- Dual functional ionic liquids as plasticisers and antimicrobial agents for medical polymers
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Contamination of medical devices with bacteria such as Meticillin resistant Staphylococcus aureus (MRSA) is of great clinical concern. Poly(vinyl chloride) is widely used in the production of medical devices, such as catheters. The flexibility of catheter tubing is derived from the addition of plasticisers. Here, we report the design of two dual functional ionic liquids, 1-ethylpyridinium docusate and tributyl(2-hydroxyethyl)phosphonium docusate, which uniquely provide a plasticising effect, and exhibit antimicrobial and antibiofilm-forming activity to a range of antibiotic resistant bacteria. The plasticisation of poly(vinyl chloride) was tailored as a function of ionic liquid concentration. The effective antimicrobial behaviour of both ionic liquids originates from the chemical structure of the anion or cation and is not limited to the length of the alkyl chain on the anion/cation. The design approach adopted will be useful in developing ionic liquids as multi-functional additives for polymers.
- Choi, Seong Ying,Rodriguez, Hector,Mirjafari, Arsalan,Gilpin, Deirdre F.,McGrath, Stephanie,Malcolm, Karl R.,Tunney, Michael M.,Rogers, Robin D.,McNally, Tony
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- Study on thermophysical properties for aqueous solutions of ionic liquid N-ethyl-pyridine dicyanamide [C2py][DCA]
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The IL (ionic liquid) [C2py][DCA] (N-ethyl-pyridine dicyanamide) was prepared and confirmed by 1H NMR (1H nuclear magnetic resonance) spectroscopy, 13C NMR (13C nuclear magnetic resonance) spectroscopy. The values of density and surface tension of the IL [C2py][DCA] and its aqueous solutions with various molalities were determined at T = (288.15 to 318.15) K. The values of the molar volume for aqueous solutions of [C2py][DCA], V, were calculated and increase with the increase of temperature and molarity. On the basis of thermodynamics, a semi-empirical model-molar surface Gibbs free energy model of the ionic liquid solution was put forward. It can be used to predict the surface tension and the predicted values of the surface tension for aqueous [C2py][DCA] are all most the same with the corresponding experimental ones. In terms of the concept of the molar surface Gibbs free energy, a new E?tv?s equation is obtained. Each parameter of the new equation has a clear physical meaning, energy dimension and is more convenient to use.
- Xing, Nan Nan,Fan, Ben Han,Bu, Xiao Xue,Wei, Jie,Pan, Yi,Guan, Wei
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- Effective conversion sucrose into 5-hydroxymethylfurfural by tyrosine in [Emim]Br
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In this study, the synthesis of 5-hydroxymethylfurfural (5-HMF) from sucrose was carried out in ionic liquids 1-ethyl-3-methylimidazolium bromide ([Emim]Br) catalyzed by amino acids, and tyrosine displays the best activity. Under the optimal reaction conditions, 76.0% yield of 5-HMF from sucrose was obtained at 160 C for 4 h. The uniquely effective activity of tyrosine for sucrose conversion into 5-HMF in [Emim]Br is mainly attributed to its two types of active sites, free base NH2 and dissociated H+ sites. The former one plays a crucial role in the isomerization of glucose to fructose, and the latter one is active in the hydrolysis of sucrose into monosaccharides and dehydration of generated fructose to 5-HMF. Furthermore, the presence of acidic phenol group in tyrosine also has the synergic catalytic effect on sucrose conversion. In addition, with the use of tyrosine catalyst, other carbohydrates to form 5-HMF were also tested, and the effects of solvent, reaction temperature and reaction time on sucrose conversion into 5-HMF were investigated in detail. A possible mechanism for this catalytic process has been proposed.
- Su, Kunmei,Liu, Xin,Ding, Min,Yuan, Qiuju,Li, Zhenhuan,Cheng, Bowen
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- Direct catalytic conversion of glucose and cellulose
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Biomass product 5-hydroxymethylfurfural (5-HMF) can be used to synthesize a broad range of value added compounds currently derived from petroleum. Thus, the effective conversion of glucose or cellulose (the major components of biomass) into fuels and chemical commodities has been capturing increasing attention. Previous studies have been extensively focused on a two-step process for producing 5-HMF from glucose or cellulose, i.e., the isomerization of glucose into fructose and then the dehydration of fructose. We herein discovered that heterogeneous sulfonated poly(phenylene sulfide) (SPPS) containing strong Br?nsted acid sites is able to convert glucose and cellulose into 5-HMF with a high yield in ionic liquids (ILs). The optimal activity of glucose conversion to 5-HMF achieves a yield of 87.2% after 4 h reaction at 140 °C. For direct cellulose conversion, a 5-HMF yield of 68.2% can be achieved. The reaction mechanism over the SPPS catalyst in ILs was studied by DFT calculations, and the results indicated that the SO3H group of SPPS plays a crucial role in glucose conversion into 5-HMF, and it acts as a proton donor as a Br?nsted acid and functions as a proton acceptor as the conjugate base. Furthermore, the anions and cations of ILs together with SO3H-SPPS helped in stabilizing the reaction intermediates and transition states, which also resulted in glucose facile conversion into 5-HMF. The new catalyst system highlights new opportunities offered by optimizing the production of 5-HMF directly from glucose and cellulose.
- Li, Zhenhuan,Su, Kunmei,Ren, Jun,Yang, Dongjiang,Cheng, Bowen,Kim, Chan Kyung,Yao, Xiangdong
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- Bromobismuthates: Cation-induced structural diversity and Hirshfeld surface analysis of cation–anion contacts
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Reactions of [BiBr6]3? and bromide salts of various substituted pyridinium cations in excess of HBr result in a series of bromobismuthate anionic complexes of various geometry and nuclearity: [{BiBr4}n]n?, [Bi2Br9]3? and [Bi2Br10]4?. Hirshfeld surface analysis for 19 crystal structure was performed; impact of various X-Br contacts on the crystal structures is discussed.
- Adonin, Sergey A.,Gorokh, Igor D.,Novikov, Alexander S.,Samsonenko, Denis G.,Korolkov, Ilya V.,Sokolov, Maxim N.,Fedin, Vladimir P.
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- Thermochemistry of alkyl pyridinium bromide ionic liquids: Calorimetric measurements and calculations
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Two ionic liquids, 1-ethylpyridinium bromide (EPBr) and 1-propylpyridinium bromide (PPBr), were prepared and the structures were characterized by 1H NMR. The thermodynamic properties of EPBr and PPBr were studied with adiabatic calorimetry (AC) and thermogravimatric analysis (TG-DTG). The heat capacity was precisely measured in the temperature range from 78 to 410 K by means of a fully automated adiabatic calorimeter. For EPBr, the melting temperature, enthalpy, and entropy of solid-liquid phase transition were determined to be 391.31 ± 0.28 K, 12.77 ± 0.09 kJ · mol-1, and 32.63 ± 0.22 J-K-1-mol-1, respectively, and for PPBr they were 342.83 ± 0.69 K, 10.97 ± 0.05 kJ-mol-1, and 32.00 ± 0.10 J-K-1TnOn-1, respectively. The thermodynamic functions (HT° - H 298.15°) and (ST° - S298.15°) were derived from the heat capacity data in the experimental temperature range with an interval of 5 K. The thermostablility of the compounds was further studied by TGA measurements. The phase change behavior and thermodynamic properties were compared and estimated in a series of alkyl pyridinium bromide ionic liquids. Results indicate that EPBr has higher melting and decomposition temperature, as well as phase transition enthalpy and entropy but lower heat capacity than PPBr due to their different molecular structures.
- Tong, Bo,Liu, Qing-Shan,Tan, Zhi-Cheng,Welz-Biermann, Urs
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- Targeted Synthesis of Trimeric Organic-Bromoplumbate Hybrids That Display Intrinsic, Highly Stokes-Shifted, Broadband Emission
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Zero-dimensional (0D) hybrid organic-inorganic lead halides have been shown to display efficient broadband photoluminescence and are, therefore, of significant interest for artificial lighting applications. However, work that investigates the formability of the materials as a function of templating organic cation structure is rare. This severely limits our ability to rationally design new materials displaying specific structural and photophysical properties. With the goal of accessing rare 0D trimeric bromoplumbates, we have systematically varied templating N-alkylpyridinium cations and examined their impact upon inorganic lattice structure. Whereas comparatively short and flexible N-alkyl substituents (ethyl, 2-hydroxyethyl, and pentyl) yield one-dimensional (1D) inorganic chains, more rigid substituents (benzyl, acetamidyl, and cyanomethyl) afford hybrids composed of lead bromide face-sharing trimers (i.e., [Pb3Br12]6-). Of the rigid substituents studied, benzyl groups were found to enforce the highest level of distortion of the [PbBr6]4- octahedra that comprise their trimeric structures. Upon exposure to ultraviolet (UV) light, N-benzylpyridinium lead bromide (1)6[Pb3Br12] exhibits a broadband emission, centered at 571 nm, which spans from 400 to 800 nm. More specifically, it displays a large Stokes shift of ca. 1.39 eV and a full width at half-maximum of ca. 146 nm. This broadband emission decays with a comparatively long lifetime of 426 ns at room temperature, which increases to 5.8 μs at 77 K. The reduced size and dimensionality of its inorganic lattice also result in a photoluminescence quantum yield (of at least 10%) that is approximately one order of magnitude higher than that of its 1D congeners. Mechanistically, broadband emission in (1)6[Pb3Br12] is believed to originate from triplet excited state(s) obtained from excited-state structural reorganization of the [Pb3Br12]6- moiety.
- Febriansyah, Benny,Neo, Chong Shern Daniel,Giovanni, David,Srivastava, Shivani,Lekina, Yulia,Koh, Teck Ming,Li, Yongxin,Shen, Ze Xiang,Asta, Mark,Sum, Tze Chien,Mathews, Nripan,England, Jason
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- Density and surface tension of ionic liquids [Cnpy][NTf 2] (n = 2, 4, 5)
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Density and surface tension of the air- and water-stable hydrophobic ionic liquids N-alkylpyridinium bis(trifluoromethylsulfonyl)imide ([C npy][NTf2], n = 2, 4, 5) were measured in the temperature range T = (283.15 to 338.15) K. The melting temperatures of the samples were determined by differential scanning calorimetry (DSC). Decomposition temperatures are higher than 600 K as determined by thermogravimetric analysis (TG).
- Liu, Qing-Shan,Yang, Miao,Yan, Pei-Fang,Liu, Xiu-Mei,Tan, Zhi-Cheng,Welz-Biermann, Urs
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- Boosting activity of molecular oxygen by pyridinium-based photocatalysts for metal-free alcohol oxidation
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An eco-friendly and economical approach for the photocatalytic oxidation of organic inter-mediates by air under mild conditions is highly desirable in green and sustainable chemistry, where the photogeneration of active oxygen species plays a key role in improving conversion efficiency and selectivity. By using pyridinium derivatives as molecular mediators for electron transfer and energy transfer, the simultaneous activation of O2from air into superoxide radicals and singlet oxygen species can be achieved, and a photoinduced electron transfer catalytic system for the oxidation of alcohols has been developed. Thus, we have successfully simplified the complicated catalytic system into a single molecular catalyst without any additional noble metals and co-catalysts/additives. The current photocatalytic system shows high catalytic efficiency not only for aromatic alcohols but also for aliphatic alcohols that are generally difficult to undergo aerobic oxidation at room temperature under air atmosphere, representing an ideal photocatalytic platform for green and economical organic syntheses.
- Ma, Shuai,Cui, Jing-Wang,Rao, Cai-Hui,Jia, Meng-Ze,Chen, Yun-Rui,Zhang, Jie
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supporting information
p. 1337 - 1343
(2021/02/26)
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- ZIF-8-porous ionic liquids for the extraction of 2,2,3,3-tetrafluoro-1-propanol and water mixture
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The design of stable ionic liquids (ILs) has become crucial for efficient liquid-liquid extraction (LLE) of alcohol and water. Porous ionic liquids (PILs), as a special class of ILs, have attracted attention by virtue of their unique porous structure and IL characteristics. In this research, a series of zeolitic imidazolate framework-8 based porous ionic liquids (ZIF-8-PILs) were synthesized by simply mixing a solution of zeolitic imidazolate framework-8 (ZIF-8) and rationally designed ILs. The introduction of ZIF-8 resulted in a unique liquid porous structure and molecular sieve for ZIF-8-PILs. The improved extraction properties endowed ZIF-8/[Bpy][NTf2] with more efficiency for the separation of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water with 88.1% TFP extraction rate and steady reuse. The excellent extraction performance of ZIF-8-PILs is discussed in relation to their textural property and unique intermolecular interaction.
- Wang, Zenghui,Zhao, Pingping,Wu, Jimin,Gao, Jun,Zhang, Lianzheng,Xu, Dongmei
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supporting information
p. 8557 - 8562
(2021/05/26)
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- Enhanced activity and modified substrate-favoritism of Burkholderia cepacia lipase by the treatment with a pyridinium alkyl-PEG sulfate ionic liquid
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Three types of pyridinium salts, i.e., 1-ethylpyridin-1-ium cetyl-PEG10 sulfate (PYET), 1-butylpyridin-1-ium cetyl-PEG10 sulfate (PYBU), and 1-(3-methoxypropyl)pyridin-1-ium cetyl-PEG10 sulfate (PYMP), have been prepared and evaluated for their activation property of Burkholderia cepacia lipase by comparison to the control IL-coated enzymes, 1-butyl-2,3-dimethylimidazolium cetyl-PEG10 sulfate-coated lipase PS (IL1-PS). Among the tested pyridinium salt-coated lipases, the PYET-coated lipase PS (PYET-PS) exhibited the best results; the transesterification of 1-(pyridin-2-yl)ethanol, 1-(pyridin-3-yl)ethanol, 1-(pyridin-4-yl)ethanol, or 4-phenylbut-3-en-2-ol proceeded faster than those of the IL1-PS-catalyzed reaction while maintaining an excellent enantioselectivity (E > 200). This improved efficiency was found to be dependent on the increased Kcat value.
- Kadotani, Shiho,Nokami, Toshiki,Itoh, Toshiyuki
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p. 441 - 447
(2019/01/04)
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- Efficient ionic liquid synthesis method
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The invention relates to an efficient ionic liquid synthesis method. The efficient ionic liquid synthesis method is characterized in that an ultrasonic and microwave synergistic heating manner is adopted in an ionic liquid synthesis process. Through the new method adopting the ultrasonic and microwave synergistic heating manner to synthetize the ionic liquid, the reaction time is shortened, the reaction temperature is reduced, the energy consumption is reduced, and the obtained target product, namely the ionic liquid, is high in purity and less in by-product, and has a potential possibility of large scale popularization.
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Paragraph 0022; 0023; 0024
(2017/01/02)
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- Selective hydrogenation of phenol to cyclohexanone in water over PD@N-doped carbon derived from ionic-liquid precursors
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In this report, a kind of mesoporous N-doped carbon (CN-x) derived from N-containing ionic-liquid (IL) precursors were synthesized, and Pd@CN-x prepared by a simple ultrasound-assisted method showed higher catalytic activity for the selective hydrogenation of phenol and its derivatives under mild reaction conditions in water than commercial Pd@C and other common Pd heterogeneous catalysts. The catalytic activities of Pd@CN-x derived from different ILs were different, and further study into the influencing factors, including physical properties, N species of CN-x, and Pd status of Pd@CN-x, were performed. Being picky: N-Doped carbon (CN-x) derived from N-containing ionic-liquid precursors are used as Pd nanoparticle supports for the selective hydrogenation of phenol to cyclohexanone with high activity and selectivity under mild reaction conditions. The activities of the Pd@CN-x catalysts derived from a variety of ionic liquids are different, and studies on the physical properties, Pd status, and N species of the catalysts are performed.
- Xu, Xuan,Li, Haoran,Wang, Yong
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p. 3328 - 3332
(2015/04/16)
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- PROCESSES FOR PREPARING L-ALKYL-3-ALKYL-PYRIDINIUM BROMIDE AND USES THEREOF AS ADDITIVES IN ELECTROCHEMICAL CELLS
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The invention relates to the use of at least one l-alkyl-3- alkyl-pyridinium halide, in particular l-alkyl-3-methyl- pyridinium bromide, as an additive in bromine-generating electrochemical cells, such as zinc/bromine cells. Processes for preparing l-alkyl-3-methyl-pyridinium bromide and concentrated aqueous solutions comprising same for use as additives in the aforementioned cells, are also disclosed.
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Page/Page column 40
(2014/08/20)
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- Does alkyl chain length really matter? Structure-property relationships in thermochemistry of ionic liquids
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DSC was used for determination of reaction enthalpies of synthesis of ionic liquids [Cnmim][Cl]. A combination of DSC with quantum chemical calculations presents an indirect way to study thermodynamics of ionic liquids. The indirect procedure for vaporization enthalpy was validated with the direct experimental measurements by using thermogravimetry. First-principles calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the CBS-QB3 and G3 (MP2) theory. Experimental DSC data for homologous series of alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were collected from the literature. We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies are linearly dependant on the alkyl chain length. The thermochemical properties of ILs generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization seem to be very close to those for molecular compounds.
- Verevkin, Sergey P.,Zaitsau, Dzmitry H.,Emel'Yanenko, Vladimir N.,Ralys, Ricardas V.,Yermalayeu, Andrei V.,Schick, Christoph
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- Three different types of heterocycle of nitrogen-containing alkaline ionic liquids treatment of acid oil to remove naphthenic acids
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Ionic liquids had enormous potential for industrial use as environmental friendly chemicals. A green and effective deacidification method was found based on ionic liquids. N-alkylpyridinium bromide ([APy]Br), 1-alkyl-3- methylimidazolium bromide ([AMIm]Br) and 1-alkyl-3-methylimidazolium imidazolide ([AMIm]Im) were used to remove naphthenic acids from acid oil. The performance of deacidification followed the order [APy]Br [AMIm]Br [AMIm]Im. The stronger alkalinity of ionic liquids was, the higher deacidification would be. The growth of alkyl chain length was also beneficial to get high deacidification. The deacidification mechanism was that liquid clathrate could form due to interaction between the ionic liquids and π-bond in naphthenic acids through π-π interaction. When the reagent/oil ratio of [OMIm]Im (1-octyl-3-methylimidazolium imidazolide)/oil was 0.008, the deacidification rate could be reached 100%. The preliminary results reveal that the process consumes less energy, saves time and produces less pollution to environment.
- Duan, Jiyun,Sun, Yu,Shi, Li
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p. 180 - 185
(2013/07/26)
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- Alkylation process
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This invention relates to a process for the alkylation of aromatics by reacting an aromatic hydrocarbon with an olefin in the presence of an ionic liquid comprising (a) a compound of the formula Rn MX3-n wherein R is a C1-C6 alkyl radical, M is aluminium or gallium, X is a halogen atom and n is 0, 1 or 2 and, (b) a hydrocarbyl substituted imidazolium halide or a hydrocarbyl substituted pyridinium halide wherein at least one of the said hydrocarbyl substituents in the imidazolium halide is an alkyl group having 1-18 carbon atoms. The process allows ready separation of reaction products from the ionic liquid and improves selectivity to alkylated products.
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- Reaction Mechanism of Cathodic Crossed Coupling of Acetone with Unsaturated Compounds in Acidic Solution
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It was confirmed that the cathodic crossed coupling of acetone with unsaturated compounds in aqueous sulfuric acid could proceed smoothly, when the compounds which had radical-acceptable double bonds and were adsorbed on a mercury cathode were used.From this fact, it was concluded that the coupling occurs via the addition of a radical intermediate formed by the one-electron reduction of acetone to the double bonds on the cathode surface.Possibility of the addition of an anionic intermediate derived from acetone was excluded by no occurrence of the coupling of acetone with a polar acetylenic triple bond compound adsorbed on the cathode.
- Koizumi, Toshio,Fuchigami, Toshio,Kandeel, Zaghloul El-Shahat,Sato, Norio,Nonaka, Tsutomu
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p. 757 - 762
(2007/10/02)
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- The Interaction of Alkylammonium Salts with Synthetic Clays. A Fluorescence and Laser Excitation Study
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The interaction of surfactants with synthetic clays has been studied by a steady-state and a time-resolved fluorescence quenching method.The fluorescence quenching of 4-(1-pyrenyl)butyltrimethylammonium ion (PN(1+)) adsorbed on colloidal laponite clay by coadsorbed alkylpyridinium ions showed unusual behavior.Increasing the quencher concentration at first led to an efficient quenching of PN(1+) flourescence, but on increasing the quencher concentration further a reverse effect is observed, whereby the fluorescence started to recover, only to be followed by a smaller degree of quenching.The degree of recovery was strongly dependent on the chain length of the alkylpyridinium ions, the longer the chain length the larger the degree of recovery.PN(1+) fluorescence was also quenched by laponite clay itself or cupric ion in copper-clay, where cupric ion was constructed in the clay lattice.However, coadsorbed hexadecyltrimethylammonium ions (CTAB cations) dramatically reduced the quenching.The results can be explained in terms of the change of geometrical arrengement of PN(1+) adsorbed on clay.Quenching of PN(1+) fluorescence by dimethylaniline, nitrobenzene, and nitromethane in the CTAB-laponite system obeyed Poisson type kinetics, indicating that the adsorbents exist in the form of clusters or zones on the clay surface.
- Nakamura, T.,Thomas, J. K.
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p. 641 - 644
(2007/10/02)
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- Fluorescence Study of Pyrene and Naphthalene in Cyclodextrin-Amphiphile Complex Systems
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Amphiphilic molecules are shown to interact with pyrene-β-cyclodextrin (Py-β-CD) complexes leading to an extremely hydrophobic environment for pyrene (Py) in aqueous solution.The three-component systems give rise to a 1:1:1 complex of Py, β-CD, and the surfactant.The binding constant of Py and β-CD increases significantly in the presence of the surfactants, which suggests an improvement in the solubility of Py in aqueous β-CD systems.Larger binding constants of Py and β-CD were obtained in the presence of shorter chain amphiphiles between C4 and C16 surfactants.Fluorescence quenching of Py in Py-β-CD-pyridinium surfactants (CnPd(1+)x(1-)) systems obeyed first-order kinetics, which were independent of the concentration of CnPd(1+)X(1-) above a certain concentration, while the quenching rate constant was markedly affected by the chain length of the pyridinium surfactants.Smaller rate constants are obtained for longer chain surfactants.The observed kinetics are explained in terms of a 1:1:1 complex formation of Py, β-CD, and CnPd(1+)X(1-), and the chain-length-dependent rate constants are interpreted by assuming a "diffusion-controlled reaction within limited space".On the other hand, Stern-Volmer kinetics were observed for Py fluorescence quenching in the Py-β-CD-C16C2V(2+) (1-ethyl-1'-hexadecyl-4,4'-bipyridinium ion) system.This is ascribed to the long-range nature of the reaction in Py(S*1)-viologen group systems compared with that in Py(S*1)-pyridinium group systems.In the naphthalene-β-CD (N-β-CD) system, reduced association constants were observed in the presence of surfactants, which is markedly different from that observed in the Py-βCD system.A determination of the dynamic parameters of the equilibrium showed that the entry rate constant of naphthalene into β-CD was reduced in the presence of surfactants, while the exit rate constant was unchanged.The exit rate was appreciably reduced in the Py-β-CD system on addition of surfactants.Quenchers such as oxygen, nitromethane, copper(II) ion, thallium(I) ion, etc., which reside in the aqueous phase also quench excited Py in β-CD.The influence of CD with and without surfactant on the rate depends on the nature of the quenching reaction, and on the degree of screening by the host system on the guest molecule.It is demonstrated in the present study that the introduction of amphiphilic molecules into the Py-β-CD complex system improves the organization of the system and simplifies the reaction mechanism.The unique types of reaction kinetics observed are due to the selective organization of reactants in the CD system.
- Hashimoto, S.,Thomas, J. K.
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p. 4655 - 4662
(2007/10/02)
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