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1.
设计合成了一种基于久洛尼定的苯腙型化学传感器C1,应用紫外-可见吸收光谱研究了该传感器分子与阴离子的相互作用。结果表明:传感器分子C1在乙腈中可以选择性地识别氟离子,氟离子加入可使吸收光谱发生50 nm红移,溶液颜色由黄色变为紫色;其他阴离子Cl~-,Br~-,I~-,ClO_4~-,HSO_4~-,NO_3~-,AcO~-和H_2PO_4~-的加入不会对吸收光谱产生明显的影响,可见所设计的传感器分子C1可作为高选择性裸眼识别氟离子的比色传感试剂。  相似文献   

2.
已知氟离子和磷酸根能加快锐钛矿和P25 TiO2光催化降解苯酚等有机物,但作用机理仍存在争议.合成了不含无机阴离子的锐钛矿,并在其表面沉积0.52 wt% Pt(Pt/TiO2).在初始pH 5.2的水溶液中,99%的氟离子和磷酸根分别为F-和H2PO4-.加入0.1~30 mmol/L阴离子,苯酚的光催化降解速率常数(kobs)都增大,证实了氟离子和磷酸根均具有正效应.有趣的是,kobs增加倍数均与阴离子吸附量呈线性关系,其中氟离子的斜率大于磷酸根,而Pt/TiO2的斜率大于TiO2.这表明阴离子的正效应源于吸附于固体表面的阴离子,并且氟离子的活性大于磷酸根.(光)电化学测试表明,氟离子和磷酸根分别抑制和促进O2还原,但它们都促进苯酚氧化.此外,氟离子和磷酸根分别使TiO2平带电位移动-159 mV和89 mV.前者有利于TiO2价带与苯酚发生轨道重叠,后者有利于TiO2导带分别与O2发生轨道重叠,进而加快界面电荷转移.由于阴离子广泛存在,该结果将有助于半导体光催化的机理研究及其环境应用.  相似文献   

3.
离子液体型表面活性剂研究   总被引:2,自引:0,他引:2  
易封萍  李积宗  陈斌 《化学学报》2008,66(2):239-244
以1-甲基咪唑为原料, 制备了6个常规离子液体: 1-正丁基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[bmim][BF4]及[bmim][PF6])、1-正己基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[hmim][BF4]及[hmim][PF6])、1-正十六烷基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[C16mim][BF4]及[C16mim][PF6])和4个功能化离子液体: 1-(2-羟乙基)-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[2-hemim][BF4]及[2-hemim][PF6])、1-乙氧羰基甲基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[eocmmim][BF4]及[eocmmim][PF6]). 研究了这两类离子液体的一些物理性能, 旨在挖掘离子液体在香料香精化妆品工业中的应用价值. 分别检测了它们与一般溶剂的互溶性, 并测定了它们的表面张力和发泡性能, 实验结果表明, 仅[C16mim][BF4]和[C16mim][PF6]具有发泡性能, 发泡力分别为68和120 mm.  相似文献   

4.
秦海娟  杨洗  何永炳  卿光焱  刘成金 《化学学报》2006,64(22):2271-2274
合成了一种带有荧光基团蒽的酰胺型双冠醚阴离子受体3. 用荧光光谱、紫外-可见吸收光谱及核磁共振氢谱研究了其与F, Cl, Br, I, H2PO4, AcO离子的相互作用, 结果表明3只对F具有很好的选择性识别能力, 并形成配合比为1∶2的络合物, 通过荧光发射强度计算出主体3与F间的相互作用时的结合常数.  相似文献   

5.
以氯化1,7-二(2-苯并咪唑)-庚烷(SBHt)为客体,八元瓜环(Q[8])为主体,利用1H NMR技术、动态光散射实验、荧光发射光谱、紫外吸收光谱详细探索了其在溶液中的相互作用、超分子自组装过程及作用模式. 首先考察了八元瓜环对客体pKa的影响,确定了研究主客体相互作用的条件,并详细探索了主客体的超分子自组装过程及作用模式. 主体Q[8]与客体SBHt相互作用的1H NMR谱图表明,主客体相互作用自组装形成1:1超分子聚合物. 这一推断得到动态光散射实验、紫外吸收光谱、荧光发射光谱测定结果的证实,并通过紫外吸收光谱、荧光发射光谱确定其表观稳定常数分别为2.79×105 L/mol及2.48×105 L/mol. 而晶体结构测定表明主体Q[8]与客体SBHt自组装形成1:2的简单包结配合物. 导致Q[8]与SBHt在溶液中和固体状态下形成不同自组装结构可能源于瓜环的外壁作用与包结作用竞争所致.  相似文献   

6.
苏木素与DNA相互作用的光谱研究   总被引:3,自引:0,他引:3  
以吖啶橙(AO)作探针研究了苏木素(HE)与DNA的相互作用. 吸收光谱和荧光光谱研究表明, 苏木素与DNA发生作用生成了复合物. 其结合比nHEnDNA=3∶1, 22 ℃时苏木素与DNA的结合常数K=5.96×104 L/mol. 同时研究了酸度、盐效应和温度等对苏木素与DNA相互作用的影响以及它们之间的作用方式, 确定了苏木素与鲱鱼精DNA之间为混合作用方式.  相似文献   

7.
制备了2,6-二苯甲酰胺吡啶盐酸盐(3), 利用荧光发射光谱和紫外可见吸收光谱研究了3对氟离子的选择性识别作用,氟离子可使3发生明显的荧光淬灭作用,并且溶液颜色也由无色变成黄绿色,实现了裸眼识别。利用Job法测定3与氟离子的结合比,发现主体化合物与氟离子形成1:1型络合物。采用Gaussian03软件模拟了3以及3与氟离子形成络合物的分子结构,发现3与氟离子通过(N-H) + ?F-和N-H ?F-两种氢键作用结合, 其中(N-H) + ?F-的氢键作用能力更强,增强了3对氟离子的识别能力。  相似文献   

8.
以3-氧杂多氟烷烃磺酰氟XCF2OCF2CF2SO2F为原料,顺序经磺酸钾、磺酸、磺酸酐再裂解制得了全氟烷基3-氧杂全氟戊烷磺酸酯XCF2OCF2CF2SO3CF2CF2OCF2X(1)(X=ICF2,1a;X=ClCF2,1b;X=HCF2,1c;X=Cl2CF,1d),1极易和多种亲核试剂反应,其中催化量的卤离子和硫氰根离子即可定量地将1分解成相应的磺酸氟和酸氟。  相似文献   

9.
设计合成了新型的席夫碱探针2-羟基-1-萘甲醛缩-2-吡啶甲酰腙(L),通过红外、质谱、核磁氢谱和碳谱,对其结构予以了表征。利用紫外-可见吸收光谱研究了探针分子L对不同阴离子(F~-,Cl~-,Br~-,I~-,NO_3~-,CH_3COO~-,HSO_4~-,H_2PO_4~-,ClO_4~-)的识别性能,结果显示在乙腈体系中探针L对F~-具有单一选择性识别作用,可以实现对氟离子的裸眼识别。由Benesi-Hildebrand方程(采用紫外滴定光谱计算)显示,探针L与F~-以1:2的化学计量比稳定结合,二者的结合比为1.37×10~9(mol/L)~(-2),检测限为0.319μmol/L。采用~1H-NM R滴定实验研究了探针分子与氟离子的结合机理,结果表明探针L与氟离子先形成氢键然后发生去质子化过程,分子内电荷转移(ICT)是导致探针分子L和F~-作用后紫外-可见吸收光谱红移及颜色变深的主要原因。  相似文献   

10.
以双三氟甲烷磺酰亚胺离子([NTf2]-)为阴离子,合成阳离子烷基取代不同(C1、C2和C4)的硅烷基咪唑离子液体,以其为固定相制备气相色谱填充柱。 硅烷基咪唑离子液体为强极性固定相;阳离子结构影响固定相的热稳定性、极性和分离性能。 在这些离子液体固定相中,1-丁基-3-[(3-三甲氧基硅基)-丙基]咪唑双三氟甲烷磺酰亚胺([PBIM]NTf2)对Grob试剂分离性能较好。 利用溶剂化作用参数模型,评价[PBIM]NTf2固定相特性,研究固定相-组分分子之间相互作用机制;同时考察[PBIM]NTf2色谱柱对不同类型化合物的分离性能。 结果表明,[PBIM]NTf2固定相主要作用力是氢键碱性和偶极作用,对烷烃、醇、酯和胺等不同类型的样品组分表现出良好的分离能力。  相似文献   

11.
Novel colorimetric receptors 1-[(2-hydroxy-5-bromo-benzylidene)-amino]-anthraquinone, 1-[(2-hydroxy-5-methyl-benzylidene)-amino]-anthraquinone, and 1-[(2-hydroxy-5-nitro-benzylidene)-amino]-anthraquinone have been synthesized as fluoride ion sensors. A color change was observed visually (naked-eye) upon addition of fluoride ions in organic solvents to solutions of the receptors.  相似文献   

12.
苯甲酰氨基脲的合成及其阴离子识别   总被引:1,自引:0,他引:1  
聂丽  李爱芳  江云宝 《化学学报》2009,67(6):564-568
设计合成了N-(取代苯甲酰氨基)脲衍生物(取代基=p-OC2H5, H, p-Cl) 1~3, 应用吸收光谱法考察了受体分子与阴离子如 , F-, 等的相互作用, 考察了取代基对受体分子与阴离子亲合力和结合选择性的调控或改善能力. 结果表明, 该类受体分子与阴离子通过氢键形成阴离子配合物, 乙腈中受体分子1对F-表现出极高的响应选择性. Job作图法表明1与F-的结合计量比为1∶1, 1H NMR滴定结果为受体分子与阴离子间的氢键作用本质提供了直接证据, 初步探讨了F-响应选择性的原因.  相似文献   

13.
Novel colorimetric receptors for fluoride ion sensing containing anthraquinone as a chromogenic signaling unit and imidazo-2,2'-bithiophene binding sites are reported. Well-defined color change was observed upon addition of fluoride ions to acetonitrile solutions of receptors 2. Compounds 2a-c, deprotonated after fluoride ion addition, were studied as metal ion chemosensors in the presence of Zn(II), Hg(II), and Cu(II) in acetonitrile solutions, especially compound 2a which displayed a marked change from pink to yellow-gold colors upon complexation.  相似文献   

14.
Mahapatra AK  Manna SK  Sahoo P 《Talanta》2011,85(5):2673-2680
Five new chromogenic tripodal receptors (2a-e) containing electron withdrawing and donating groups appended to the azophenol moiety were synthesized, characterized, and their chromogenic behaviors toward various anions were investigated. These tripodal receptors showed a distinct color change only when treated with fluoride ions in CH3CN solution. Yet, other anions such as Cl, Br, I, NO3, ClO4, AcO, HSO4, and H2PO4 could not cause any color change. Thus, the receptors 2a-e can be used as a colorimetric chemosensor for the determination of fluoride ion. In addition, 1H NMR experiments were carried out to explore the nature of interaction between tripodal receptors and fluoride. Finally, analytical application and the use of test strip of the receptor 2b to detect fluoride was also reported.  相似文献   

15.
魏薇  张有明  魏太保 《中国化学》2008,26(10):1935-1938
本文设计并高产率合成了三种新型阴离子识别受体化合物,它们对F-的识别选择性较卤素其他阴离子的高。其对F-的识别性能通过紫外—可见光谱和核磁共振氢谱进行了检测,光谱数据表明,在DMSO溶液中受体与F-通过氢键相互作用形成1:1配合物。与以前我们报道的受体化合物相比,由于此类分子钳受体化合物具有更多的阴离子识别位点,因此具有更好地阴离子识别性能。  相似文献   

16.
A new series of bisthiosemicarbazone derivative receptors(1,2 and 3)have been synthesized by simple steps ingood yields.Their anion recognition properties were studied by UV-Vis and ~1H NMR spectroscopy.The resultshowed that the receptors 1,2 and 3 all had a better selectivity to F~-,CH_3COO~- and H_2PO_4~-,but no evidentbinding with Cl~-,Br~-,I~-,NO_3~- and HSO_4~-.Upon addition of the three anions to the receptors in DMSO,thesolution acquired a color change from colorless to dark yellow that can be observed by the naked-eyes,thus the re-ceptors can act as fluoride ion sensors even in the presence of other halide ions.The data showed that it was regularthat the three receptors had different binding ability with the three anions.For the same anion,the association con-stants followed the trend:receptor 1>3>2.The UV-Vis data indicates that a 1:1 stoichiometry complex isformed through hydrogen bonding interactions between compound 1,2 or 3 and anions.  相似文献   

17.
Two new colorimetric ligands (1-2) based on macrocyclic structures linked to three nitrophenylurea groups were synthesized in good yields, and their responses toward anions were studied. Anions with different shape, such as of fluoride, chloride, bromide, iodide, hydroxide, nitrate, perclhorate, cyanide, or dihydrogen phosphate in DMSO solution were added and only fluoride, hydroxide, cyanide, and dihydrogen phosphate enhances π delocalization and shifts the π-π transition in both ligands, leading to the generation of a pleasant orange color.The result is a balance between the acidity of the nitrophenylurea-NH donors modulated by the basic character of the anions. Stability constants for both receptors and the anions fluoride, hydroxide, cyanide, and dihydrogen phosphate were determined spectrophotometrically using the program HYSPEC. 1H NMR titrations experiments with fluoride were carried out.  相似文献   

18.
Multiple deuterium exchange between DMSO-d6 and amide hydrogens in two hexaamido cryptand fluoride receptors has been verified by 19F and 2H NMR and FAB mass spectral studies. Structural results for one of the complexes indicate a tricapped trigonal prism hydrogen bond coordination geometry around an encapsulated fluoride, with hydrogen bonds from fluoride to six amide and three phenyl hydrogens.  相似文献   

19.
Two artificial receptors, 1,2-bis-p-substituted phenyl-sulfonamido-4,5-bis-nitrobenzene, have been designed and synthesized. The interactions of these receptors with halide anions are determined by UV-vis and 1H NMR titration experiments. Results indicate that two receptors have strong sensitivity and selectivity for fluoride among halide anions. In addition, the visible color changes upon the addition of fluoride anion can make the receptors as convenient detection tools for fluoride anion.  相似文献   

20.
Jose DA  Kumar DK  Ganguly B  Das A 《Organic letters》2004,6(20):3445-3448
[structure: see text] Novel colorimetric receptors for selective fluoride ion sensing containing anthraquinone as chromogenic signaling subunit and urea (N,N' '-(9,10-dihydro-9,10-dioxo-1,2-anthracenediyl)bis[N'-phenyl])/thiourea (N,N' '-(9,10-dihydro-9,10-dihydro-9,10-dioxo-1,2-antrhacenediyl)bis[N-phenyl]) binding sites have been reported. These receptors have shown no affinity for other halide ions (Cl-, Br-, and I- ions). Well-defined color change in the visible region of the spectrum was observed upon addition of fluoride ion in DMSO/CH3CN solution of the receptors 1 and 2.  相似文献   

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