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以5-溴水杨醛和4-苯基-3-氨基硫脲合成了一种新型希夫碱类阴离子比色探针,研究了该探针对常见阴离子的比色响应特性。结果表明,在DMSO体系中加入氟离子、乙酸根离子和磷酸二氢根离子后,探针的最大吸波长从352 nm红移到398 nm,肉眼可观察到溶液的颜色从淡黄色变成了黄色,而其它的阴离子如氯离子、溴离子和碘离子的加入基本不引起溶液紫外-可见吸收波长的任何变化。因此,这种探针可以用来识别氟离子、乙酸根离子和磷酸二氢根离子。 相似文献
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以3-异氰酸丙基三乙氧基硅烷和2, 4-二硝基苯肼为原料,制备了一种氨基脲衍生物阴离子受体R,其结构通过1H/13C NMR等方法表征。在纯DMSO体系下,受体R通过紫外-可见吸收光谱的变化及溶液颜色的显著差别对F-、Ac-和CN-离子表现出良好的识别能力。此外,通过向体系中加入30%的竞争溶剂H2O可以达到对CN-离子的单一识别效应。根据Benesi-Hidebrand方程,受体R单一识别氰根离子的络合常数为8.58 ? 103 L/mol,且检出限为1.47 uM,Job曲线分析证实受体与阴离子的结合比为1 : 1。利用1H NMR滴定实验及理论计算表明受体R与阴离子是以氢键形式相结合的识别机制,未发现脱质子过程。 相似文献
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介绍了锌酸盐镀锌液中氯离子、硫酸根离子、硝酸根离子、铬酸根离子、碳酸根离子等阴离子,以及油污、过量添加剂、添加剂分解产物等有机杂质的影响和去除方法.讨论了采用活性炭及铝粉处理有机杂质的方法,详细介绍了CK-778净化剂的使用方法. 相似文献
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Ion-selective electrodes of the coated-wire type were used in potentiometric titrations of polypropylene glycols, copolymers of ethylene oxide and propylene oxide and non-ionic surfactants based on oxyalkylated fatty alcohols and furfurylalcohol. The titration with a standard solution of sodium tetraphenylborate is based on precipitation of ternary compounds in the presence of bivalent metal ions; barium(II) salts are preferable. This compound is extractable to the membrane plasticizer; the electrode potential is than governed by the extraction principles. The signal-stabilization time during titrations depends on the length of the poly(oxypropylene) chain and thus, the results of manual titrations are more precise than those of automatic titrations. Moreover, the results indicate that an average of 6.2 oxypropylene units correspond to one tetraphenylborate ion, ie, 12.4 units per each barium(II) ion. For analysis of detergents or other samples of practical importance, the use of empirical titration equivalents is recommended. 相似文献
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ABSTRACT Two types of thiocarbamic-O-alkylesters, four bidentate ligands HL and one bis-bidentate ligand H2L, were used as extractants for heavy metal ions from aqueous solutions. Silver(I) was extracted as neutral complexes in a yield > 99 %. The underlying stoichiometry and the extraction constants are discussed. The extraction of silver&I) by the bis-bidentate ligand is significantly more effective than the extraction by the analogous bidentate compound. In a dioxane/water mixture neutral, cationic and anionic silver complexes were found by means of pAg and pH potentiometric titrations. The extraction behavior is discussed with regard to the calculated stability constants. 相似文献
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将2,4-二甲基-3-乙基吡咯与对-乙氧羰基苯甲醛在三氟乙酸的催化作用下发生缩合反应,用23,-二氯-5,6-二氰基-14,-苯醌(DDQ)氧化,并依次用N(Et)3和BF3.OEt2处理,得化合物(2),再将(2)在甲醇-氢氧化钠溶液中加热回流、水解,制备出中位取代苯甲酸基的硼-二吡咯亚甲基染料衍生物(1)。采用荧光光谱滴定方法研究了它的金属离子传感性能。结果表明,在甲醇溶液中,染料(1)显示出显著的对汞离子具有选择性的"开-关"型亲离子荧光团响应,可作为检测汞离子的荧光探针。另外,还初步探讨了荧光探针的检测机制。 相似文献
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设计合成1-(4-乙炔苯基)-3-(4-硝基苯)硫脲,聚合得到含硫脲聚苯乙炔poly(1)。通过一系列阴离子的正四丁基铵盐评价其阴离子识别性能。加入CH3CO-2,C6H5CO-2和F-后,poly(1)的DMF溶液颜色由黄色变成橙红色;而加入Cl-,HSO-4,Br-和NO-3后,溶液颜色不变,结果表明poly(1)显示阴离子识别能力。1H NMR滴定表明硫脲和阴离子的氢键引发poly(1)的比色响应。poly(1)对阴离子的结合能力大小顺序排列为:C6H5COO-≈CH3COO-≈F-Cl-≈HSO-4≈Br-≈NO-3,其阴离子选择性与阴离子的碱性相关。 相似文献
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Soosai Devaraj Veeramuthu Stalin Elanchezhian Muthusamy Kandaswamy 《Inorganic chemistry communications》2011,14(10):1596-1601
The new ferrocene based receptors N-[4-ferrocenyl-2-methyl-4-oxobut-1-enyl]-N′-phenylthiourea (1), N-[4-ferrocenyl-2-methyl-4-oxobut-1-enyl]-N′-[4-nitrophenyl]thiourea (2) were synthesized and characterized. Fluorescence titrations of receptors 1 and 2 with various transition metal ions showed selective response to Cu2+ ions and the emission intensities quenched significantly. Electrochemical titrations with anions revealed that receptors 1 and 2 sensed the F− anion in high selectivity with a cathodic shift of 100 mV. 相似文献
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The synthesis of polyacrylonitrile‐block‐poly(ethylene oxide) (PAN‐b‐PEO) diblock copolymers is conducted by sequential initiation and Ce(IV) redox polymerization using amino‐alcohol as the parent compound. In the first step, amino‐alcohol potassium with a protected amine group initiates the polymerization of ethylene oxide (EO) to yield poly(ethylene oxide) (PEO) with an amine end group (PEO‐NH2), which is used to synthesize a PAN‐b‐PEO diblock copolymer with Ce(IV) that takes place in the redox initiation system. A PAN‐poly(ethylene glycol)‐PAN (PAN‐PEG‐PAN) triblock copolymer is prepared by the same redox system consisting of ceric ions and PEG in an aqueous medium. The structure of the copolymer is characterized in detail by GPC, IR, 1H‐NMR, DSC, and X‐ray diffraction. The propagation of the PAN chain is dependent on the molecular weight and concentration of the PEO prepolymer. The crystallization of the PAN and PEO block is discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1753–1759, 2003 相似文献
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采用缓慢蒸发溶剂的方法,在去离子水溶剂中合成了双金属Co(Ⅱ)和Ni(Ⅱ)单核配合物[Co0.78Ni0.22(py)3(H2O)3](1,5-nds)(1,5-nds=1,5-萘二磺酸根离子,py=吡啶)。利用X射线单晶衍射以及红外光谱等表征手段确定了其结构和组成。该配合物属于单斜晶系,空间群为C2/c。该配合物为单核配合物,中心离子为双金属Co(Ⅱ)和Ni(Ⅱ)。中心离子与三个吡啶和三个水分子配位。1,5-萘二磺酸根离子没有与中心离子配位,只起到平衡电荷的作用。 相似文献
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将Mn(Ⅱ)离子、有机配体L(L=1,6-二苯基-2,5-双(2-甲基吡啶基)-2,5-二重氮己烷)和氰基化合物cis-FeⅡ(bpy)2(CN)2·3H2O(bpy=2,2′-联吡啶)在NH4PF6存在下制备一个四元环异核氰桥化合物即标题化合物,并对其结构进行表征。重金属离子对标题化合物的荧光响应研究表明,标题化合物对Cu(Ⅱ)和Fe(Ⅲ)有很好的选择性。随着金属离子Cu(Ⅱ)和Fe(Ⅲ)的加入,标题化合物的荧光强度逐渐降低至基本消失。随着金属离子Pb(Ⅱ)和Fe(Ⅱ)的加入,标题化合物的荧光强度逐渐降低,当金属离子加到一定浓度,标题化合物的荧光强度不随金属离子的变化而变化。对于Co(Ⅱ)、Cr(Ⅲ)、Mn(Ⅱ)、Cd(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)等离子,随着金属离子的加入标题化合物的荧光强度改变甚微或不改变。 相似文献