relies on microbe‐inducing phosphate precipitation and can prevent heavy metal ions from transferring. The growth of PMB was investigated via four aspects respectively — the control of incubation time, pH value, environmental conditions, and heavy metal ions. At the same time, phosphate? mineralization precipitations and mechanism of four common kinds of heavy metal ions were analyzed. The experimental results indicated that PMB didn’t grow immediately in the first 5 hours, and they reached to the fastest reproduction rate after 13 hours. The pH value of PMB solution increased gradually from 7.0 to 8.6 when PM0B grew, which plays an important role in the mineralization process. PMB could grow most rapidly at 30 °C, pH of 8 and low concentration of heavy metal ions. It showed that too high or too low temperature and pH, as well as high concentration of heavy metal ions, could inhibit the reproduction of PMB. Stable and large particles phosphate ‐ mineralization precipitation, whose particle size could be more than 10 microns, were obtained by the process that PMB induced substrate to decompose and thus mineralized heavy metal ions effectively.  相似文献   

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In this study, a novel biomass adsorbent based on activated carbon incorporated with sulfur-based binary metal oxides layered nanoparticles (SML-AC), including sulfur (S2), manganese (Mn), and tin (Sn) oxide synthesized via the solvothermal method. The newly synthesized SML-AC was studied using FTIR, FESEM, EDX, and BET to determine its functional groups, surface morphology, and elemental composition. Hence, the BET was performed with an appropriate specific surface area for raw AC (356 m2·g−1) and modified AC-SML (195 m2·g−1). To prepare water samples for ICP-OES analysis, the suggested nanocomposite was used as an efficient adsorbent to remove lead (Pb2+), cadmium (Cd2+), chromium (Cr3+), and vanadium (V5+) from oil-rich regions. As the chemical structure of metal ions is influenced by solution pH, this parameter was considered experimentally, and pH 4, dosage 50 mg, and time 120 min were found to be the best with high capacity for all adsorbates. At different experimental conditions, the AC-SML provided a satisfactory adsorption capacity of 37.03–90.09 mg·g−1 for Cd2+, Pb2+, Cr3+, and V5+ ions. The adsorption experiment was explored, and the method was fitted with the Langmuir model (R2 = 0.99) as compared to the Freundlich model (R2 = 0.91). The kinetic models and free energy (<0.45 KJ·mol−1) parameters demonstrated that the adsorption rate is limited with pseudo-second order (R2 = 0.99) under the physical adsorption mechanism, respectively. Finally, the study demonstrated that the AC-SML nanocomposite is recyclable at least five times in the continuous adsorption–desorption of metal ions.  相似文献   

14.
李伟  罗磊  张淑贞 《化学进展》2011,23(12):2576-2587
发生在环境界面的吸附-解吸和氧化-还原等反应对于污染物在环境介质间传输、转化以及归趋起着重要的调控作用。传统的研究方法虽然可以在实验室模拟并进而描述污染物环境界面过程,但是不能揭示界面反应机制,限制了对污染物环境界面行为的认识。近二十年来,各种谱学技术(例如X射线吸收精细结构和傅里叶红外光谱等)应用于环境界面反应的研究,推动了这一领域研究的发展,特别是在分子水平研究污染物的环境界面过程。通过现代光/波谱技术原位分析,可以实时获取界面反应的定量与结构信息,从而更准确地判断反应机制,极大促进了对污染物在多介质环境界面迁移转化规律的认识。本文将在概述环境界面化学反应的基础上,针对无机离子在环境界面的反应过程,重点介绍几种关键光/波谱技术(X射线吸收精细结构光谱、傅里叶红外光谱、拉曼光谱、核磁共振谱和穆斯堡尔谱等)在环境界面化学研究中的应用,并展望其在环境界面过程研究中的应用前景。  相似文献   

15.
胡惠媛  朱虹 《化学进展》2012,24(11):2212
壳聚糖的结构中含有大量的—NH2和—OH,因此其对重金属离子有优良的吸附作用。但是作为天然高分子物质,壳聚糖的吸附性能又受到其自身物理形态、原料来源、脱乙酰度及体系pH值的影响,因此,对其进行物理和化学改性是提高壳聚糖吸附性能、扩大应用范围的必要手段。本文综述了壳聚糖的改性方法及其衍生物对重金属离子吸附作用的研究进展,并对其在重金属污染废水处理方面的前景作了展望。  相似文献   

16.
The activity and kinetic stability of a keratinolytic subtilisin-like protease from Bacillus sp. P45 was investigated in 100 mM Tris-HCl buffer (pH 8.0; control) and in buffer with addition of Ca(2+) or Mg(2+) (1-10 mM), at different temperatures. Addition of 3 mM Ca(2+) or 4 mM Mg(2+) resulted in a 26% increment on enzyme activity towards azocasein when compared to the control (100%; without added Ca(2+) or Mg(2+)) at 55 °C. Optimal temperature for activity in the control (55 °C) was similar with Mg(2+); however, temperature optimum was increased to 60 °C with 3 mM Ca(2+), displaying an enhancement of 42% in comparison to the control at 55 °C. Stability of protease P45 in control buffer and with Mg(2+) addition was assayed at 40-50 °C, and at 55-62 °C with Ca(2+) addition. Data were fitted to six kinetic inactivation models, and a first-order equation was accepted as the best model to describe the inactivation of protease P45 with and without metal ions. The kinetic and thermodynamic parameters obtained showed the crucial role of calcium ions for enzyme stability. As biocatalyst stability is fundamental for commercial/industrial purposes, the stabilising effect of calcium could be exploited aiming the application of protease P45 in protein hydrolysis.  相似文献   

17.
Using the hydrazone linker and the self‐assembly, functionalized Ag complexes with a helical structure showed a 2.96 Å distance between metal‐metal bonds, well‐aligned aromatic rings, and the strong affinity toward DNA.  相似文献   

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宫志龙  章竹君 《分析化学》1996,24(9):1007-1010
作者观察到Eu^3+、Tb^3+、Gd^3+、Al^3+、Ga^3+、In^3+、Zr^4+和Hf^4+的二元络合物在水溶液中能够与EDTA型的螯合树脂chelex100形成配位体-金属离子-chelex100的三元络合物,络合物的形成不但改变了它们的光谱性质,而且大大增强了其磷光或荧光强度。利用这一性质,本文制作了测定上述金属离子的流通式光学传感器。实验表明该传感器提高了测定的灵敏度与选择性。  相似文献   

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