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Two novel supramolecular aggregations possessing column structures have been prepared from double-armed benzo-15-crown-5 ether (2) and its complex with potassium ion, respectively. Their molecular assembly behavior has been evaluated by calorimetry, 1H NMR, X-ray crystallography and STM images, revealing that the molecular assembly behavior of 2 in the solid state can be controlled by the stepwise sandwiching complexation with the cation. 相似文献
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Oxymethylcrowned spirobenzopyran 1 and pyrenylspirobenzopyran 2 were synthesized, and fluorescence emission of their corresponding merocyanine form was examined in the presence of metal ions. For 2, fluorescence emission derived from the pyrene moiety was completely quenched by photoinduced electron transfer (PET) of the nitrogen atom when the merocyanine form was not produced, namely, without metal ions. However, when 2 was converted to the merocyanine form by the complexation of its crown ether with a metal ion, fluorescence resonance energy transfer (FRET) from the pyrene to the merocyanine moieties took place to produce fluorescence emission. This result demonstrates that the spirobenzopyran isomerization can function as a fluorescence emission switch. Fluorescence quantum yield measurement for 1 and 2 showed that fluorescence emission depends on the binding metal ion in which the fluorescence quantum yield generally increased with the increase of metal ion radius. 相似文献
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在萃取研究过程中,合成了10种由四溴(或碘)合铟(Ⅲ)配阴离子与苯并-15-冠-5或二苯并-18-冠-6合钾(或钠)配阳离子相结合所形成的新型固体配合物。经元素分析、红外光谱及差热-热重等方法对配合物进行了表征。通过与相应的冠醚碱金属苦味酸盐配合物结构性质的对比,较合理地解释了这两类萃取体系之间存在的某些差别。 相似文献
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采用苯并15冠5、没食子酸甲酯以及1-溴十一烯等物质为原料,合成超分子化合物2-(1-甲基羟甲基)-[1,4,7,10,13-苯并15冠5]-3,4,5-三[4-(10-十一烯-1-羰基)苄氧基]苯甲酸酯.然后用紫外光接枝法将其接枝到聚丙烯腈(PAN)微孔膜表面,构筑具有离子传输功能的离子传输复合膜,接枝量为3.025 mg/cm2.通过ATR,XPS,SEM以及AFM等手段对离子传输膜的结构性能进行表征.结果表明,这种超分子化合物在PAN膜的表面自组装成柱状通道,并形成致密皮层.采用自行设计的膜运输装置对膜的离子识别和运输功能进行评测.通过与非功能材料(丙烯酸)接枝膜的对比,可以认为本文制备的离子识别膜可以选择性识别和运输碱金属阳离子,其运输能力顺序为Na+>K+>Li+. 相似文献
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Abstract Molecular structures of the RbSCN complexes with N-(4′-hydroxy-3′,5′-diisopropylbenzyl)-monoaza-15-crown-5 ether (2-RbSCN) and N-(4′-hydroxy-3′,5′-di-tert-butylbenzyl)-monoaza-15-crown-5 ether (3-RbSCN) are reported. Crystal data (2-RbSCN) C24H39N2O5SRb, M = 553.11, monoclinic, space group P21, a = 9.835(4), b = 15.44(3), c = 18.563(6) Å, β = 99.58 (4), U = 2779(4) Å3, Z = 4, Dc = 1.322 gcm?3, v = 18.87 cm?1, R = 0.047, Rw = 0.049 for the 5339 independent reflections (of 5712 measured reflections) and 590 parameters. (3-RbSCN) C52H86N4 O10S2Rb2, M = 1162.32, triclinic, space group P21, a = 9.917(2), b = 24.644(6), c = 12.572(3), α = 89.38(2), γ = 96.13(2), γ = 89.34(2) Å, U = 3054(1) Å3, Z = 2, Dc = 1.264 g cm?3, μ = 17.20 cm?1, R = 0.051, R = 0.053 for the 6864 independent reflections (of 7201 measured reflections) and 316 parameters. The molecular structures of the RbSCN complexes with a series of N-(4-hydroxy-3′,5′-dialkylbenzyl)-monoaza-15-crown-5 ethers (1, 2 and 3) were systematically changed depending upon the size of the R groups at positions 3′ and 5′ in the side arm; 1 (R=Me), a polymer-like (1:1)n complex; 2 (R = i-Pr), a mixture of 1:1 complex and polymer-like (1:1)n complex; 3 (R = t-Bu), a dimeric 1:1 complex. 相似文献
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Júlia KertészBalázs Bognár Attila KormosIldikó Móczár Péter BaranyaiMiklós Kubinyi Tamás KálaiKálmán Hideg Péter Huszthy 《Tetrahedron》2011,67(46):8860-8864
Double (spin and fluorescence) labeled pyrroline derivatives of crown ethers containing an acridone or an acridine fluorophore unit (1 and 2) and their diamagnetic analogues (3 and 4) were synthesized. Their fluorescent behavior as well as their complexation properties toward selected metal ions (Na+, K+, Mg2+, Ca2+, Zn2+) were examined. 相似文献
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Brian D. Wagner Shannon J. Fitzpatrick Gregory J. McManus 《Journal of inclusion phenomena and macrocyclic chemistry》2003,47(3-4):187-192
The fluorescence intensity of 7-methoxycoumarin (7MC) in aqueoussolution is found to significantly decrease upon addition of variouscyclodextrins. This observed phenomenon is described asfluorescence suppression, to distinguish it from fluorescencereduction via bimolecular quenching. The decrease in fluorescenceof 7MC is proposed to be the result of the formation of ahost–guest inclusion complex with cyclodextrin. Since 7MC isa polarity-sensitive fluorophore, which is less fluorescent ina nonpolar environment, its fluorescence decreases uponinclusion into the relatively nonpolar internal cavity of thecyclodextrin. The same equation used for extracting the associationconstant in the case of 1 : 1 host–guest inclusion-induced fluorescenceenhancement is shown to be applicable to the case of fluorescencesuppression. In the case of β-cyclodextrin, the degree of fluorescencesuppression, as well as the value of the binding constant for formationof the inclusion complex, are found to be unaffected by modificationof the cyclodextrin rims, suggesting that the molecule iscompletely included within the β-cyclodextrin cavity. In the case ofγ-cyclodextrin, the degree of fluorescence suppression, butnot the value of the binding constant, is found to be significantlyaffected by modification of the cyclodextrin rims, suggesting thatthe molecule is experiencing a less polar environment in the modifiedγ-cyclodextrin cavity. The binding constant is three timeslarger in β- as compared to γ-cyclodextrin, indicatinga much better size match in the smaller β-cyclodextrin cavity. 相似文献
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XIONG Guo-Xiang ZHOU Qing-Fu XU Hui-JunInstitute of Photographic Chemistry Chinese Academy of Sciences Beijing China 《中国化学》1996,14(5):447-453
4',5'-Dibromo-o-xylyl-17-crown-5 ether (2BrB17C5) was synthesized,starting from 1,2-dibromo-4,5-bis(bromomethyl)-benzene and tetraethylene glycol,and was characterized by 1H NMR,MS and elemental analysis.Pale yellow prismatic single crystal obtained from anhydrous ethanol was investigated by X-ray structural analysis.The complexation properties toward alkali metal ions were examined using the solvent extraction method and UV absorption spectroscopy.The crown ether was found to be conformationally deformed and oblate-like and is highly selective for lithium ion. 相似文献
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Yuji Suzaki 《Journal of organometallic chemistry》2010,695(23):2512-213
Cyclization reactions of Fe{C5H4OCH2(CH2OCH2)nCH2OTs}2 (n = 1, 2) with C6H4-1,2-(OH)2, C6H4-1,3-(OH)2, and Fe(C5H4OAc)2 under basic conditions yield the corresponding macrocyclic 1,1′-ferrocenophanes. The ferrocenophane having a pyrido-crown ether structure was also synthesized. These ferrocenophanes were characterized by X-ray crystallography and NMR spectroscopy. Cyclic voltammograms of the ferrocenophanes exhibited reversible redox peaks assigned to the oxidation and reduction of the ferrocene unit. The macrocyclic pyrido-containing ferrocenophane forms pseudorotaxane with [NH2{(CH2)9Me}2]BARF (BARF = B{C6H3-3,5-(CF3)2}4) in CDCl3. 相似文献
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吲跺啉螺吡喃是一类重要的有机光致变色化合物,当被紫外光和可见光照射时可逆地异构化.一系列的研究表明它在非银材料、非线性光学器件以及高分辨率的信息存贮和再现等诸方面的应用价值[1].90年代以来,Inouye[2,3],Kimura[4-6]和吴成泰等[7-9]曾将冠醚结构单元引入螺吡喃,研究了对碱金属离子的识别作用及其由此诱导含冠醚螺吡喃化合物的异构化现象.由于冠醚化合物对金属离子具有特定的络合作用,当在含冠醚螺吡喃化合物中加入某些金属离子时,能诱发螺吡喃结构的异构化,从而强烈地影响异构化平衡,… 相似文献
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冠醚修饰的固体支撑双层类脂膜的形成及性能研究 总被引:3,自引:1,他引:3
用饱和了胆固醇和饰用冠醚的角鲨烷/氯仿溶液作成膜液,制备了冠醚修饰的固体支撑双层类脂分子膜。重点考察了成膜物种及技术对膜稳定性及电特生影响。其膜电势随接触水相中的变化呈现Nernst响应,线性范围10^-4-10^-1mol/L。 相似文献
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The effects of alkali metal complexation on the fluorescence properties of two crown ethers (a podand and a coronand) were investigated. Metal ion binding leads to changes in fluorescence intensity along with slight shifts in the emission maxima. This is attributed to a rigidization of the fluorophore and an interaction of the metal ion with non-bonding electrons of the crown ethers. The effects on the spectra are more pronounced in fluorescence than in absorption.Fluorescence titration with metal ions provides a simple and sensitive means for the determination of complexation constants, which were found to be highly dependent upon the water content of the methanol solution. Halide counterions, in particular iodide, act as dynamic fluorescence quenchers withStern-Volmer constants that are different for the sodium and potassium complexes, respectively.
Die Effekte der Komplexierung von Alkalimetallionen auf die Fluoreszenzeigenschaften von Kronenethern
Zusammenfassung Die Effekte der Komplexierung von Alkalimetallionen auf die Fluoreszenzeigenschaften zweier Kronenether (eines Podanden und eines Coronanden) wurden untersucht. Die Bindung des Metallions fürt zu Veränderungen in der Fluoreszenzintensität und zu Verschiebungen in den Emissionsmaxima. Dies wird einer gesteigerten Starrheit des Fluorophors und einer Wechselwirkung des Metallions mit nichtbindenden Elektronen des Kronenethers zugeschrieben. Die Auswirkungen auf die Spektren sind in der Fluoreszenz ausgeprägter als in der Absorption.Fluoreszenztitrationen mit Metallionen bieten eine einfache und empfindliche Möglichkeit zur Bestimmung von Komplexkonstanten, welche stark vom Wassergehalt der methanolischen Lösung abhängig befunden werden. Halogenidgegenionen, insbesonders Iodid, wirken als dynamische Fluoreszenzlöscher und weisenStern-Volmer-Konstanten auf, welche für die Natrium- bzw. Kalium-Komplexe verschieden sind.相似文献
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Chiara Dall'asta Gianluigi Ingletto Roberto Corradini Gianni Galaverna Rosangela Marchelli 《Journal of inclusion phenomena and macrocyclic chemistry》2003,45(3-4):257-263
Cyclodextrins have been used as fluorescence enhancers in HPLC to improve thedetection limits of aflatoxins, cancerogens which can be found in severalfoodstuffs. In this work, a screening of several cyclodextrins has been performedin order to find the factors affecting the fluorescence enhancement. Evidence for formationof a 1 : 1 AF-CD inclusion complex has been achieved by titration and competitiveexperiments with adamantanecarboxylic acid and by fluorescence quenching by KI.Stability constants of the AF-CD complexes were evaluated. 相似文献
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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
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A conductance study of the interaction between ammonium ion and 18‐Crown‐6 (18C6), dicyclohexano‐18‐crown‐6 (DC18C6), ditertbutyl‐dicyclohexano‐18‐crown‐6 (t‐bu)2DC18C6, diaza‐15‐crown‐5 (DA15C5), dibenzo‐21‐crown‐7 (DB21C7) and N‐Phenylaza‐15‐crown‐5 (NPA15C5) in acetonitril‐di‐methylsulfoxide mixture was carried out at various temperatures. The formation constants of the resultant 1:1 complexes were determined from the molar conductance‐mole ratio data and found to vary in the order of DA15C5 > DC18C6 > 18C6 > (t‐bu)2DC18C6 > DB21C7 > NPA15C5. The enthalpy and entropy of the complexation reactions were determined from the temperature dependence of the formation constants. 相似文献
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多胺修饰β-环糊精对铝-铁试剂荧光体系的增敏作用 总被引:1,自引:0,他引:1
研究了β-环糊精(1)、单-[6-乙二胺-6-脱氧]-β-环糊精(2)、单-[6-(二乙烯三胺)-6-脱氧]-β-环糊精(3)和单-[6-(三乙烯四胺)-6-脱氧]-β-环糊精(4)对铝-铁试剂荧光体系的增敏作用。实验结果表明:加入β-环糊精及其衍生物后体系的荧光强度均增强,增敏率为4>3>2>1,其中4给出最大的荧光增敏率。研究了pH值在3.0-7.5之间酸度对主体化合物增敏能力的影响,发现体系的pH值对β-环糊精的增敏率影响较小,而随着体系酸性的增强,多胺修饰β-环糊精的增敏作用显著增强。探讨了修饰环糊精引入边臂的长度和主-客体间的尺寸适合等因素对铝-铁试剂体系荧光增敏率的影响。 相似文献
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The structures of 18-crown-6 (18C6) complexes with K+ and Rb+ in methanolic solutions have been studied by X-ray absorption fine structure (XAFS) at the Br K-edge as well as at the K
and Rb K-edges. The XAFS spectrum at the K or Rb K-edge has indicated that either Br− or solvent (methanol) molecules are present in the first coordination shell of K+ or Rb+ complexed by 18C6. However, the spectra obtained at the Br-K edge have strongly suggested that the alkali cations do not
exist in the vicinity of Br−, indicating that no direct ion-pairing occurs between the 18C6 complex and Br−. The 18C6-K+ complex maintains D
3d symmetry even in methanol, and two methanol molecules coordinate the cation possibly from above and below the crown plane.
In contrast, the corresponding Rb+ complex possibly forms an umbrella-shaped complex, in which Rb+ is situated slightly off the crown plane and three solvent molecules bind With the cation. 相似文献
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FluorescenceEnhancementofSamarium-Thenoyl-trifluoroacetone-CetyltrimethylammoniumBromide-TritonX-100byScandiumZHUGui-yun,LIUP... 相似文献