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Sample records for bf4 clo4 pf6

  1. The Properties of Binary Composite Ionic Liquids BMimBF4 and BMimPF6 Mixtures%BMimBF_4和BMimPF_6二元复合离子液体的特性

    Institute of Scientific and Technical Information of China (English)

    张冰; 陈松; 陈亮

    2012-01-01

    The kinematic viscosity, electrochemical window and electric conductivity of BMimBF4and BMimPF6 and their binary composite ionic liquids mixtures were studied. The results indicated that, physical and chemical properties of binary composite ionic liquids mixtures were changed by way of simply regulating volume of BMimBF4 and BMimPF6, which brought designing ionic liquids into full play and opened a new way for the application of "green solvent" - ionic liauids.%研究了BMimBF4、BMimPF6及其二者不同体积比复合离子液体的运动粘度、电化学窗口及电导率。结果表明,通过简单地调节BMimBF4和BMimPF6的复合体积比,可以改变BMimBF4和BMimPF6二元复合离子液体的物理化学性质,充分发挥离子液体的"可设计"性,为"绿色溶剂"离子液体的应用开辟了新的道路。

  2. The structural classification of the highly disordered crystal phases of [Nn][BF4], [Nn][PF6], [Pn][BF4], and [Pn][PF6] salts (Nn(+) = tetraalkylammonium and Pn(+) = tetraalkylphosphonium).

    Science.gov (United States)

    Matsumoto, Kazuhiko; Harinaga, Ukyo; Tanaka, Ryo; Koyama, Akira; Hagiwara, Rika; Tsunashima, Katsuhiko

    2014-11-21

    The structures of 16 symmetric tetraalkylammonium (Nn(+)) and tetraalkylphosphonium (Pn(+)) salts ([Nn][BF4], [Nn][PF6], [Pn][BF4], and [Pn][PF6], where n = 1 to 4, and denotes the number of carbon atoms in each alkyl chain) have been investigated by X-ray diffraction in order to elucidate the effect of ion size on the disordered structure of organic salts. All the salts exhibit one or more solid-solid phase transitions in differential scanning calorimetric curves. Powder X-ray diffraction revealed that the highest temperature solid phase of these salts belongs to a crystal system with a high cubic or hexagonal symmetry. The structures are classified into 5 different types: CsCl', NaCl, NaCl', inverse NiAs, and TBPPF6. The CsCl'-type whose octant corresponds to the original CsCl unit cell is observed for [N1][PF6] owing to the orientational difference for the cation or the anion. The NaCl-type structure is observed for the N2(+) and P2(+) salts while the NaCl'-type structure is observed for [N3][PF6], where the configuration of ions is based on the NaCl-type but the four equivalent positions in the original NaCl lattice split into two sets of equivalent positions (three and one). The inverse NiAs structure is observed for [P3][PF6]. Single-crystal X-ray diffraction reveals that the disordering of ions in [P4][PF6] becomes more significant with increasing temperature. The new structure of a cubic phase, the TBPPF6-type structure, is found for the salts with long alkyl chains. The structure is roughly determined at 333 K and the ions therein are highly disordered but not rotating. The validity of the radius ratio rule is confirmed through appropriate assessment of the ion size.

  3. Rate theory of solvent exchange and kinetics of Li+ - BF4-/PF6- ion pairs in acetonitrile

    Science.gov (United States)

    Dang, Liem X.; Chang, Tsun-Mei

    2016-09-01

    In this paper, we describe our efforts to apply rate theories in studies of solvent exchange around Li+ and the kinetics of ion pairings in lithium-ion batteries (LIBs). We report one of the first computer simulations of the exchange dynamics around solvated Li+ in acetonitrile (ACN), which is a common solvent used in LIBs. We also provide details of the ion-pairing kinetics of Li+-[BF4] and Li+-[PF6] in ACN. Using our polarizable force-field models and employing classical rate theories of chemical reactions, we examine the ACN exchange process between the first and second solvation shells around Li+. We calculate exchange rates using transition state theory and weighted them with the transmission coefficients determined by the reactive flux, Impey, Madden, and McDonald approaches, and Grote-Hynes theory. We found the relaxation times changed from 180 ps to 4600 ps and from 30 ps to 280 ps for Li+-[BF4] and Li+-[PF6] ion pairs, respectively. These results confirm that the solvent response to the kinetics of ion pairing is significant. Our results also show that, in addition to affecting the free energy of solvation into ACN, the anion type also should significantly influence the kinetics of ion pairing. These results will increase our understanding of the thermodynamic and kinetic properties of LIB systems.

  4. Organic metal (EDO-TTF2PF6 with multi-instability

    Directory of Open Access Journals (Sweden)

    Hideki Yamochi and Shin-ya Koshihara

    2009-01-01

    Full Text Available The multi-instability of the electronic structure of (EDO-TTF2PF6, where EDO-TTF means ethylene-dioxytetrathiafulvalene, is reviewed. This complex showed the metal–insulator transition at 280 K associated with distinct molecular deformations. The mechanism is interpreted as the cooperation of Peierls transition, charge ordering, and the order–disorder transition of the countercomponent. The charge ordering pattern in the low-temperature phase is of the novel [0, 0, 1, 1] type. The sensitivity of the electronic state to external perturbations is demonstrated applying not only static but also instantaneous stimuli. In the latter case, the photo-induced phase transition is ultrafast and highly efficient. One photon causes the transition of several hundreds of donor molecules in the low-temperature phase to relax into a highly conducting metastable state within about 1.5 ps. In the early stage of the transient state, the charge ordering of the [1, 0, 1, 0] type occurs. As for the chemical modifications of this material, the partial deuteration of this complex increases the metal–insulator transition temperature. The introduction of a methyl group greatly modulates the electronic structure of the complex, i.e. (methyl-EDO-TTF2X (X=BF4, ClO4 shows a two-dimensional electronic structure. The working hypotheses for developing the systems with multi-instability are described.

  5. Dehumidification performance of [EMIM]BF4

    International Nuclear Information System (INIS)

    Some ionic liquids have dehumidification capacity and are non-corrosive to metals. Based on the Finite Difference Method, the heat and moisture transfer model of the counter-flow dehumidifier was established. Using this model, the dehumidification capacity of one kind of ionic liquids 1-Ethyl-3-methylimidazolium Tetrafluoroborate ([EMIM]BF4) and traditional desiccant lithium bromide (LiBr) was compared in equivalent conditions. The results show that the dehumidification performances of the two solutions both improve with the increase of air flow rate, solution flow rate and air humidity. Even though the dehumidification rate of [EMIM]BF4 is a little lower than that of LiBr, such difference could be reduced by increasing the mass concentration of [EMIM]BF4. Meanwhile, compared with traditional desiccants, [EMIM]BF4 solution has significantly lower corrosion to metals and does not crystallize at high mass concentration, which render it a possible substitute of existed desiccants in liquid desiccant air conditioning systems. - Highlights: → The paper researched on using [EMIM]BF4 solution as desiccant in the liquid desiccant air conditioning system by simulation. → By comparing the dehumidification performance of [EMIM]BF4 solution with traditional desiccant LiBr solution, it confirms the feasibility of using [EMIM]BF4 as desiccant. → [EMIM]BF4 solution has significantly lower corrosion of metals and does not crystallize at high mass concentration, which make it a possible substitute of existed desiccants.

  6. Densities and viscosities for ionic liquids mixtures containing [eOHmim][BF4], [bmim][BF4] and [bpy][BF4

    International Nuclear Information System (INIS)

    Highlights: • Targets of this research are ILs mixtures. • Densities and viscosities were measured for three ILs mixtures. • Excess molar properties were deduced from the experiments. • Viscosities were discussed by the ideal Grunberg and Nissan mixing law. - Abstract: Densities and viscosities of binary ionic liquids mixtures, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([eOHmim][BF4]) + 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([eOHmim][BF4]) + N-butylpyridinium tetrafluoroborate ([bpy][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) + N-butylpyridinium tetrafluoroborate ([bpy][BF4]) were measured over the entire mole fraction from T = (298.15 to 343.15) K. The excess molar volumes were calculated and correlated by Redlich–Kiser polynomial expansions. The viscosities for pure ionic liquids were analyzed by means of the Vogel–Tammann–Fulcher equation and ideal mixing rules were applied for the ILs mixtures

  7. Role of PF6- in the radiolytical and electrochemical degradation of propylene carbonate solutions

    Science.gov (United States)

    Ortiz, Daniel; Jimenez Gordon, Isabel; Legand, Solène; Dauvois, Vincent; Baltaze, Jean-Pierre; Marignier, Jean-Louis; Martin, Jean-Frédéric; Belloni, Jacqueline; Mostafavi, Mehran; Le Caër, Sophie

    2016-09-01

    The behavior under irradiation of neat propylene carbonate (PC), a co-solvent usually used in Li-ion batteries (LIB), and also of Li salt solutions is investigated. The decomposition of neat PC is studied using radiolysis in the pulse and steady state regime and is assigned to the ultrafast formation, in the reducing channel, of the radical anion PCrad - by electron attachment, followed by the ring cleavage, leading to CO. In the oxidative channel, the PC(sbnd H)rad radical is formed, generating CO2. The CO2 and CO yields are both close to the ionization yield of PC. The CO2 and CO productions in LiClO4, LiBF4 and LiN(CF3)2(SO2)2 solutions are similar as in neat PC. In contrast, in LiPF6/PC a strong impact on PC degradation is measured with a doubling of the CO2 yield due to the high reactivity of the electron towards PF6- observed in the picosecond range. A small number of oxide phosphine molecules are detected among the various products of the irradiated solutions, suggesting that most of them, observed in carbonate mixtures used in LIBs, arise from linear rather than from cyclical molecules. The similarity between the degradation by radiolysis or electrolysis highlights the interest of radiolysis as an accelerated aging method.

  8. Thermal stability of LiPF 6 salt and Li-ion battery electrolytes containing LiPF 6

    Science.gov (United States)

    Yang, Hui; Zhuang, Guorong V.; Ross, Philip N.

    The thermal stability of the neat lithium hexafluorophosphate (LiPF 6) salt and of 1 molal (m) solutions of LiPF 6 in prototypical Li-ion battery solvents was studied with thermogravimetric analysis (TGA) and on-line Fourier transform infrared (FTIR). Pure LiPF 6 salt is thermally stable up to 107 °C in a dry inert atmosphere, and its decomposition path is a simple dissociation producing lithium fluoride (LiF) as solid and PF 5 as gaseous products. In the presence of water (300 ppm) in the carrier gas, its decomposition onset temperature is lowered as a result of direct thermal reaction between LiPF 6 and water vapor to form phosphorous oxyfluoride (POF 3) and hydrofluoric acid (HF). No new products were observed in 1 m solutions of LiPF 6 in ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) by on-line TGA-FTIR analysis. The storage of the same solutions in sealed containers at 85 °C for 300-420 h did not produce any significant quantity of new products as well. In particular, no alkylflurophosphates were found in the solutions after storage at elevated temperature. In the absence of either an impurity like alcohol or cathode active material that may (or may not) act as a catalyst, there is no evidence of thermally induced reaction between LiPF 6 and the prototypical Li-ion battery solvents EC, PC, DMC or EMC.

  9. Study of the Ion Channel Behavior of Didodecyldimethylammonium Bromide Formed Bilayer Lipid Membrane Stimulated by PF-6

    Institute of Scientific and Technical Information of China (English)

    TONG,Yue-Hong; HAN,Xiao-Jun; WANG,Er-Kang

    2003-01-01

    Bilayer lipid membranes ( BLM ) formed from didodecyldimethylammonium bromide were made on the freshly exposed surface ofa glassy carbon (GC) ani were demonstrated by the ac impedance spectroscopy. The ion channels of membrane properties induced by PF6- were studied by the cyclic voltammetric methods.Experimental results indicated that the ion channel of BLM was open in the presence of the PF6- due to the interaction of PF6- with the BLM, while it was switched offin the absence of PF6-. Because the ion channel behavior was affected by the concentration of PF6-,a sensor for PF6- can be developed.

  10. Structure, phase transitions, dielectric and spectroscopic studies of the 2-aminopyrimidinium salts: [(2-NH 2C 4N 2H 3) 2H][ClO 4] and [2-NH 2C 4N 2H 4][BF 4

    Science.gov (United States)

    Czupiński, O.; Wojtaś, M.; Ciunik, Z.; Jakubas, R.

    2006-01-01

    Crystal structure of the 2-aminopyrimidinium derivatives: [(2-NH 2C 4N 2H 3) 2H][ClO 4] (I) and [2-NH 2C 4N 2H 4][BF 4] (II) has been determined at 100 K (I) and 293 K (II) by means of single crystal X-ray diffraction as monoclinic space group, P2/c and P2/n, respectively. The asymmetric part of the unit cell of (I) contains two symmetry independent 2-aminopyrimidine forming one dimeric cation and one disordered perchlorate anion. The structure of (II) consists of 2-aminopyrimidinium cation, [2-NH 2C 4N 2H 4] +, protonated at a pyrimidine ring-N atom and [BF 4] - anion. Differential scanning calorimetry (DSC) on perchlorate derivative ( 1:1), [2-NH 2C 4N 2H 3][ClO 4] (III)—being isomorphic to tetrafluoroborate one (I) at room temperature, reveals two phase transitions of first order: at 250/275 K and 390/410 K (cooling-heating, respectively), whereas the analog (II) only one transition at high temperatures—343/385 K. The dielectric studies in the frequency range 75 kHz - 10 MHz disclose relaxation process at high temperatures in salt (I). Infrared spectra of polycrystalline [2-NH 2C 4N 2H 4][BF 4] have been studied in the temperature range 300-420 K. Substantial changes in the temperature evolution of frequencies of internal modes of the 2-aminopyrimidinium cations and [BF 4] - anions near 390 K are due to the variations in the motion of both moieties and hydrogen bond configuration. The experimental studies indicate that all phase transitions taking place in studied 2-aminopyrimidinium derivatives are classified as an order-disorder.

  11. Identification of radiolytic products of [C4mim][PF6] underγ-irradiation

    Institute of Scientific and Technical Information of China (English)

    敖银勇; 徐敏; 彭静; 李久强; 翟茂林; 吴国忠

    2015-01-01

    The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by 19F NMR (G(F−)=0.14 µmol/J, G(HOP(O)F2)=0.053 µmol/J). Com-pared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.

  12. Structure and properties of Li@C60-PF6 endofullerene complex

    Science.gov (United States)

    Srivastava, Ambrish Kumar; Kumar, Abhishek; Misra, Neeraj

    2016-10-01

    Li@C60 is a prototype endofullerene, which has been widely studied. Employing density functional theory we study the interaction of Li@C60 with PF6 superhalogen, which leads to the formation of Li@C60-PF6 endofullerene complex. The spectral properties such as infrared and UV-visible spectra have been calculated, which agree well with corresponding experimental data. The vibrational assignments and electronic transitions in the complex have been explored. We have noticed that this complex is stabilized by charge transfer from Li@C60 to PF6, which results in its large dipole moment (20 Debye), high mean polarizability (494 a.u.) and significant mean hyperpolarizability (1500 a.u.). We, therefore, believe that Li@C60-PF6 endofullerene complex might attract further attention for their possible electrooptical applications due to its enhanced nonlinear optical properties.

  13. Thermal stability of LiPF6/EC+DMC+EMC electrolyte for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    WANG Qingsong; SUN Jinhua; CHEN Chunhua

    2006-01-01

    The thermal stability of lithium-ion battery electrolyte could substantially affect the safety of lithium-ion battery. In order to disclose the thermal stability of 1.0 mol·L-1 LiPF6/ethylene carbonate (EC)+dimethyl carbonate (DMC)+ethylmethyl carbonate (EMC) electrolyte, a micro calorimeter C80 micro calorimeter was used in this paper. The electrolyte samples were heated in argon atmosphere, and the heat flow and pressure performances were detected. It is found that LiPF6 influences the thermal behavior remarkably, with more heat generation and lower onset temperature. LiPF6/EC shows an exothermic peak at 212 ℃ with a heat of reaction -355.4J·g-1.DMC based LiPF6 solution shows two endothermic peak temperatures at 68.5 and 187 ℃ in argon filled vessel at elevated temperature. EMC based LiPF 6 solution shows two endothermic peak temperatures at 191 and 258 ℃ in argon filled vessel.1.0mol·L-1LiPF6/EC+DMC+ EMC electrolyte shows an endothermic and exothermic process one after the other at elevated temperature. By comparing with the thermal behavior of single solvent based LiPF6 solution, it can be speculated that LiPF6 may react with EC, DMC and EMC separately in 1.0 mol·L-1LiPF6/EC+DMC+EMC electrolyte, but the exothermic peak is lower than that of 1.0 mol·L-1LiPF6/EC solution. Furthermore, The 1.0 mol·L-1 LiPF6 /EC+DMC+EMC electrolyte decomposition reaction order was calculated based on the pressure data, its value is n =1.83, and the pressure rate constants kp=6.49×10-2k Pa·-0.83·min-1 .

  14. Zero-Pressure Organic Superconductor: Di-(Tetramethyltetraselenafulvalenium)-Perchlorate [(TMTSF)2ClO4

    DEFF Research Database (Denmark)

    Bechgaard, Klaus; da Costa Carneiro, Kim; Olsen, Malte;

    1981-01-01

    Evidence for superconductivity in the organic conductor di-(tetramethyltetraselenafulvalenium)-perchlorate [(TMTSF)2ClO4] has been found by resistance measurements in the absence of applied pressure. For different crystals the transitions are approximately 0.3 K wide and are centered around tempe...... temperatures between 1.2 and 1.4 K. At 0.9 K, a perpendicular magnetic field of 25 mT nearly restores normal resistance. Below 0.1 K, this critical field exceeds 50 mT....

  15. Cooperative phenomena in (TMTSF)2ClO4 : an NMR evidence

    OpenAIRE

    Bourbonnais, C.; Creuzet, F.; Jérome, D.; Bechgaard, K.; Moradpour, A.

    1984-01-01

    We present 1H and 77Se NMR relaxation data on oriented (TMTSF)2ClO4 single crystals in the relaxed state. The data show the existence of three distinct regimes for the nuclear relaxation rate T-11. In the high temperature part (T > 25 K) the Korringa law seems to be well satisfied whereas in the lower temperature part we have strong deviations down to 8 K or so. At T ≲ 6 K, a different and enhanced Korringa regime appears to be restored. Preliminary results on (TMTSF)2FSO3 under pressure also...

  16. Characterization of plasticized PMMA–LiBF4 based solid polymer electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; T Uma

    2000-02-01

    Polymer electrolyte films prepared from poly(methyl methacrylate) and LiBF4 with different concentrations of plasticizer (DBP) are described. The formation of polymer–salt complex has been confirmed by FTIR spectral studies. The temperature dependence of conductivity of polymer films seems to obey the VTF relation. Values of conductivities of the polymer complexes are presented and discussed.

  17. Structural, spectroscopic and magnetic properties of [Cu(1-meim)4].2(PF6)

    Science.gov (United States)

    Yıldırım, Ilkay; Karabulut, Bünyamin

    2016-03-01

    [Cu(1-meim)4].2(PF6) (1-meim: 1-methylimidazole) complex has been synthesized and characterized by EPR, FT-IR, and XRD techniques. The Cu(II) complex crystallizes in the monoclinic system with the space group P21/c. EPR spectrum of [Cu(1-meim)4].2(PF6) powder has been studied at room temperature. The spin Hamiltonian parameters (g and hyperfine values) have been calculated. The results indicate the axial symmetry around the paramagnetic Cu2+ center. 2 2 The ground state wave function of Cu2+ ion has been constructed. The unpaired electron spends most of its time in dx2-y2 orbital.

  18. Positron 2D-ACAR study of the quasi-one-dimensional organic superconductor (TMTSF)2ClO4

    International Nuclear Information System (INIS)

    We have measured electron-positron momentum density in (TMTSF)2ClO4 by the positron two-dimensional angular correlation of annihilation radiation (2D-ACAR) technique. In order to interpret the experimental results, the electronic structure of (TMTSF)2ClO4 as well as the positron state therein has been investigated by ab initio theoretical calculations. 2D-ACAR spectra have been also calculated and compared with the experimental ones through their anisotropies and Lock-Crisp-West remapped spectra. The Fermi-surface-related structure is discussed. (orig.)

  19. Dimensionality Crossover in the Organic Superconductor Tetramethyltetraselenafulvalene Hexafluorophosphate [(TMTSF)2PF6

    DEFF Research Database (Denmark)

    Jacobsen, Claus Schelde; Tanner, D. B.; Bechgaard, K.

    1981-01-01

    Polarized reflectance measurements from the far infrared to the visible are reported for (TMTSF)2PF6. At low temperatures, both parallel and perpendicular polarizations show plasma edges in the infrared with metallic reflection below these edges, indicating two- or three-dimensional behavior. The...

  20. Fridel-Crafts acylation using bismuth triflate in [BMI][PF6

    DEFF Research Database (Denmark)

    Tran, Phuong Hoang; Duus, Fritz; Le, Thach Ngoc

    2012-01-01

    Bismuth trifluoromethanesulfonate was found to be a good catalyst for the Friedel–Craftsacylation. Bismuthtriflate immobilized in an ionic liquid was the most efficient catalytic system. Bismuthtriflate in [BMI][PF6] catalyzes this reaction under microwave irradiation allowing the rapid synthesis...

  1. Low temperature specific heat of the spin-density-wave compound (TMTSF)2PF6

    DEFF Research Database (Denmark)

    Odin, J.; Lasjaunias, J.C.; Biljakovic, K.;

    1994-01-01

    We report on specific heat measurements of the SDW compound (TMTSF)2PF6 between 2 and 25 K, performed by two different techniques. We discuss the two successive transitions which occur in this T-range : the SDW ordering transition at T = 12.1 K, and a glass transition around-3-3.5 K. The latter...

  2. Investigation of toxic effects of imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], on marine mussel Mytilus galloprovincialis with or without the presence of conventional solvents, such as acetone.

    Science.gov (United States)

    Tsarpali, Vasiliki; Belavgeni, Alexia; Dailianis, Stefanos

    2015-07-01

    This study investigated the cytotoxic, oxidative and genotoxic effects of two commonly used imidazolium ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium) and [omim][BF4] (1-methyl-3-octylimidazolium tetrafluoroborate), on the marine mussel Mytilus galloprovincialis, as well as whether acetone could mediate their toxic profile. In this context, mussels were firstly exposed to different concentrations of [bmim][BF4] or [omim][BF4], with or without the presence of acetone (at a final concentration of 0.06% v/v), for a period of 96h, in order to determine the concentration that causes 50% mussel mortality (LC50 values) in each case. Thereafter, mussels were exposed to sub- and non-lethal concentrations of ILs for investigating their ability to cause lysosomal membrane impairment (with the use of neutral red retention assay/NRRT), superoxide anion and lipid peroxidation byproduct (malondialdehyde/MDA) formation, as well as DNA damage and formation of nuclear abnormalities in hemocytes. The results showed that [omim][BF4] was more toxic than [bmim][BF4] in all cases, while the presence of acetone resulted in a slight attenuation of its toxicity. The different toxic behavior of ILs was further revealed by the significantly lower levels of NRRT values observed in [omim][BF4]-treated mussels, compared to those occurring in [bmim][BF4] in all cases. Similarly, [bmim][BF4]-mediated oxidative and genotoxic effects were observed only in the highest concentration tested (10mgL(-1)), while [omim][BF4]-mediated effects were enhanced at lower concentrations (0.01-0.05mgL(-1)). Overall, the present study showed that [bmim][BF4] and [omim][BF4] could induce not only lethal but also nonlethal effects on mussel M. galloprovincialis. The extent of [bmim][BF4] and/or [omim][BF4]-mediated effects could be ascribed to the length of each IL alkyl chain, as well as to their lipophilicity. Moreover, the role of acetone on the obtained toxic effects of the specific ILs was

  3. Electrodeposition of tin from EMI⋅BF4⋅Cl room temperature molten salts

    Directory of Open Access Journals (Sweden)

    Morimitsu M.

    2003-01-01

    Full Text Available The electrochemistry of Sn(II was investigated with cyclic voltammetry and chronoamperometry in the 1-ethyl-3-methylimidazolium tetrafluoroborate molten salt containing free chloride ions (EMI ⋅BF4 ⋅Cl originated from the mixture of EMIC and NaBF4 (60:40 mol%. The well defined redox waves for the electro deposition and dissolution of tin were observed on a platinum electrode at 303 K. The deposition of tin proceeded through a quasi-reversible step with two electron transfer, and the deposited tin was sufficiently recovered during oxidation. The experimental current-time transient coincided with the theory based on one-dimensional diffusion control.

  4. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    International Nuclear Information System (INIS)

    Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li+ ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10−2 S cm−1 for chitosan to 1.30 × 10−2 S cm−1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM)

  5. Synthesis and characterization of ionic liquid (EMImBF4)/Li+ - chitosan membranes for ion battery

    Science.gov (United States)

    Pasaribu, Marvin H.; Arcana, I. Made; Wahyuningrum, Deana

    2015-09-01

    Lithium ion battery has been currently developed and produced because it has a longer life time, high energycapacity, and the efficient use of lithium ion battery that is suitable for storing electrical energy. However, this battery has some drawbacks such as use liquid electrolytes that are prone to leakage and flammability during the battery charging process in high temperature. In this study, an ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) containing Li+ ions was synthesized and combined with chitosan polymer host as a polymer electrolyte membrane for lithium-ion batteries to solve this problems. This ionic liquid was obtained from the anion metathesis reaction between EMImBr and LiBF4 salt, while EMImBr was synthesized from the reaction between 1-methylimidazole and ethyl bromide utilizing Microwave Assisted Organic Synthesis (MAOS) method. The ionic liquid obtained was characterized by microstructure analysis with using NMR and FTIR spectroscopy. The polymer electrolyte membrane was characterized by analysis functional groups (FTIR), ionic conductivity (EIS), and surface morphology (SEM). The analysis results of ion conductivity by the EIS method showed the increase the ionic conductivity value of membranes from 1.30 × 10-2 S cm- 1 for chitosan to 1.30 × 10-2 S cm-1 for chitosan with EMImBF4/Li+, and this result was supported by analysis the surface morphology (SEM).

  6. Anisotropy of the upper critical field in ultrahigh-pressure-induced superconductor (TMTTF)2PF6

    International Nuclear Information System (INIS)

    We have measured the temperature dependence of resistivity of (TMTTF)2PF6 under high pressures up to 7 GPa by using a turnbuckle DAC (diamond anvil cell) for pressurization, also in magnetic field up to 5 T. In superconducting transition, zero-resistivity was successfully observed even there are not many cases that zero-resistivity has been observed from measurements of organics under high pressures. Superconductivity was observed at P=4.18-6.03 GPa and showed the highest TC of 2.25 K at 4.58 GPa. The temperature dependence of the upper critical magnetic field HC2(T) was determined via resistivity at P=4.58 GPa, for the intrachain (a), interchain (b'), and interlayer (c*). Also, the values of GL coherence lengths for three different axis which obtained from this work show that (TMTTF)2PF6 is anisotropic three-dimensional superconductor.

  7. Thermodynamics of Imidazolium-Based Ionic Liquids Containing PF6 Anions.

    Science.gov (United States)

    Zaitsau, Dzmitry H; Yermalayeu, Andrei V; Emel'yanenko, Vladimir N; Butler, Simon; Schubert, Thomas; Verevkin, Sergey P

    2016-08-18

    Imidazolium-based ionic liquids (ILs) with PF6(-) anions are considered as low-cost solvents for separation processes, but they exhibit restricted thermal stabilities. Reliable measurements of vaporization thermodynamics by conventional methods have failed. In this work, we applied a quartz-crystal microbalance method to determine for the first time the absolute vapor pressures for the [Cnmim][PF6] family, with n = 2, 4, 6, 8, and 10, in the temperature range 403-461 K. An absence of decomposition of ILs in experimental conditions was determined by the attenuated total reflection-infrared spectroscopy. The consistency of the experimental results within the homologous series was established through enthalpy and entropy analyses of the liquid and gas phases as well as by molecular dynamics simulations. PMID:27462931

  8. Polymorphism in the spin-crossover ferric complexes [(TPA)Fe(III)(TCC)]PF6.

    Science.gov (United States)

    Collet, Eric; Boillot, Marie Laure; Hebert, Johan; Moisan, Nicolas; Servol, Marina; Lorenc, Maciej; Toupet, Loïc; Buron-Le Cointe, Marylise; Tissot, Antoine; Sainton, Joelle

    2009-08-01

    We have identified two polymorphs of the molecular complex [(TPA)Fe((III))(TCC)]PF(6) [TPA = tris(2-pyridylmethyl)amine and TCC = 3,4,5,6-tetrachlorocatecholate dianion]: one is monoclinic and the other is orthorhombic. By lowering the temperature both undergo a thermal spin-crossover between a high-spin (S = 5/2) and a low-spin (S = 1/2) state, which we detected by magnetic, optical and X-ray diffraction measurements. The thermal crossover is only slightly shifted between the polymorphs. Their crystalline structures consist of similar cation layers alternating with PF(6) anion layers, packed differently in the two polymorphs. The magnetic and optical properties of the polymorphs are presented.

  9. In situ crystallization of ionic liquid [Emim][PF6] from methanol solution under high pressure.

    Science.gov (United States)

    Li, Haining; Su, Lei; Zhu, Xiang; Cheng, Xuerui; Yang, Kun; Yang, Guoqiang

    2014-07-24

    The solubility of 1-ethyl-3-methylimidazolium hexafluorophosphate ([Emim][PF6]) in methanol under high pressure is newly measured quantitatively according to the correlation between the ratios of Raman intensity and the concentrations. In situ crystallization and cation conformation of [Emim][PF6] from methanol solution under high pressure have been investigated by using Raman spectroscopy in detail. Remarkably, crystal polymorphism was observed and two crystalline phases (phases I and II) coexisted under high pressure up to ∼ 1.4 GPa. However, only phase II was obtained by recrystallization at ∼ 2 GPa. Our findings may facilitate the development of an effective way for crystallization and purification of ionic liquids under high pressure.

  10. Solvent relaxation of a room-temperature ionic liquid [bmim][PF6] confined in a ternary microemulsion

    Indian Academy of Sciences (India)

    Debabrata Seth; Palash Setua; Anjan Chakraborty; Nilmoni Sarkar

    2007-03-01

    In this paper we have reported the solvent and rotational relaxation of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) confined in tween 20/([bmim][PF6]/water microemulsion using coumarin 153 (C-153) as probe. The most interesting feature of our experiment was that we observed an increase in solvent relaxation time with increase in ( = tween 20-to-[bmim][PF6] molar ratio). This is due to the fact that with increase in [bmim][PF6] content of the microemulsions, the microviscosity of the pool of the microemulsions increases, and motion of ions of [bmim][PF6] is hindered in the pool of microemulsions. Since motion of ions is responsible for solvation in room-temperature ionic liquids (RTILs), solvent-relaxation time increases with increase in .

  11. Extraction of Yttrium (Ⅲ) into [C8mim][PF6] Containing Cyanex 923

    Institute of Scientific and Technical Information of China (English)

    Peng Bo; Sun Xiaoqi; Chen Ji; Ma Jiutong

    2007-01-01

    The extraction of Yttrium (Ⅲ) into [Cnmim] [PF6] (n=4,6,8) containing Cyanex 923 was studied in this paper. The mechanism of this extraction was indicated to be cation exchange. In addition, the extraction process is an endothermic reaction. The RTILs with shorter alkyl chain behave higher extraction efficiency during the extraction, however, which has also more loss to aqueous phase since the cation exchange mechanism.

  12. Magnetic-field-induced modifications of the electronic structure of Ni(en)2NO2BF4 : A signature of the Haldane gap in the electronic-excitation intensities

    Science.gov (United States)

    Long, V. C.; Chou, Y.-H.; Cross, I. A.; Kozen, A. C.; Montague, J. R.; Schundler, E. C.; Wei, X.; McGill, S. A.; Landry, B. R.; Maxcy-Pearson, K. R.; Turnbull, M. M.; Landee, C. P.

    2007-07-01

    Ni(en)2NO2BF4 (NENB) is isostructural to Ni(en)2NO2ClO4 , the well-known Haldane compound. We have measured the near infrared and visible frequency polarized transmittances of NENB as a function of temperature from 6to300K and in magnetic fields (H) up to 30T . We identify near infrared spin-allowed and spin-forbidden (SF) d-d excitations of the Ni2+ ion as well as a Ni2+ -to- NO2- charge-transfer (CT) transition at 2.5eV , confirmed by vibrational fine structure on the CT band due to the nitrite ion. The spin-allowed d-d bands exhibit temperature dependence consistent with vibronic transitions. The spin-forbidden and electron transfer transitions are noticeably sensitive to magnetic field. Above H≈10T , the NENB SF excitation is linearly suppressed by field, whereas the CT transition intensity increases; the onset field agrees with that observed in the high-field magnetization. For comparison, we made the same measurements on a compound having similar near infrared electronic transitions but a different magnetic ground state: the paramagnetic material Ni(en)3(ClO4)2•H2O (NEN3P). The SF bands of NENB are relatively more intense than those of NEN3P, suggesting that a spin exchange mechanism enhances their intensity in NENB, in contrast to activation solely by spin-orbit coupling in NEN3P. The H dependence of the SF band also differs in the two materials; in NEN3P, suppression of the SF intensity commences at H≈0T . In general, the contrasting behaviors of field-sensitive excitations in the Haldane and paramagnetic analog compounds reveal a correlation between the electronic structure and magnetic properties.

  13. The photochemistry of [Fe(III)N3(cyclam-ac)]PF6 at 266 nm.

    Science.gov (United States)

    Torres-Alacan, Joel; Krahe, Oliver; Filippou, Alexander C; Neese, Frank; Schwarzer, Dirk; Vöhringer, Peter

    2012-03-01

    The photochemistry of iron azido complexes is quite challenging and poorly understood. For example, the photochemical decomposition of [Fe(III)N(3)(cyclam-ac)]PF(6) ([1]PF(6)), where cyclam-ac represents the 1,4,8,11-tetraazacyclotetradecane-1-acetate ligand, has been shown to be wavelength-dependent, leading either to the rare high-valent iron(V) nitrido complex [Fe(V)N(cyclam-ac)]PF(6) ([3]PF(6)) after cleavage of the azide N(α)-N(β) bond, or to a photoreduced Fe(II) species after Fe-N(azide) bond homolysis. The mechanistic details of this intriguing reactivity have never been studied in detail. Here, the photochemistry of 1 in acetonitrile solution at room temperature has been investigated using step-scan and rapid-scan time-resolved Fourier transform infrared (FTIR) spectroscopy following a 266 nm, 10 ns pulsed laser excitation. Using carbon monoxide as a quencher for the primary iron-containing photochemical product, it is shown that 266 nm excitation of 1 results exclusively in the cleavage of the Fe-N(azide) bond, as was suspected from earlier steady-state irradiation studies. In argon-purged solutions of [1]PF(6), the solvent-stabilized complex cation [Fe(II)(CH(3)CN)(cyclam-ac)](+) (2red) together with the azide radical (N(3)(.)) is formed with a relative yield of 80%, as evidenced by the appearance of their characteristic vibrational resonances. Strikingly, step-scan experiments with a higher time resolution reveal the formation of azide anions (N(3)(-)) during the first 500 ns after photolysis, with a yield of 20%. These azide ions can subsequently react thermally with 2red to form [Fe(II)N(3)(cyclam-ac)] (1red) as a secondary product of the photochemical decomposition of 1. Molecular oxygen was further used to quench 1red and 2red to form what seems to be the elusive complex [Fe(O(2))(cyclam-ac)](+) (6).

  14. Studies on the thermal decomposition kinetics of LiPF6 and LiBC4O8

    Indian Academy of Sciences (India)

    Li Shi-You; Ma Pei-Hua; Cui Xiao-Ling; Ren Qi-Du; Li Fa-Qiang

    2008-03-01

    Thermal decomposition of LiPF6 and LiBC4O8 (lithium bis(oxalate)borate, abbreviated as LiBOB) were studied using TG (thermogravimetry)-DTG (derivative thermogravimetry) method with different heating rate of 5, 10, 20 and 40°C min-1 or at different constant temperature C (109.80, 118.79, 148.41, 176.86 °C for LiPF6 and 278.51, 298.13, 317.65, 336.13 for LiBOB). From the nonisothermal kinetics we calculate that LiPF6 is 1.01, LiBOB is 1.04, LiPF6 is 91907.61 J/mol, and LiBOB is 205179.88 J/mol; from the isothermal kinetics we calculate that n for both LiPF6 and LiBOB are 1, LiPF6 is 91907.61 J/mol, LiBOB is 205179.88 J/mol, lnALiPF6 is 16.89 s-1, and lnALiBOB is 31.96 s-1. The results obtained from the two ways have minor differences and can validate each other.

  15. Effect of C8mimPF6 on miniemulsion polymerization for application in new latex coating products.

    Science.gov (United States)

    Hu, Binjie; Kong, Yiyang; Zheng, Rongmeihui; Dong, Jie; Choy, Kwang-Leong; Zhao, Huanhuan

    2016-08-15

    C8mimPF6, as a type of room temperature ionic liquid (RTIL) with non-volatility and a low melting point, may replace conventional coalescing agents in latex coatings, thus preventing volatile organic compound (VOC) emissions caused by coalescing agents. In this study, systematic investigations on the effect of various factors including initiator type, initiator concentration, temperature and C8mimPF6 concentration on the conversion of latex and droplet/particle size of a miniemulsion during polymerization have been conducted. The presence of C8mimPF6 has shown to have a marked effect on the reaction rate. Such an effect strongly depends on the type of initiator being used. For polymerization initiated by 2,2-azobis (isobutyronitrile) (AIBN), C8mimPF6 had a promoting effect on the reaction rate at low concentrations, but this effect might be reversed upon certain C8mimPF6 concentrations, e.g. 10 wt%. While initiated by H2O2/Vc, this promoting effect faded even at low C8mimPF6 concentrations. The different limiting factors, which determine the reaction rate with different types of initiator, may contribute to the results. For reactions initiated by hydrophobic AIBN, the reaction was dominated by kinetics. The presence of C8mimPF6 may cause an enhanced chain propagation rate and reduced chain termination rate, which may further contribute to the increase in reaction rate at lower concentrations of C8mimPF6. With hydrophilic H2O2/Vc, the resistance for the transfer of radicals into a droplet/particle might be increased significantly with increasing C8mimPF6 concentration due to a tighter interfacial structure at lower concentrations of C8mimPF6. Thus, such transfer of radicals may become a limiting step whilst the presence of C8mimPF6 increases the transfer resistance on radicals resulting in a decrease in reaction rate. The reaction temperature, which is related to the decomposition temperature of the initiator being used, was another factor affecting the conversion

  16. Optimization of performances of gelatin/LiBF4-based polymer electrolytes by plasticizing effects

    International Nuclear Information System (INIS)

    Gelatin is a cheap and abundant natural product with very good biodegradation properties and can be used to obtain acetic acid or LiClO4-based gel polymer electrolytes (GPEs) with high ionic conductivity and good stability. This article presents results of GPEs obtained by the plasticization of gelatin and addition of LiBF4, where the optimization of the system was achieved by using a factorial design type 22 with two variables: glycerol and LiBF4. From this analysis it was stated that the effect of glycerol as a plasticizer on the ionic conductivity results is much more important than the effect obtained by varying the lithium salt content or the effect of the interaction of both variables. Also all the samples were characterized by X-ray diffraction measurements, UV-vis-NIR spectroscopy and scanning electron microscopy (SEM) and impedance spectroscopy. The ionic conductivity results of all analyzed samples as a function of temperature obey predominantly an Arrhenius relationship and the samples are stable up to 160 deg. C. Good conductivity results combined with transparency and good adhesion to the electrodes have shown that gelatin-based GPEs are very promising materials to be used as solid electrolytes in electrochromic devices.

  17. Glass transition in the spin-density wave phase of (TMTSF)2PF6

    DEFF Research Database (Denmark)

    Lasjaunias, J.C.; Biljakovic, K.; Nad, F.;

    1994-01-01

    We present the results of low frequency dielectric measurements and a detailed kinetic investigation of the specific heat anomaly in the spin-density wave phase of (TMTSF)(2)PF6 in the temperature range between 2 and 4 K. The dielectric relaxation shows a critical slowing down towards a ''static'......'' glass transition around 2 K. The jump in the specific heat in different controlled kinetic conditions shows all the characteristics of freezing in supercooled liquids. Both effects give direct evidence of a glass transition in the spin-density wave ground state....

  18. Synthesis of Aryl Allyl Ether in the Recyclable Ionic Liquid [bmim]PF6

    Institute of Scientific and Technical Information of China (English)

    Zhou Mei-Yun; Li Yi-Qun; Xu Xin-Ming

    2004-01-01

    Ionic liquids, especially imidazonium salts, have recently gained recognition as possible environmentally benign alternative chemical process solvents. This is mainly due to their nonvolatile nature, insolubility in some solvents as well as their ability to dissolve a wide range of organic and inorganic materials, allowing the ionic liquids easy recovery and recycling. Examples of their application in organic reactions have been summarized in a number of recent review articles.1Aryl allyl ether is very useful intermediate in organic synthesis. The Williamson reaction is a well knows method for the preparation ethers. However, the reaction of alkylating agents with the phenoxide ions was conventionally carried out in the organic solvents. The usual solvents for this type of reaction are DCM, 2 DMSO, 3 DMF, 4 CH3CN5 etc. With the current desire to avoid the use of organic molecular solvents in organic synthesis, we decide to investigate the use of the ionic liquid for the alternative solvent for the Williamson reaction to prepare the aryl allyl ethers. The ionic liquid employed here was the moisture stable 1-butyl-3-methylimidazolium hexafluorophosphate [bmim]PF6.6 The ionic liquid is non-volatile, thermally stable, and depending on the anion, can present low immiscible with water,alkanes and dialky ethers. We have now found that aryl allyl ethers can have been obtained from various phenols and allyl bromide in the presence of potassium hydroxide in [bmim]PF6 as a replacement for classical organic solvents in the ambient temperature. The results are shown in Scheme 1.The reaction were carried out by simple mixing the phenolwith the ally bromide and potassium hydroxide in [bmim]PF6 and stirred at room temperature for 4h. The results are summarized in Table 1.In conclusion, Williamson reaction can be successfully conducted in ionic liquid [bmim]PF6 with a number of advantages: the procedure is simple, the reaction condition is mild and the yields are excellent

  19. Trans --> cis isomerization of trans-[(dppm)2Ru(H)(L)][BF4] (L = P(OR)3) complexes: preparation of cis-[(dppm)2Ru(eta2-H2)(L)][BF4]2.

    Science.gov (United States)

    Mathew, Nisha; Jagirdar, Balaji R; Ranganathan, Anupama

    2003-01-13

    A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)(2)Ru(eta(2)-H(2))(L)][BF(4)](2) (dppm = Ph(2)PCH(2)PPh(2); L = P(OMe)(3), P(OEt)(3), PF(O(i)Pr)(2)) have been prepared by protonating the precursor hydride complexes cis-[(dppm)(2)Ru(H)(L)][BF(4)] (L = P(OMe)(3), P(OEt)(3), P(O(i)Pr)(3)) using HBF(4).Et(2)O. The cis-[(dppm)(2)Ru(H)(L)][BF(4)] complexes were obtained from the trans hydrides via an isomerization reaction that is acid-accelerated. This isomerization reaction gives mixtures of cis and trans hydride complexes, the ratios of which depend on the cone angles of the phosphite ligands: the greater the cone angle, the greater is the amount of the cis isomer. The eta(2)-H(2) ligand in the dihydrogen complexes is labile, and the loss of H(2) was found to be reversible. The protonation reactions of the starting hydrides with trans PMe(3) or PMe(2)Ph yield mixtures of the cis and the trans hydride complexes; further addition of the acid, however, give trans-[(dppm)(2)Ru(BF(4))Cl]. The roles of the bite angles of the dppm ligand as well as the steric and the electronic properties of the monodentate phosphorus ligands in this series of complexes are discussed. X-ray crystal structures of trans-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], cis-[(dppm)(2)Ru(H)(P(OMe)(3))][BF(4)], and cis-[(dppm)(2)Ru(H)(P(O(i)Pr)(3))][BF(4)] complexes have been determined. PMID:12513094

  20. Electropolymerization of 3-Methylthiophene in [BMIM]PF6 Ionic Liquid, Characterization and Application

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ai-Jian; QI Xi-Min; DU Yan-Fang; LUO Yi-Wen; FANG Hui-Jue; LU Jia-Xing

    2006-01-01

    Poly-3-methylthiophene (P3MT) was synthesized in the room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) by constant potential and constant current respectively. The structure and morphology of P3MT films were characterized by FTIR spectrum and SEM. The undoped (reduction) and doped (oxidation) forms of P3MT film prepared in ionic liquid were reversible and stable. The P3MT film has strong characteristics of electrocatalytic oxidation of ascorbic acid and can separate the oxidation peaks of ascorbic acid and dopamine. Two methods of potential steps were used to observe the response time of the film and the film was found to have perfect electrochromic response.

  1. Thermal reactions of mesocarbon microbead (MCMB) particles in LiPF 6-based electrolyte

    Science.gov (United States)

    Xiao, Ang; Li, Wentao; Lucht, Brett L.

    The thermal reaction of ternary electrolyte (1.0 M LiPF 6 in 1:1:1 ethylene carbonate/dimethyl carbonate/diethyl carbonate) with mesocarbon microbeads (MCMB) particles was investigated by the combined use of NMR, GC-MS, FTIR-ATR, TGA, XPS and SEM/EDS-element map. The thermal decomposition of ternary electrolyte is not inhibited by the presence of MCMB particles. The chemical composition and morphology of the surface of MCMB particles changes significantly upon storage in the presence of ternary electrolyte. Electrolyte decomposition products including oligocarbonates, oligoethylene oxides, polyethylene oxide (PEO), lithium fluorophosphates (Li xPO yF z), and lithium fluoride are deposited on the surface of MCMB particles. The concentration of decomposition products on the surface of MCMB increases with increased storage time and temperature. The addition of dimethyl acetamide (DMAc) impedes the thermal decomposition of the electrolyte and deposition of electrolyte decomposition products on the surface of MCMB.

  2. Ordering layers of [bmim][PF6] ionic liquid on graphite surfaces: molecular dynamics simulation.

    Science.gov (United States)

    Maolin, Sha; Fuchun, Zhang; Guozhong, Wu; Haiping, Fang; Chunlei, Wang; Shimou, Chen; Yi, Zhang; Jun, Hu

    2008-04-01

    Microscopic structures of room temperature ionic liquid (IL) [bmim][PF6] on hydrophobic graphite surfaces have been studied in detail by molecular dynamics simulation. It is clearly shown that both the mass and electron densities of the surface adsorbed ionic liquid are oscillatory, and the first peak adjacent to the graphite surface is considerably higher than others, corresponding to a solidlike IL bottom layer of 6 angstroms thick. Three IL layers are indicated between the graphite surface and the inner bulk IL liquid. The individually simulated properties of single-, double-, and triple-IL layers on the graphite surface are very similar to those of the layers between the graphite surface and the bulk liquid, indicating an insignificant effect of vapor-IL interface on the ordered IL layers. The simulation also indicates that the imidazolium ring and butyl tail of the cation (bmim+) of the IL bottom layer lie flat on the graphite surface.

  3. Enhanced Performance of Li|LiFePO4 Cells Using CsPF6 as an Electrolyte Additive

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Jiguang; Xu, Wu

    2015-10-20

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structure during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode was further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  4. Enhanced performance of Li|LiFePO4 cells using CsPF6 as an electrolyte additive

    Science.gov (United States)

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Ji-Guang; Xu, Wu

    2015-10-01

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structures during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode is further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  5. Biosorption of BF-4B Reactive Red Dye by using Leaves of Macrophytes Eichhornia crassipes

    Directory of Open Access Journals (Sweden)

    Aparecido Nivaldo Módenes

    2013-04-01

    Full Text Available The removal potential on BF-4B reactive red dye by Eichhornia crassipes dried leaves has been investigated. Furthermore, the influence of process parameters such as solution pH, agitation, and particle size on the dye adsorption efficiency was assessed. Both kinetic and equilibrium experiments were performed in batch operation of the system. Kinetic results demonstrated that the equilibrium state was achieved after 45 min process time. The kinetic experimental data were best described by applying a pseudo-second order model that evaluated the value of rate constant 0.22 g/mg/min and an equilibrium dye concentration 8.20 mg/g. A set of isotherm models, taken from knowledge database, was tested in order to represent the equilibrium adsorption data. The Langmuir model performed the best when fitting experimental data where the maximum adsorption capacity of 20.38 mg/g was achieved. The results demonstrated that the E. crassipes has good potential to be used as a biosorbent in industrial treatment systems to remove reactive dyes from textile effluents.

  6. Explanation of the site-specific spin crossover in Fe(mtz)(6)(BF4)(2)

    NARCIS (Netherlands)

    Rudavskyi, Andrii; Havenith, Remco W. A.; Broer, Ria; de Graaf, Coen; Sousa, Carmen

    2013-01-01

    The spin crossover behavior of the two [Fe(mtz)(6)](2+) complexes occupying different lattice sites in Fe(mtz)(6)(BF4)(2) is addressed by combining quantum chemical calculations with a careful analysis of the crystal structure. It is first established from the calculations that the energy difference

  7. Asymmetric Bilayer Muscles: Cooperative Actuation, Dynamic Hysteresis, and Creeping in NaPF6 Aqueous Solutions.

    Science.gov (United States)

    Fuchiwaki, Masaki; Martinez, Jose G; Fernandez Otero, Toribio

    2016-08-01

    Three bilayer muscles [polypyrrole-paraphenolsulfonic acid/polypyrrole-dodecylbenzensulfonic acid (PPy-HpPS/PPy-DBS) asymmetric bilayer, PPy-HpPS/tape, and PPy-DBS/tape] were characterized during potential cycling in NaPF6 aqueous solutions. In parallel, the angular displacement of the muscle was video-recorded. The dynamo-voltammetric (angle-potential) and coulo-dynamic (charge-potential) results give the reaction-driven ionic exchanges in each PPy film. Electrochemical reactions drive the exchange of anions from the PPy-HpPS layer and cations from the PPy-DBS layer. This means that both layers from the asymmetric bilayer follow complementary volume changes (swelling/shrinking or shrinking/swelling), owing to complementary ionic exchanges (entrance/expulsion) driven by the bilayer oxidation or reduction. The result is a cooperative actuation; the bending amplitude described by the asymmetric bilayer muscle is one order of magnitude larger than those attained from each of the conducting polymer/tape muscles. The cooperative actuation almost eliminates creeping effects. A large dynamical hysteresis persists, which can be attributed to an irreversible reaction of the organic acid components at high overpotentials.

  8. Graphene-Polypyrrole Nanocomposite as a Highly Efficient and Low Cost Electrically Switched Ion Exchanger for Removing ClO4- from Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sheng; Shao, Yuyan; Liu, Jun; Aksay, Iihan A.; Lin, Yuehe

    2011-10-10

    Perchlorate (ClO4-) contamination is now recognized as a widespread concern affecting many water utilities. In this report, graphene is employed as the scaffold to synthesize novel graphene-polypyrrole nanocomposite, which is demonstrated as excellent electrically switched ion exchanger for perchlorate removal. Scanning electron microscopy (SEM) and electrochemical measurements showed that the 3D nanostructured graphene/Ppy nanocomposite exhibited the significantly improved uptake capacity for ClO4- compared with Ppy film. X-ray photoelectron spectroscopy (XPS) confirmed the uptake and release process of ClO4- in graphene/Ppy nanocomposite. In addition, the presence of graphene substrate resulted in high stability of graphene/Ppy nanocomposite during potential cycling. The present work provides a promising method for large scale water treatment.

  9. Density Functional Theoretical Study of Polynitrogen Compounds N+5Y- (Y=B(CF3)4, BF4, PFe and B(N3)4)

    Institute of Scientific and Technical Information of China (English)

    廉鹏; 来蔚鹏; 常海波; 李亚南; 李辉; 杨威; 王友兵; 王伯周; 薛永强

    2012-01-01

    The structures and the stabilities of polynitrogen compounds N+5Y^- [Y=B(CF3)4, BF4, PF6, and B(N3)4], as the potential high energy density compounds, have been investigated at the B3LYP/6-31G(d,p) and B3LYP/6-311 +G(d,p) levels. On the basis of our geometry optimization calculations, the structural properties of the N+5Y^- compounds are discussed, and it is found that the combination of the N+ cation and the Y- anions leads to dis- tortion of the structures of the Y anions. Based on the TS calculations for the N2-10ss dissociations of the N+Y- compounds, the stabilities of these compounds are discussed, and the following conclusion can be drawn that among the four compounds, N+B(CF3)4 is the most stable one and N+B(N3)7 is the most unstable, and the relative stability of these compounds is always consistent using different basis sets. From these discussions, it is re- vealed that there are close correlations between the stuctrual distortions of the Y-anions and the stabilities of the N+Y- compounds, and between the nitrogen content in the compounds and the stabilities of the N+5Y^- compounds.

  10. Direct measurement of the chemical reactivity of silicon electrodes with LiPF6-based battery electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Veith, Gabriel M [ORNL; Baggetto, Loic [ORNL; Sacci, Robert L [ORNL; Unocic, Raymond R [ORNL; Tenhaeff, Wyatt E [ORNL; Browning, Jim [ORNL

    2014-01-01

    We report the first direct measurement of the chemistry and extent of reactivity between a lithium ion battery electrode surface (Si) and a liquid electrolyte (1.2M LiPF6-3:7 wt% ethylene carbonate:dimethyl carbonate). This layer is estimated to be 3.6 nm thick and partially originates from the consumption of the silicon surface.

  11. [Bmim]BF4-H2O体系超额摩尔体积测定及关联%Measurement and Correlation of Excess Molar Volume for the [Bmim]BF4-H2O System

    Institute of Scientific and Technical Information of China (English)

    方伟慧; 林金清; 王国平; 金春英

    2010-01-01

    合成并表征离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4),测定[Bmim]BF4-H2O二元混合物在不同温度下的密度值和超额摩尔体积.结果表明,在所有组成范围内,体系的超额摩尔体积都为正值,且不同温度下的等温线都存在一极大值点;同时,所有等温线的极值点所对应的H2O的摩尔分数基本上在50%左右.不同温度下超额摩尔集体的变化趋势相似,而在组成相同的情况下,随着温度的增加,超额摩尔体积变大.采用Redlich-Kister方程对[Bmim]BF4-H2O的超额摩尔体积进行关联,最大标准偏差为1.32%.

  12. Computational Studies of [Bmim][PF6]/n-Alcohol Interfaces with Many-Body Potentials

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Tsun-Mei; Dang, Liem X.

    2014-09-04

    In this paper, we present the results from molecular-dynamics simulations of the equilibrium properties of liquid/liquid interfaces of room temperature ionic liquid [bmim][PF6] and simple alcohols (i.e., methanol, 1-butanol, and 1-hexanol) at room temperature. Polarizable potential models are employed to describe the interactions among species. Results from our simulations show stable interfaces between the ionic liquid and n-alcohols, and we found that the interfacial widths decrease from methanol to 1-butanol systems, and then increase for 1-hexanol interfaces. Angular distribution analysis reveals that the interface induces a strong orientational order of [bmim] and n-alcohol molecules near the interface, with [bmim] extending its butyl group into the alcohol phase while the alcohol has the OH group pointing into the ion liquid region, which is consistent with the recent sum-frequency-generation experiments. We found the interface to have a significant influence on the dynamics of ionic liquids and n-alcohols. The orientational autocorrelation functions illustrate that [bmim] rotate more freely near the interface than in the bulk, while the rotation of n-alcohol is hindered at the interface. Additionally, the time scale associated with the diffusion along the interfacial direction is found to be faster for [bmim] but slowed down for n-alcohols approaching the interface. We also calculate the dipole moment of n-alcohols as a function of the distance normal to the interface. We found that, even though methanol and 1-butanol have different dipole moments in bulk phase, they reach a similar value at the interface. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the Department of Energy by Battelle. The calculations were carried out using computer resources provided by the

  13. 锂离子电池电解质盐LiPF6中微量水的测定%MEASUREMENT OF TRACE WATER IN LiPF6 ELECTROLYTE SALT OF LITHIUM ION BATTERY

    Institute of Scientific and Technical Information of China (English)

    王成俊; 郭爱红; 王凤花; 韩晓丽; 张宝贵

    2003-01-01

    采用把库仑法和卡尔-菲休法有效结合的库仑滴定法测定锂电池电解质中微量水份,对电解质盐六氟磷酸锂(LiPF6)样品的测定表明,该方法灵敏度为1μg,精密度高,结果比较理想.

  14. Research of [SOeBim][PF6] ionic liqnid as stationary phase for gas chromatography%[SOeBim][PF6]离子液体作为气相色谱固定相的研究

    Institute of Scientific and Technical Information of China (English)

    郑建华; 申书昌

    2015-01-01

    A kind of Silicone modified ionic liquid 1-ethyl-3-( 3-chloropropyl ) three hydroxy silane six benzimidazole fluorophosphate([SOeBim][PF6])was synthesized using 1-ethyl benzimidazole(3-chloropropyl) trimethoxysilane and six fluorine potassium phosphate as raw meterials,the structure and the stability of it were analyzed.[SOeBim][PF6] stationary liquid with silica hydroxyl on the surface of quartz reacted by chemical bonding method , the opening capillary column was prepared by this method . The separating characteristic of the chromatography column was investigated by benzene mixtures and alcohol mixtures respectively.%以1-乙基苯并咪唑、(γ-氯丙基)三甲氧基硅烷和六氟磷酸钾为原料,合成了一种硅氧烷改性的离子液体1-乙基-3-(γ-氯丙基)三羟基硅烷苯并咪唑六氟磷酸盐([SOeBim][PF6]),并对其结构及稳定性进行了分析。将[SOeBim][PF6]固定液用化学键合的方法与石英表面的硅羟基反应,制成开口毛细管色谱柱。通过对苯类混合物和醇类混合物进行分离,考察了其分离性能。

  15. Highly selective CO2 adsorption accompanied with low-energy regeneration in a two-dimensional Cu(II) porous coordination polymer with inorganic fluorinated PF6(-) anions.

    Science.gov (United States)

    Noro, Shin-ichiro; Hijikata, Yuh; Inukai, Munehiro; Fukushima, Tomohiro; Horike, Satoshi; Higuchi, Masakazu; Kitagawa, Susumu; Akutagawa, Tomoyuki; Nakamura, Takayoshi

    2013-01-01

    High selectivity and low-energy regeneration for adsorption of CO(2) gas were achieved concurrently in a two-dimensional Cu(II) porous coordination polymer, [Cu(PF(6))(2)(4,4'-bpy)(2)](n) (4,4'-bpy = 4,4'-bipyridine), containing inorganic fluorinated PF(6)(-) anions that can act as moderate interaction sites for CO(2) molecules.

  16. Mg(PF6)2-Based Electrolyte Systems: Understanding Electrolyte-Electrode Interactions for the Development of Mg-Ion Batteries.

    Science.gov (United States)

    Keyzer, Evan N; Glass, Hugh F J; Liu, Zigeng; Bayley, Paul M; Dutton, Siân E; Grey, Clare P; Wright, Dominic S

    2016-07-20

    Mg(PF6)2-based electrolytes for Mg-ion batteries have not received the same attention as the analogous LiPF6-based electrolytes used in most Li-ion cells owing to the perception that the PF6(-) anion decomposes on and passivates Mg electrodes. No synthesis of the Mg(PF6)2 salt has been reported, nor have its solutions been studied electrochemically. Here, we report the synthesis of the complex Mg(PF6)2(CH3CN)6 and its solution-state electrochemistry. Solutions of Mg(PF6)2(CH3CN)6 in CH3CN and CH3CN/THF mixtures exhibit high conductivities (up to 28 mS·cm(-1)) and electrochemical stability up to at least 4 V vs Mg on Al electrodes. Contrary to established perceptions, Mg electrodes are observed to remain electrochemically active when cycled in the presence of these Mg(PF6)2-based electrolytes, with no fluoride (i.e., MgF2) formed on the Mg surface. Stainless steel electrodes are found to corrode when cycled in the presence of Mg(PF6)2 solutions, but Al electrodes are passivated. The electrolytes have been used in a prototype Mg battery with a Mg anode and Chevrel (Mo3S4)-phase cathode. PMID:27359196

  17. Photoinduced electron and energy transfer from coumarin 153 to perylenetetracarboxylic diimide in bmimPF6/TX-100/water microemulsions.

    Science.gov (United States)

    Wu, Haixia; Wang, Haixia; Xue, Lin; Li, Xiyou

    2011-01-15

    A perylenetetracarboxylic diimide (PDI) compound with an attached hydrophilic polyoxyethylene group at the imide nitrogen position was designed and synthesized. Photoinduced electron and energy transfer between coumarin 153 (C-153) and PDI in a ternary microemulsion with an ionic liquid (bmimPF(6)/TX-100/H(2)O) were investigated by steady state electronic absorption and fluorescence spectroscopy. The results revealed that both PDI and C-153 resided at the interface between the surfactant TX-100 and the ionic liquid bmimPF(6) in the ternary microemulsions. The absorption spectra suggested no interactions between C-153 and PDI in the ground states, but the fluorescence spectra revealed the presence of an efficient electron transfer and a less efficient energy transfer from C-153 to PDI. Moreover, the electron transfer was much more efficient in microemulsions than that in homogeneous conventional organic solvents due to the unique micro-environment of the microemulsion. PMID:20965513

  18. Direct measurement of the chemical reactivity of silicon electrodes with LiPF6-based battery electrolytes.

    Science.gov (United States)

    Veith, Gabriel M; Baggetto, Loïc; Sacci, Robert L; Unocic, Raymond R; Tenhaeff, Wyatt E; Browning, James F

    2014-03-21

    We report the first direct measurement of the extent of the spontaneous non-electrochemically driven reaction between a lithium ion battery electrode surface (Si) and a liquid electrolyte (1.2 M LiPF6-3 : 7 wt% ethylene carbonate : dimethyl carbonate). This layer is estimated to be 35 Å thick with a SLD of ∼ 4 × 10(-6) Å(-2) and likely originates from the consumption of the silicon surface. PMID:24513965

  19. Dielectric spectroscopy study on ionic liquid microemulsion composed of water, TX-100, and BmimPF6

    Science.gov (United States)

    Chen, Zhen; Nozaki, Ryusuke

    2012-06-01

    We report here a broadband dielectric spectroscopy study on an ionic liquid microemulsion (ILM) composed of water, Triton X-100 (TX-100), and 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6). It is found that the phase behavior of this ILM can be easily identified by its dielectric response. The dielectric behavior of the ILM in the GHz range is consistent with that of TX-100/water mixtures with comparable water-to-TX-100 weight ratio. It consists of the relaxations due to ethylene oxide (EO) unit relaxation, hydration water dynamics, and/or free water dynamics. The water content dependence of the EO unit relaxation suggests that this relaxation involves dynamics of hydration water molecules. In the IL-in-water microemulsion phase, it is found that bmimPF6 molecules are preferentially dissolved in water when their concentration in water is lower than the solubility. An additional dielectric relaxation that is absent in the TX-100/water mixtures is observed in the frequency range of 107-108 Hz for this ILM. This low-frequency relaxation is found closely related to the bmimPF6 molecule and could be attributed to the hopping of its cations/anions between the anionic/cationic sites.

  20. Characterization of BF4− in terms of its effect on water by the 1-propanol probing methodology

    DEFF Research Database (Denmark)

    Morita, Takeshi; Ayako, Nitta; Nishikawa, Keilo;

    2014-01-01

    characterized as an amphiphile with weak hydrophobic and moderate hydrophilic contributions. These results were plotted on a two-dimensional map with hydrophobicity and hydrophilicity axes, H2O defining the origin. The melting point of 1-ethyl-3-methylimidazoliumtetrafluoroborate ([C2mim]BF4) was found within...... the trend that the larger the hydrophobicity and the hydrophilicity of the chosen counter anion, the lower the melting point of the resulting RTIL made of [C2mim]+ cation and the chosen anion. For the 1-butyl-3-methylimidazolium ([C4mim]+) based RTILs, however, redetermination of the melting point...

  1. Theoretical study on reaction of [(Ind ∗)Rh(CO) 2Me]BF 4 with nbd

    Science.gov (United States)

    Bi, Siwei; Wang, Bin; Zhao, Yi; Zhang, Zhenwei; Zhu, Shufen

    2006-07-01

    The mechanisms on the model reaction of [(Ind)Rh(CO) 2Me]BF 4 with nbd have been studied using density functional theory. Two pathways are proposed due to the rotation of indenyl group. Our results of calculations predict that the methyl migration is the rate-determining step, and that the rotation of indenyl group around the Rh-indenyl axis plays an important role in lowering the reaction barrier. Theoretical studies also reveal that this kind of reaction is favorable thermodynamically as a result of the relief of ring strain as nbd coordinating to the metal center and the chelation effect arisen from the cyclometallation.

  2. Effect of ZrO2 on conductivity of PVC–PMMA–LiBF4–DBP polymer electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; T Uma

    2000-02-01

    The preparation and characterization of composite polymer electrolytes of PVC–PMMA–LiBF4–DBP for different concentrations of ZrO2 have been investigated. FTIR studies indicate complex formation between the polymers, salt and plasticizer. The electrical conductivity values measured by a.c. impedance spectroscopy is found to depend upon the ZrO2 concentration. The temperature dependence of the conductivity of the polymer films seems to obey the VTF relation. The conductivity values are presented and results discussed.

  3. Experiments and model for the surface tension of (MDEA + [Bmim][BF4]) and (MDEA + [Bmim][Br]) aqueous solutions

    International Nuclear Information System (INIS)

    Highlights: • The surface tensions of (MDEA + ionic liquids) aqueous solutions were measured. • The experiments were modeled satisfactorily by using a thermodynamic equation. • The temperature dependence of the surface tension was illustrated. • The effects of the mass fractions of MDEA and ionic liquids were demonstrated. -- Abstract: The surface tension (γ) of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), 1-butyl-3-methylimidazolium bromide ([Bmim][Br]), (N-methyldiethanolamine(MDEA) + [Bmim][BF4]) and (MDEA + [Bmim][Br]) aqueous solutions were measured by using the BZY-1 surface tension meter. The temperature ranged from (293.2 to 323.2) K. The mass fraction of MDEA ranged from 0.35 to 0.45. A thermodynamic equation was proposed to model the surface tension of (MDEA + ionic liquids) (ILS) aqueous solutions and the calculated results agreed well with the experiments. The effects of temperature, mass fractions of MDEA and ILS on the surface tension were demonstrated on the basis of experiments and calculations

  4. Thermal properties of [Cr(NH3)6](BF4)3 studied by adiabatic and relaxation calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Four solid phase transitions are observed between T = (9 and 300) K for [Cr(NH3)6](BF4)3. • Low temperature properties were investigated with relaxation calorimetry below T = 20 K. • For nonzero values of applied magnetic field well-defined Schottky anomaly appears. • Isothermal magnetization curve recorded up to 5 T was measured at T = 1.8 K. - Abstract: Four (solid–solid) phase transitions were detected in the temperature range of (9 to 300) K in polycrystalline [Cr(NH3)6](BF4)3 at TC1 = 240.7 K, TC2 = 108.0 K, TC3 = 91.9 K, and TC4 = 61.3 K by adiabatic calorimetry. The measurements by relaxation calorimetry were followed on lowering temperature from 20 K down to 0.35 K under six different external magnetic field values (9, 7, 5, 3, 1 and 0) T. For non-zero values of applied magnetic field well-defined Schottky anomaly appears. Magnetic heat capacity was calculated assuming the zero-field splitting for the decoupled Cr(III) ions. There is no discrepancy between the observed and calculated values. Isothermal magnetization curve recorded up to 5 T was measured at temperature of 1.8 K

  5. Dielectric spectroscopy study on ionic liquid microemulsion composed of water, TX-100, and BmimPF6

    OpenAIRE

    Chen, Zhen; Nozaki, Ryusuke

    2012-01-01

    We report here a broadband dielectric spectroscopy study on an ionic liquid microemulsion (ILM) composed of water, Triton X-100 (TX-100), and 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6). It is found that the phase behavior of this ILM can be easily identified by its dielectric response. The dielectric behavior of the ILM in the GHz range is consistent with that of TX-100/water mixtures with comparable water-to-TX-100 weight ratio. It consists of the relaxations due to ethylene o...

  6. A molecular dynamics simulation of the structure of ionic liquid (BMIM+/PF-6)/rutile (110)interface

    Institute of Scientific and Technical Information of China (English)

    WANG Shu; CAO Zhen; LI Shu; YAN TianYing

    2009-01-01

    The interfacial structure between the room-temperature ionic liquid,1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIM+/PF6-) and rutile (110) surface is simulated by classical molecular dynamics simulation,aiming to model a crucial constituent of the electrolyte/semiconductor interface.The simulation results show several enhanced layers forming in the interfacial region,especially for the anions.A well ordered double layering structure of the ions is also observed in the interfacial region.The cations are found to organize themselves in a parallel alignment with respect to the TiO2 slab,with an obvious elongation of the side chains.

  7. The Chlamydomonas PF6 Locus Encodes a Large Alanine/Proline-Rich Polypeptide That Is Required for Assembly of a Central Pair Projection and Regulates Flagellar Motility

    OpenAIRE

    Rupp, Gerald; O'Toole, Eileen; Porter, Mary E.

    2001-01-01

    Efficient motility of the eukaryotic flagellum requires precise temporal and spatial control of its constituent dynein motors. The central pair and its associated structures have been implicated as important members of a signal transduction cascade that ultimately regulates dynein arm activity. To identify central pair components involved in this process, we characterized a Chlamydomonas motility mutant (pf6-2) obtained by insertional mutagenesis. pf6-2 flagella ...

  8. Preparation and Molten Salt as Performances of Room Electrolyte carbon Capacitor Based on Trifluoroacetamide n CarbonLiPF6 and

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    A novel room moRen salt with an eutectic temperature of about -62℃ is prepared using LiPF6 and trifluoroacetamide as precursors. And then its performance is evaluated in carbon-carbon electrochemical double layerdifferent molar ratios are characterized and then the liquid-solid phase diagram is presented. The electrochemical performance tests show that the as-prepared LiPF6/trifluoroacetamide molten salt is a promising electrolyte candidate for carboncarbon EDLCs.

  9. Studies on structural, thermal and AC conductivity scaling of PEO-LiPF6 polymer electrolyte with added ionic liquid [BMIMPF6

    Science.gov (United States)

    Chaurasia, S. K.; Saroj, A. L.; Shalu, Singh, V. K.; Tripathi, A. K.; Gupta, A. K.; Verma, Y. L.; Singh, R. K.

    2015-07-01

    Preparation and characterization of polymer electrolyte films of PEO+10wt.% LiPF6 + xwt.% BMIMPF6 (1-butyl-3-methylimidazolium hexafluorophosphate) containing dopant salt lithium hexafluorophosphate (LiPF6) and ionic liquid (BMIMPF6) having common anion PF6 - are reported. The ionic conductivity of the polymer electrolyte films has been found to increase with increasing concentration of BMIMPF6 in PEO+10 wt.% LiPF6 due to the plasticization effect of ionic liquid. DSC and XRD results show that the crystallinity of polymer electrolyte decreases with BMIMPF6 concentration which, in turn, is responsible for the increase in ionic conductivity. FTIR spectroscopic study shows the complexation of salt and/or ionic liquid cations with the polymer backbone. Ion dynamics behavior of PEO+LiPF6 as well as PEO+LiPF6 + BMIMPF6 polymer electrolytes was studied by frequency dependent conductivity, σ(f) measurements. The values σ(f) at various temperatures have been analyzed in terms of Jonscher power law (JPL) and scaled with respect to frequency which shows universal power law characteristics at all temperatures.

  10. Laser photolysis study of anthraquinone in binary mixtures ofionic liquid [bmim][PF6] and organic solvent

    Directory of Open Access Journals (Sweden)

    Side Yao

    2006-12-01

    Full Text Available Photochemical properties of the ionic liquid (RTIL 1-butyl-3-methylimidazoliumhexafluorophosphate [bmim][PF6] and its binary mixed solutions with organic solvent(DMF and MeCN were investigated by laser photolysis at an excitation wavelength of 355nm, using anthraquinone (AQ as a probe molecule. It was indicated that the triplet excitedstate of AQ (3AQ* can abstract hydrogen from [bmim][PF6]. Moreover, along with thechange of the ratio of RTIL and organic solvent, the reaction rate constant changes regularly.Critical points were observed at volume fraction VRTIL = 0.2 for RTIL/MeCN and VRTIL =0.05 for RTIL/DMF. For both systems, before the critical point, the rate constant increasesrapidly with increasing VRTIL; however, it decreases obviously with VRTIL after the criticalpoint. We conclude that the concentration dependence is dominant at lower VRTIL, while theviscosity and phase transformation are dominant at higher VRTIL for the effect of ionic liquidon the decay of rate constant.

  11. Synthesis and Crystal Structure of [CpRu(η5-C5H5)(dppc)Cl][PF6

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-Hua; YU Guang-Ao; MENG Xiang-Gao; CHEN Yan; REN Yong; LIU Sheng-Hua

    2006-01-01

    The title complex [Ru(η5-C5H5)(dppc)Cl][PF6] has been synthesized by the reaction of [Ru(η5-C5H5)(PPh3)2Cl] with [dppc][PF6] (1,1'-bis(diphenylphosphino)cobaltocenium hexaflurophospate) in CH2Cl2, and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 15.754(8), b =13.704(7), c=19.120(10) (A),β=106.148(9)°, V=3965(4) (A)3, Z=4, C40H35Cl3CoF6P3Ru, Mr=988.94, Dc=1.657 g/cm3, F(000) = 1984 and μ(MoKα) = 1.181 mm-1. The final R = 0.0425 and wR = 0.1001 for 7002 independent reflections. The title complex shows a mononuclear Ru(Ⅱ)capped by an η5-Cp ring, a chelating η2-dppc and a terminal chloride to assume a three-legged piano-stool configuration.

  12. Ultra-fast and sensitive photo-induced phase switching in (EDO-TTF)2PF6

    International Nuclear Information System (INIS)

    Organic conductor (EDO-TTF)2PF6 crystal having 14 filled band shows a metal (M)-insulator (I) transition accompanied with Peierls transition, charge ordering, and anion ordering at transition temperature, TC=280K. This crystal is an important and fascinating candidate for photo-induced M-I transition because the multi-instability will afford sensitivity to the tiny stimulation. We make the report of the reflectivity change in (EDO-TTF)2PF6 crystal induced by the irradiation of femto-second (fs) pulsed laser (pulse width: 120fs, main wavelength: 800nm, repetition rate: 1kHz). The obtained results indicate that the highly efficient I-to-M transition occurs within 3ps in this material. Based on these results, the strong electron-lattice cooperative interaction is proved to play an essential role in the driving process of this M-I transition. Also, 14 filled materials, which show M-I transition, accompanied with the charge ordering, can be classified as fascinating candidates not only for superconductivity but also for photo-induced cooperative phenomena and application in phase switching devices

  13. Ab initio studies on [bmim][PF6]–CO2 mixture and CO2 clusters

    Indian Academy of Sciences (India)

    B L Bhargava; M Saharay; S Balasubramanian

    2008-06-01

    Ab initio molecular dynamics studies have been carried out on the room temperature ionic liquid, 1,n-butyl,3-methylimidazolium hexafluorophosphate ([bmim][PF6]) and supercritical carbon dioxide mixture at room temperature and experimental density. Partial radial distribution functions (RDF) for different sites have been computed to see the organization of CO2 molecules around the ionic liquid. Several partial RDFs around the carbon atom of CO2 molecule are compared to find out that the CO2 has specific interaction with a carbon atom present in the imidazolium ring. The CO2 is also found to be very well organized around the terminal carbon atom of the butyl chain. The partial RDFs for the oxygen atoms around oxygen and carbon atoms of the CO2 suggests that there is very good organization of CO2 molecules around themselves even in the [bmim][PF6] – CO2 mixture. The instantaneous quadrupole moment tensor has been calculated for the anion and the cation. The ensemble average of diagonal components of quadrupole moment tensor of the cation have finite values, whereas the off-diagonal components of the cation and both the diagonal and off-diagonal components of the anion have the value of zero with a large standard deviation. The CPMD studies performed on CO2 clusters reveals the greater tendency of the clusters with more CO2 units, to deviate from the linear geometry.

  14. Isothermal and non-isothermal crystallization kinetics of PVA + ionic liquid [BDMIM][BF4]-based polymeric films

    Science.gov (United States)

    Saroj, A. L.; Chaurasia, S. K.; Kataria, Shalu; Singh, R. K.

    2016-06-01

    The effect of ionic liquid (IL), 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [BDMIM][BF4], on crystallization behavior of poly(vinyl alcohol) (PVA) has been studied by isothermal and non-isothermal differential scanning calorimetry techniques. The PVA + IL based polymer electrolyte films have been prepared using solution casting technique. To describe the isothermal and non-isothermal crystallization kinetics, several kinetic equations have been employed on PVA + IL based films. There is strong dependence of the peak crystallization temperature (Tc), relative degree of crystallity (Xt), half-time of crystallization (t1/2), crystallization rate constants (Avrami Kt and Tobin AT), and Avrami (n) and Tobin (nT) exponents on the cooling rate and IL loading.

  15. Effect of Hydrogen Reduction of Silver Ions on the Performance and Structure of New Solid Polymer Electrolyte PEI/Pebax2533/AgBF4 Composite Membranes

    Institute of Scientific and Technical Information of China (English)

    WANG Yanbei; REN Jizhong; LI Hui; DENG Maicun

    2013-01-01

    In this paper,the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer,PA12-PTMO)/AgBF4 composite membranes is investigated.For PEI/Pebax2533/AgBF4 composite membranes prepared with different AgBF4 concentration,the permeances of propylene and ethylene increase with the increase of AgBF4 concentration due to the carrier-facilitated transport,resulting in a high selectivity.But for propylene/propane mixture,the mixed-gas selectivity is lower than its ideal selectivity.The hydrogen reduction strongly influences the membrane performance,which causes the decrease of propylene permeance and the increase of propane permeance.With the increase of hydrogen reduction time,the membranes show a clearly color change from white to brow0n,yielding a great selectivity loss.The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ag after hydrogen reduction,and aggregated on the surface of PEI/Pebax2533/AgBF4 composite membranes.

  16. 月桂酸淀粉酯在[ BMIM ] BF4离子液体中的酶法合成%Synthesis of laurate starch through lipase-catalyzed reaction in [ BMIM] BF4 ionic liquid

    Institute of Scientific and Technical Information of China (English)

    袁久刚; 向中林; 范雪荣; 王强; 姚金龙; 唐文君; 于拥军

    2016-01-01

    为了改善淀粉的疏水性能,采用固定化脂肪酶CALB在[ BMIM] BF4离子液体中对淀粉进行了月桂酸酯化改性。首先,对反应后得到的产物结构进行了核磁分析,结果显示月桂酸在脂肪酶的催化作用下成功对淀粉进行了改性。其次,研究了不同因素对产物取代度的影响,结果表明月桂酸淀粉酯的较优制备条件为:脂肪酶用量0.2 g、月桂酸/AGU摩尔比=3∶1、反应温度60℃、反应时间4 h。最后,对月桂酸接枝后淀粉的疏水性能进行了测试,结果显示淀粉的润湿接触角明显提高,而且随着取代度的增加,疏水性也越高。%In order to improve the hydrophobilicity of raw starch , lauric acid was grafted on starch through CALB lipase-catalyzed reac-tion in [BMIM]BF4ionic liquid.Firstly, the structure of modified starch was tested with 1H NMR, it showed that the lauric acid was successfully grafted on starch .Secondly , the effect of different reaction conditions on the DS values of modified starch was studied in detail.Results showed that a better synthesis condition for laurate starch was as follows:lipase dosage 0.2 g, lauric acid/AGU=3:1, temperature 60℃,time 4 h.Finally, the hydrophobilicity of modified starch was tested through water contact angle .Results showed that the hydrophobicity of modified starch was significantly improved and increased with DS values .

  17. Microwave assisted synthesis of [BMIM]BF4 and application in the extraction of cefalexin%离子液体[BMIM]BF4的微波合成及其在萃取头孢氨苄中的应用

    Institute of Scientific and Technical Information of China (English)

    郭玄; 于雪荣; 李士阔; 张秀真; 沈玉华; 王阳

    2010-01-01

    本文在微波辐射条件下快速合成了亲水型离子液体1-丁基-3-甲基咪唑四氟硼酸盐BF4.在不到30min的反应时间内,[BMIM]BF4产率可达92%以上.同时,我们还探讨了[BMIM]BF4与MgSO4溶液形成的双水相体系对萃取头孢氨苄的影响.结果表明在[BMIM]BF4为6.85ml,MgSO4含量为3.53g时,所形成的双水相体系对头孢氨苄的萃取率可达97%以上.

  18. Electrochemical behavior of Ru(H2bpp)2(PF6)2 and its interaction with bovine serum albumin (BSA)

    Institute of Scientific and Technical Information of China (English)

    Qiao Hua Wei; Li Jing Han; Jing Hua Chen; Fang Nan Xiao; Shen Liang Zeng; Guo Nan Chen

    2011-01-01

    In this paper, it was found that Ru(H2bpp)2(PF6)2 (H2bpp = 2,6-bis(pyrazol-3-yl)pyridine) complex had excellent electrochemical activity at the carbon paste electrode in the buffer solution of Tris-HCl (pH 7.0) with a couple reversible redox peaks at 0.296 V and 0.348 V, respectively. Voltammetry was used to investigate the electrochemical behavior of Ru(H2bpp)2(PF6)2 and the interaction between Ru(H2bpp)2(PF6)2 and bovine serum albumin (BSA). In the present of BSA, the oxidation peak current of Ru(H2bpp)2(PF6)2 complex was decreased linearly and the decrease of oxidation peak current of Ru(H2bpp)2(PF6)2 is proportional to BSA concentration from 0.1 to 2.5 mg/L with a detection limit 0.02 mg/L.

  19. [BMIM] [BF4] ionic liquid assistance effect on the crystallinity and morphology of Sb2S3 nanostructures synthesized by ultrasound

    International Nuclear Information System (INIS)

    Unidimensional crystalline Sb2S3 nanostructures were successfully synthesized by ultrasound irradiation assisted with the ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]. The starting reagents were SbCl3, thioacetamide, absolute ethanol (AET), and the used ionic liquid was [BMIM][BF4]. The resultant materials were thermally annealed at 155 and 200 oC under controlled vacuum conditions. The experiments showed that IL assistance played a key role in the crystallinity and morphology of the obtained products. The resultant materials were characterized by powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray analysis (EDX). (author).

  20. NMR determination of the ordering of CH3NO2 co-intercalated with PF6-, AsF6-, or SbF6- in graphite

    International Nuclear Information System (INIS)

    Comparison of the intensities of the 19F and 1H NMR spectra of the graphite intercalation compound prepared by reaction of highly-oriented pyrolytic graphite with NO2PF6 dissolved in CH3NO2 showed that the number of CH3NO2 molecules present per PF6- ion varied from 1.64 to 1.14 depending upon sample preparation. The 1H NMR spectra of CH3NO2 in single pieces of HOPG intercalated with PF6-, AsF6-, or SbF6- show 1:2:1 triplets due to dipolar splittings resulting from partial ordering of the CH3NO2 molecules with the molecular symmetry axis parallel to the graphite planes. (Auth.)

  1. [PAMIM][PF6]离子液体作为气相色谱固定相的研究%Research of [PAMIM][PF6] ionic liquid as stationary phase for gas chromatography

    Institute of Scientific and Technical Information of China (English)

    郑建华; 申书昌; 陈光

    2013-01-01

    以1-甲基咪唑、氯丙烯、六氟磷酸钾为原料合成了一种聚合离子液体聚-1-丙烯基-3-甲基咪唑六氟磷酸盐([PAMIM][PF6]).通过红外光谱法和核磁共振波谱法表征了产物的结构,通过热重分析,考察了其分解温度,并确定了此离子液体作为气相色谱固定液的最高使用温度.以离子液体作为气相色谱固定相,制备了色谱填充柱,通过对烃系物、醇系物的分离,考察了色谱柱的分离效果、极性.%A kind of polymer ionic liquid which is called poly (l-allyl-3- methylimidazolium hexafluo-rophosphate) was synthesized using 1-methylimidazole, allyl chloride and hexafluorophosphate as raw meterials. The structure of the ionic liquid was characterized by IR and NMR. The maximum.operating of this ionic liquid temperature as gas chromatography stationary phase was confirmed by TGA The chromatography column was made of the ionic liquids and supporter .The separating character and polarity of the chromatography column were studied by the hydrocarbons and alcohols mixtures respectively.

  2. Molecular dynamics simulation of the electrochemical interface between a graphite surface and the ionic liquid [BMIM][PF6].

    Science.gov (United States)

    Kislenko, Sergey A; Samoylov, Igor S; Amirov, Ravil H

    2009-07-21

    The structure of the electrical double layer in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) near a basal plane of graphite was investigated by molecular dynamics simulation. The calculations were performed both for an uncharged graphite surface and for positively and negatively charged ones. It is found that near an uncharged surface the ionic liquid structure differs from its bulk structure and represents a well-ordered region, extending over approximately 20 A from the surface. Three dense layers of ca 5 A thick are clearly observed at the interface, composed of negative ions and positively charged rings. It is established that in the first adsorption layer the imidazolium ring in the [BMIM]+ cation tends to be arranged in parallel to the graphite surface at a distance of 3.5 A. The [PF6]- anion is oriented in such a way that the phosphorus atom is at a distance of 4.1 A from the surface and triplets of fluorine atoms form two planes parallel to the graphite surface. Ions adsorbed at the uncharged surface are arranged in a highly defective 2D hexagonal lattice and the corresponding lattice spacing is approximately four times larger than that of the graphene substrate. The influence of the electrode potential on the distribution of electrolyte ions and their orientation has also been investigated. Increase in the electrode potential induces broadening of the angle distribution of adsorbed rings and a shift of the most probable tilt angle towards bigger values. It was shown that there are no adsorbed anions on the negatively charged surface (sigma = -8.2 microC cm(-2)), but the surface concentration of adsorbed cations on the positively charged surface (sigma = +8.2 microC cm(-2)) has a nonzero value. In addition, the influence of the surface charge (+/- sigma) on the volume charge density and electric potential profiles in an electrolyte was studied. The differences in the cation and anion structure result in the fact that the

  3. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF6 electrolyte

    International Nuclear Information System (INIS)

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF6 non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g−1. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g−1 at a scan rate of 1 mV s−1

  4. Novel electrolyte mixtures based on dimethyl sulfone, ethylene carbonate and LiPF6 for lithium-ion batteries

    Science.gov (United States)

    Hofmann, Andreas; Hanemann, Thomas

    2015-12-01

    In this study, novel electrolyte mixtures for Li-ion cells are presented which are composed of ethylene carbonate/dimethyl sulfone (80:20 wt./wt.) as a solvent mixture and LiPF6, lithium bis(oxalato)borate and lithium difluoro(oxalato)borate as conducting salts. The main advantages of the solvent mixture are high flash points of >140 °C which enhance the intrinsic safety of Li-ion cells while maintaining good cell performance above 0-5 °C. The movability of the lithium ions in the electrolyte is investigated via programmed current derivative chronopotentiometry. It is found that pure electrolyte properties cannot necessarily predict the electrolyte behavior in real Li-ion cells but the complex interplay between electrolytes, electrode materials and separators has to be taken into account. Using the newly developed electrolytes, it is possible to achieve C-rates up to 1.5C with >80% of the initial specific discharge capacity (25 °C). Within 200 cycles during one month in cell tests (C||NMC) it is proven that the retention of the specific capacity is >98% of the third discharge cycle in dependence of the conducting salt.

  5. Enzymatic synthesis of phytosterol esters catalyzed by Candida rugosa lipase in water-in-[Bmim]PF6 microemulsion.

    Science.gov (United States)

    Zeng, Chaoxi; Qi, Suijian; Li, Zhigang; Luo, Riming; Yang, Bo; Wang, Yonghua

    2015-05-01

    A water-in-ionic liquid microemulsion ([Bmim]PF6/Tween20/H2O) was applied as reusable reaction medium to esterify phytosterols with fatty acid by Candida rugosa lipase (CRL) successfully. Two kinds of commercial CRLs, AY30 and AYS which cannot effectively catalyze esterification in conventional reaction system were found effective in the microemulsion system. Effects of reaction parameters on esterification were investigated; results showed that the conversion rate of 87.9 and 95.1 % was obtained in 24 and 48 h of reaction, respectively, under the optimized condition: the molar ratio of water to Tween 20 (w 0 value) at 5.4, Tween 20 at a concentration of 305 mM, 50 °C,pH 7.4, 10 % of enzyme loading (w/w, with respect to total reactants), and phytosterols/lauric acid molar ratio of 1:2. Moreover, by using n-hexane as the extraction agent, the lipase-encapsulated microemulsion could be reused at least seven times (>168 h) without significant changes in the conversion rate, while achieving a purpose of simple separation and purification. PMID:25575761

  6. 丙烯酰胺共聚物AM/AA/NCD-离子液[equin]BF4复合粘土稳定剂的合成及性能研究%Synthesis and evaluation of clay stabilizer based on copolymer AM/AA/NCD and ionic liquid[equin]BF4

    Institute of Scientific and Technical Information of China (English)

    蒋文超; 苟绍华; 胡海; 刘帅; 杨上艺; 罗源皓

    2014-01-01

    采用丙烯酰胺(AM)、丙烯酸(AA)以及单六位取代烯丙胺基β-环糊精(NCD)为原料,合成出了一种水溶性聚合物 AM/ AA/ NCD。采用喹啉、溴乙烷、氟硼酸钠在温和条件下合成了离子液体四氟硼酸1-乙基-喹啉盐([equin]BF4)。AM/ AA/ NCD 溶液与[ equin]BF4在50℃下回流,发生复合反应,生成 AM/ AA/ NCD-离子液[equin]BF4复合粘土稳定剂。考察了反应条件对聚合反应的影响,确立了最佳合成工艺。通过膨润土线性膨胀实验,确定了复合粘土稳定剂最佳加量为0.6%,防膨率达到81%。采用 X-射线衍射(XRD)考察了复合粘土稳定剂对钠蒙脱土晶层间距的抑制效果,晶层间距从1.89 nm 降低到1.66 nm。压入硬度实验表明,AM/ AA/ NCD-[equin]BF4能有效保持泥页岩岩石强度。%A novel copolymer AM/ AA/ NCD was prepared by acrylamide(AM),acrylic acid(AA)and mono-6-(allyl amino)-β-cyclodextrin(NCD). Ionic liquid[equin]BF4 was synthesized using quinolin, bromoethane and sodium fluoroborate(NaBF4 )as starting materials. AM/ AA/ NCD Solution and[equin] BF4 were mixed and refluxed at 50 ℃ for incorporation reaction yielding AM/ AA/ NCD-[ equin]BF4 as clay stabilizer. The structures of AM/ AA/ NCD and[ equin]BF4 were confirmed by Infrared( IR) spectroscopy. The anti-swelling ratio could be 81% when the concentration of clay stabilizer was 0. 6% . The result of X-ray diffractometry(XRD)test showed that the solutions of obtained copolymers could re-markably reduce the interlayer spacing of sodium montmorillonite(from 1. 89 nm to 1. 66 nm)and im-prove the indentation hardness of shale.

  7. Molecular dynamics simulations of the aqueous interface with the [BMI][PF6] ionic liquid: Comparison of different solvent models.

    Science.gov (United States)

    Chevrot, G; Schurhammer, R; Wipff, G

    2006-09-28

    We report a Molecular Dynamics (MD) study of the interface between water and the hygroscopic room temperature Ionic Liquid "IL" [BMI][PF6] (1-butyl-3-methyl-imidazolium hexafluorophosphate), comparing the TIP3P, SPC/E and TIP5P models for water and two IL models where the ions are +/-1 or +/-0.9 charged. A recent MD study (A. Chaumont, R. Schurhammer and G. Wipff, J. Phys. Chem. B, 2005, 109, 18964) showed that using TIP3P water in conjunction with the IL(+/-1) model led to water-IL mixing without forming an interface, whereas a biphasic system could be obtained with the IL(+/-0.9) model. With the TIP5P and SPC/E models, the juxtaposed aqueous and IL phases are found to remain distinct for at least 20 ns. The resulting IL humidity, exaggerated with the IL(+/-1) model, is in better agreement with experiment using the IL(+/-0.9) model. We also report demixing simulations on the "randomly mixed" liquids, using the IL(+/-0.9) model for the ionic liquid. With the three tested water models, the phases separate very slowly ( approximately 20 ns or more) compared to "classical" chloroform-water mixtures (less than 1 ns), leading to biphasic systems similar to those obtained after equilibration of the juxtaposed liquids. The characteristics of the interface (size, polarity, ion orientation, electrostatic potential) are compared with the different models. Possible reasons why, among the three tested water models, the widely-used TIP3P model exaggerates the inter-solvent mixing, are analyzed. The difficulty in computationally and experimentally equilibrating water-IL mixtures is attributed to the slow dynamics and micro-heterogeneity of the IL and to the different states of water in the IL phase.

  8. Synthesis and structures of novel octadecanuclear clusters [Cu12RE6(μ3-OH)24(pyb)12(H2O)18(μ12-ClO4)]17+(RE=Sm, Eu)

    Institute of Scientific and Technical Information of China (English)

    陈小明; 吴玉銮; 王如骥

    1996-01-01

    The novel octadecanudear Cu-RE cluster haw been isolated from the reaction system of aqueous Cu2+-RE3+-pyb (RE=Sm, Eu; pyb=pyridine betaine) and characterized by single-crystal structural analysis. The results show that the clusters comprise a [Cu12RE6(μ3-OH)24(μ12-ClO4)]17+ octahedral core, which encapsulates a ClO4- ion and has 18 water molecules and 12 bridging pyb carboxylato ligands as external ligands.

  9. Physicochemical properties and electrochemical performance of [ Pmim ] [ ClO4 ] ionic liquid electrolyte in supercapacitor%[ Pmim ][ ClO4]电解质的物化性质及其在超级电容器中的性能研究

    Institute of Scientific and Technical Information of China (English)

    武宣宇; 李美超; 张鑫源; 张庆国

    2015-01-01

    A novel ionic liquid 1 -Pentyl -3 -methylimidazolium perchlorate salts ([ Pmim] ClO4 ) was synthesized by two -steps method .The density , surface tension , and electrical conductivity of the ionic liquid were investigated in different temperatures .A supercapacitor composed of the activated carbon electrode and the [ Pmim] ClO4 electrolyte was prepared .The electrochemical performance of the supercapacitor was studied by cy-clic voltammograms, alternating current resistance , and constant current charge -discharge tests, respectively. The results showed that the density and the surface tension of [ Pmim] ClO4 decreased with the increase of tem-perature.The working voltage window of the supercapacitor reached to 5.0 V.Moreover, the capacitor possessed typical capacitance characteristic , good reversibility , and better cycleability , which showed a great potential of this ionic liquid electrolyte in supercapacitor applications .%采用两步法设计合成了一种新型离子液体电解质(液)1-戊基-3-甲基咪唑高氯酸盐([ Pmim][ ClO4]),对这种电解质的密度、表面张力、电导率等物化性质进行了测定.并将其与活性炭电极组装成超级电容器,通过交流阻抗、循环伏安及恒流充放电等测试手段对其电化学性能进行了研究.测试结果表明,该离子液体的密度和表面张力都随温度升高而减小,超级电容器的电化学窗口可以达到5.0 V,并且具有良好的电容特性、可逆性及循环特性,是一种具有应用潜力的超级电容器电解液.

  10. Extraction of penicillin G by aqueous two-phase system of [Bmim]BF4/NaH2PO4

    Institute of Scientific and Technical Information of China (English)

    LIU Qingfen; HU Xuesheng; WANG Yuhong; YANG Ping; XIA Hansong; YU Jiang; LIU Huizhou

    2005-01-01

    A novel approach for the extraction of penicillin G by aqueous two-phase system comprised of hydrophilic ionic liquid [Bmim]BF4 (1-butyl-3- methylimidazolium tetrafluoroborate) and NaH2PO4 is reported. The effects of some important parameters involving the concentration of NaH2PO4, the concentration of penicillin G, the amount of [Bmim]BF4 on the formation of aqueous two-phase system and the extraction yield of penicillin were investigated. The primary result shows that the ATPS can take advantage of penicillin concentrated in upper phase at higher pH value for penicillin extraction from its aqueous solution without emulsification.

  11. Lithium difluoro(oxalate)borate and LiBF4 blend salts electrolyte for LiNi0.5Mn1.5O4 cathode material

    Science.gov (United States)

    Zhou, Hongming; Xiao, Kaiwen; Li, Jian

    2016-01-01

    The electrochemical behaviors of lithium difluoro(oxalate)borate (LiODFB) and LiBF4 blend salts in ethylene carbonate + dimethyl carbonate + ethyl(methyl) carbonate (EC + DMC + EMC, 1:1:1, by wt.) have been investigated for LiNi0.5Mn1.5O4 cathode in lithium-ion batteries. The electric conductivity tests are utilized to examine the relationship among solution conductivity, the electrolyte composition and temperature. Through cyclic voltammetry, charge-discharge test and AC impedance measurements, we compare the capacity and cycling efficiency of LNMO cathode in different electrolyte systems at different temperatures and discharge current rates. Scanning electron microscopy (SEM) analysis and X-ray photoelectron spectroscopy (XPS) are served to analyze the surface nature of LNMO cathode after cycles at elevated temperature. These results demonstrate that LNMO cathode can exert excellent electrochemical performance with the increase of LiODFB concentration at room temperature and elevated temperature and it is found that just slight LiBF4, mixed with LiODFB as blend salts, can strikingly improve the cyclability at -20 °C, especially in high-rate cycling. Grouped together, the optimum LiODFB/LiBF4 molar ratio is around 4:1, which can present an excellent affinity to LNMO cathode in a wide electrochemical window.

  12. Studies on the micropolarities of bmimBF4/TX-100/toluene ionic liquid microemulsions and their behaviors characterized by UV-visible spectroscopy.

    Science.gov (United States)

    Li, Na; Gao, Yan'an; Zheng, Liqiang; Zhang, Jin; Yu, Li; Li, Xinwei

    2007-01-30

    Ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4), were substituted for polar water and formed nonaqueous microemulsions with toluene by the aid of nonionic surfactant TX-100. The phase behavior of the ternary system was investigated, and microregions of bmimBF4-in-toluene (IL/O), bicontinuous, and toluene-in-bmimBF4 (O/IL) were identified by traditional electrical conductivity measurements. Dynamic light scattering (DLS) revealed the formation of the IL microemulsions. The micropolarities of the IL/O microemulsions were investigated by the UV-vis spectroscopy using the methyl orange (MO) and methylene blue (MB) as absorption probes. The results indicated that the polarity of the IL/O microemulsion increased only before the IL pools were formed, whereas a relatively fixed polar microenvironment was obtained in the IL pools of the microemulsions. Moreover, UV-vis spectroscopy has also shown that ionic salt compounds such as Ni(NO3)2, CoCl2, CuCl2, and biochemical reagent riboflavin could be solubilized into the IL/O microemulsion droplets, indicating that the IL/O microemulsions have potential application in the production of metallic or semiconductor nanomaterials, and in biological extractions or as solvents for enzymatic reactions. The IL/O microemulsions may have some expected effects due to the unique features of ILs and microemulsions. PMID:17241018

  13. Densities and Viscosities of 1-butyl-3-methylimidazolium Hexafluorophosphate [bmim][PF6]+CO2 Binary System:Determination and Correlation

    Institute of Scientific and Technical Information of China (English)

    乔燕; 闫方友; 夏淑倩; 马沛生

    2013-01-01

    A gas-dissolving device was designed and connected to the falling-body viscometer, which was used to determine the viscosities of liquids in our lab before. The equipment can be used to determine the gas composition, the densities and viscosities of the solution at the same time. The densities and viscosities of [bmim][PF6]+CO2 binary system were determined in the temperature range of 313.2 to 413.2 K and pressure range of 5.0 to 25.0 MPa by the equipment. Then the viscosities of [bmim][PF6]+CO2 binary system at constant temperature, constant pres-sure, and different temperature and pressure were correlated, respectively. For the correlation at different tempera-ture and different pressure for different concentration mixtures the average relative deviation ARD is 0.037.

  14. Pd nanoparticles immobilized in [bmim][PF6] supported on laponite clay as highly recyclable catalysts for the Mizoroki-Heck reaction

    OpenAIRE

    Martínez, Alejandro V.; Mayoral, José A.; García, José I.

    2014-01-01

    Mizoroki-Heck cross-couplings of aryl halides catalyzed by highly active palladium nanoparticles, immobilized on [bmim][PF6] films supported on laponite clay, have been investigated. The reactions are performed at 100 °C in solventless conditions to afford the corresponding coupling products in good to excellent yields under non-anhydrous and non-degassed conditions. Highly recoverable catalytic systems have been prepared, allowing up to 17 catalytic cycles with good yields and excellent sele...

  15. Synthesis of Polypyrrole Inverse Opal in [bmim]PF6- Containing Acetonitrile and the Application of the Inverse Opal in Cell Prototype

    Directory of Open Access Journals (Sweden)

    Wei Yan

    2013-01-01

    Full Text Available Most primary cells use Zn or Li as the anode, a metallic oxide as the cathode, and an acidic or alkaline solution or moist past as the electrolytic solution. In this paper, highly ordered polypyrrole (PPy inverse opals have been successfully synthesized in the acetonitrile solution containing [bmim]PF6. PPy films were prepared under the same experimental conditions. Cyclic voltammograms of the PPy film and the PPy inverse opal in neutral phosphate buffer solution (PBS were recorded. X-ray photoelectron spectroscopy technique was used to investigate the structural surface of the PPy films and the PPy inverse opals. It is found that the PF6- anions kept dedoping from the PPy films during the potential scanning process, resulting in the electrochemical inactivity. Although PF6- anions also kept dedoping from the PPy inverse opals, the PO43- anions from PBS could dope into the inverse opal, explaining why the PPy inverse opals kept their electrochemical activity. An environmental friendly cell prototype was constructed, using the PPy inverse opal as the anode. The electrolytes in both the cathodic and anodic half-cells were neutral PBSs. The open-circuit potential of the cell prototype reached 0.487 V and showed a stable output over several hundred hours.

  16. Molecular dynamics simulation of the interfacial structure of [C(n)mim][PF6] adsorbed on a graphite surface: effects of temperature and alkyl chain length.

    Science.gov (United States)

    Dou, Q; Sha, M L; Fu, H Y; Wu, G Z

    2011-05-01

    The structures and diffusion behaviors of a series of ionic liquids [C(n)mim][PF(6)] (n = 1, 4, 8 and 12) on a graphite surface have been investigated by means of molecular dynamics simulation. It was found that three or four ordering layers of ionic liquids were formed near the graphite surface, and this layering structure was stable over the temperature range investigated. At the liquid/vacuum interface, the ionic liquid with a butyl chain had a monolayer ordering surface, while [C(8)mim][PF(6)] and [C(12)mim][PF(6)] exhibited a bilayer ordering with a polar domain sandwiched between two orientational nonpolar domains. More impressively, the simulated results showed that for the ionic liquids with alkyl chains longer than C(4), the adjacent alkyl chains in the whole film tended to be parallel to each other, with the imidazolium rings packed closely together. This indicated that the ionic liquids have a better regulated short-range structure than was previously expected. It was also found that both in the bottom layer and in the bulk region, the diffusion of the alkyl chains was much faster than that of the polar groups. However, as the alkyl chain length increased, the charge delocalization in the cation and the enhanced van der Waals interaction between the nonpolar groups contributed by reducing this difference in the diffusivity of major groups.

  17. Synthesis and Crystal Structure of Dinuclear Cadmium Complex [Cd2(phen)4(fca)2](ClO4)2·(H2O)2

    Institute of Scientific and Technical Information of China (English)

    YANG Jia-Xiang; ZHANG Ze; WU Jie-Ying; TIAN Yu-Peng; DU Peng; LIU Qing-Liang; FUN Hoong Kun; C. Suchada

    2003-01-01

    A novel complex [Cd2(phen)4(fca)2](ClO4)2((H2O)2 (fca = dianion of 3-ferrocenyl- 2-crotonic acid, phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray single-crystal structure analysis. It crystallizes in triclinic system, space group Pī with a = 11.6297(5), b = 12.5165(5), c = 13.8986(6) A, α = 63.345(1), β = 87.747(1), γ = 71.862(1)°, V = 1706.20(1) A3, Z = 1, Dc = 1.673 g/cm3, F(000) = 868 and μ(MoKα) = 1.185 mm-1 (λ = 0.71073 A). R = 0.0800 and Wr = 0.1793 for 7653 observed reflections (I > 2σ(I)). The structure consists of a dinuclear cation [Cd2(phen)4(fca)2]2+, two discrete perchlorate anions and two water molecules. The cationic part of the complex shows a tetrametallic core in which two fca groups act as the (O, O') bridging ligands between two cadmium(Ⅱ) ions with a distorted octahedral environment. The Cd…Cd intradimer distance is 4.128 A.

  18. Crystal structures and magnetic properties of the honeycomb-lattice antiferromagnet M2(pymca)3(ClO4), (M = Fe, Co, Ni)

    Science.gov (United States)

    Honda, Zentaro; Kodama, Takafumi; Hagiwara, Masayuki; Kida, Takanori; Okutani, Akira; Sakai, Masamichi; Fukuda, Takeshi; Kamata, Norihiko

    2016-09-01

    We report on the syntheses, crystal structures, and magnetic properties of a series of transition metal coordination polymers M2(pymca)3(ClO4), (pymca = pyrimidine-2-carboxylic acid, M = Fe (1), Co (2), and Ni (3)). These compounds are found to crystallize in a trigonal crystal system, space group P31m, with the lattice constants a = 9.727 Å and c = 5.996 Å for 1, a = 9.608 Å and c = 5.996 Å for 2, and a = 9.477 Å and c = 5.958 Å for 3 at room temperature. In these compounds, each pymca ligand connects to two M2+ ions, forming a honeycomb network in the ab plane. The temperature dependences of magnetic susceptibilities in these compounds show broad maxima, indicating antiferromagnetic interactions within two-dimensional honeycomb layers. We also observed an antiferromagnetic phase transition at low temperatures by magnetic susceptibility and heat capacity measurements. From the crystal structures and magnetic properties, we conclude that the compounds 1, 2, and 3 are good realizations of honeycomb-lattice antiferromagnets.

  19. Thermopower and specific heat of the organic molecular salt (TMTSF)(2)ClO(4): observation of the narrow band response.

    Science.gov (United States)

    Sun, Cheng-Hai; Yang, Hong-Shun; Liu, Jian; Gao, Hui-Xian; Wang, Jian-Bin; Cheng, Lu; Cao, Lie-Zhao; Lasjaunias, J C

    2008-06-11

    Measurements of thermopower S(a)(T) along the highly conducting a axis and specific heat of the Bechgaard salts (TMTSF)(2)ClO(4) for various cooling rates through the anion ordering temperature T(a) = 24 K were carried out. Sign reversal in S(a)(T) is found below T(a) and it decreases with increasing cooling rate, which is attributed to the change of a narrow band filling level as the temperature and the cooling rates change. The crossover from 2D to 3D in S(a)(T) is observed around 15 K. The onset temperature of anion ordering in S(a)(T) decreases from 29.8 to 24.2 K as the cooling rate increases. Meanwhile, the electronic specific heat coefficient γ has a pronounced change within this temperature region, giving strong evidence for a narrow band contribution. The difference in the specific heat between the quenched and relaxed states follows a T-cubic law from 5 to 24 K, implying a lattice distortion by the ordered anion only. The entropy estimated from the specific heat peak between 28 and 15 K is Rln (4/3) lower than the value Rln2, consistent with the thermopower result that some anions have been ordered far above T(a) for the relaxed state. PMID:21694314

  20. LiPF6/LiBOB混合锂盐改善LiFePO4/石墨动力电池高温循环性能研究%Use of LiPF6/LiBOB blend salt for improving cycling performances of LiFePO4/graphite battery at elevated temperature

    Institute of Scientific and Technical Information of China (English)

    宋海申; 赖延清; 李劼; 刘业翔; 张治安

    2013-01-01

    分别以 LiPF6、LiBOB 和 LiPF6/LiBOB 混合盐为电解质,研究了不同电解液对 LiFePO4/石墨动力电池高温循环性能的影响。结果表明,LiBOB 盐抑制了正极溶铁行为,并提高了正极高温循环充放电效率;由于 LiBOB基电解液对正极的保护及在负极表面良好的成膜作用,使得LiFePO4/石墨电池高温循环性能得到明显改善,但是增大了电池阻抗。LiPF6/Li-BOB混合盐可以发挥 LiBOB盐的优点增加正极稳定性,在石墨表面形成致密的 SEI 膜并能够有效改善电池高温循环性能,同时避免了单纯使用 LiBOB盐时阻抗较高的缺点。使用 LiPF6/LiBOB 混合盐,利用LiPF6盐低阻抗特性及 LiBOB盐对正、负电极的保护作用,可以有效提高电池电化学性能。%LiPF6 ,LiBOB and LiPF6/LiBOB blend salt-based electrolytes were investigated for improving cycling performances of LiFePO4/graphite lithium-ion batteries at elevated temperature.It was demonstrated that dis-solution of Fe from LiFePO4 was depressed in LiBOB based electrolyte,and columbic efficiency of LiFePO4/Li cell at elevated temperature was increased;LiBOB was reduced earlier on anode surface,forming compact SEI layer;and the capacity retention of LiFePO4/graphite cells at 55℃ increases with LiBOB concentration due to protective depositions of LiBOB on cathode surface and the SEI layer on anode surface,while the impedance of the cell is increased.LiPF6/LiBOB blend salt-based electrolyte combines the advantages of the different salts and maximizes the performance of cells.When electrolytes with LiPF6/LiBOB blend salt was used,the LiFe-PO4/graphite cells have excellent capacity retention at 55℃,while the impedance was dramatically decreased.

  1. Visible Light Driven Photocascade Catalysis: Ru(bpy)3(PF6)2/TBHP-Mediated Synthesis of Fused β-Carbolines in Batch and Flow Microreactors.

    Science.gov (United States)

    Chandrasekhar, D; Borra, Satheesh; Nanubolu, Jagadeesh Babu; Maurya, Ram Awatar

    2016-06-17

    1,2,3,4-Tetrahydro-β-carbolines were coupled with α-keto vinyl azides through an unprecedented visible light-Ru(bpy)3(PF6)2/TBHP mediated photocascade strategy that involves photosensitization, photoredox catalysis and [3 + 2] cycloaddition reaction. The scope and scale-up feasibility of the photocascade strategy was demonstrated by synthesizing 18 different fused β-carbolines in moderate to good yields using batch and continuous flow microreactor. This operationally simple synthetic protocol allows the formation of one C-C and two C-N new bonds in the overall transformation. PMID:27226119

  2. A molecular dynamics simulation of the structure of ionic liquid (BMIM+/PF6-)/rutile (110) interface

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The interfacial structure between the room-temperature ionic liquid, 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIM+/PF6-) and rutile (110) surface is simulated by classical molecular dynam-ics simulation, aiming to model a crucial constituent of the electrolyte/semiconductor interface. The simulation results show several enhanced layers forming in the interfacial region, especially for the anions. A well ordered double layering structure of the ions is also observed in the interfacial region. The cations are found to organize themselves in a parallel alignment with respect to the TiO2 slab, with an obvious elongation of the side chains.

  3. Cyclic voitammetry, convolutive voltammetry, chrono-potentiometry and digital simulation studies of [Pt(C≡C tol)_2(dppm)_2Ir(CO)_2]~+PF_6~- complex

    Institute of Scientific and Technical Information of China (English)

    El-Hallag S Ibrahim

    2009-01-01

    The electrochemical behaviour of the heterobimetallic complex [Pt(C≡C tol)_2(dppm)_2-Ir(CO)_2]~+PF_6~-was studied via cyclic voltammetry, convolutive voltammetry and chronopotentiometry at glassy carbon electrode in dichloromethane solution. The electrochemical parameters calculated from experimental data were tested and confirmed by matching the experimental cyclic voltammograms with the simu-lated data. It was found that convolutive voltammetry provided higher sensitivity, better resolution and more accurate method for determination of the electrochemical parameters than ordinary cyclic volt-ammetry.

  4. Interaction of ionic liquid with water with variation of water content in 1-butyl-3-methyl-imidazolium hexafluorophosphate ([bmim][PF6])/TX-100/water ternary microemulsions monitored by solvent and rotational relaxation of coumarin 153 and coumarin 490

    Science.gov (United States)

    Seth, Debabrata; Chakraborty, Anjan; Setua, Palash; Sarkar, Nilmoni

    2007-06-01

    The interaction of water with room temperature ionic liquid (RTIL) [bmim][PF6] has been studied in [bmim][PF6]/TX-100/water ternary microemulsions by solvent and rotational relaxation of coumarin 153 (C-153) and coumarin 490 (C-490). The rotational relaxation and average solvation time of C-153 and C-490 gradually decrease with increase in water content of the microemulsions. The gradual increase in the size of the microemulsion with increase in w0 (w0=[water]/[surfactant]) is evident from dynamic light scattering measurements. Consequently the mobility of the water molecules also increases. In comparison to pure water the retardation of solvation time in the RTIL containing ternary microemulsions is very less. The authors have also reported the solvation time of C-490 in neat [bmim][PF6]. The solvation time of C-490 in neat [bmim][PF6] is bimodal with time constants of 400ps and 1.10ns.

  5. Synthesis and Crystal Structure of [NiL2(H2O)2](ClO4)2L=MBPT=4-p-methylphenyl-3,5-bis-(pyridin-2-yl)-1,2,4-triazole

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Nickel (II) complex, [Ni(MBPT)2(H2O)2](ClO4)2 (MBPT=4-p-methylphenyl-3,5-bis-(pyridin-2-yl)-1,2,4-triazole), was synthesized and its crystal structure determined by X-ray diffraction methods.The complex adopts a distorted octahedral environment made up of two bidentate chelating MBPT ligands in the equatorial plane and two water molecules filling the axial positions.

  6. [Fe(mu-btzmp)(2)(btzmp)(2)](ClO4)(2) : a doubly-bridged 1D spin-transition bistetrazole-based polymer showing thermal hysteresis behaviour

    NARCIS (Netherlands)

    Quesada, Manuel; Kooijman, Huub; Gamez, Patrick; Costa, Jose Sanchez; van Koningsbruggen, Petra J.; Weinberger, Peter; Reissner, Michael; Spek, Anthony L.; Haasnoot, Jaap G.; Reedijk, Jan

    2007-01-01

    The reaction of btzmp (1,2-bis(tetrazol-1-yl)-2-methylpropane) with Fe(ClO4)(2) generates a 1D polymeric species, [Fe(mu-btzmp)(2)(btzmp)(2)](ClO4)(2), showing a steep spin transition (T-1/2 up arrow = 136 K and T-1/2 down arrow = 133 K) with a 3 K thermal hysteresis. The crystal structure at 100 an

  7. Dinuclear Cu(II) complexes of compartmental Schiff base ligands formed from unsymmetrical tripodal amines of varying arm lengths: Crystal structure of [Cu2L1](ClO4)2 and theoretical studies

    Science.gov (United States)

    Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Sayin, Koray

    2016-05-01

    Three new dinuclear copper complexes were synthesized via condensation reaction of three new unsymmetrical N-capped tripodal amines and 2,6-diformyl-4-methylphenol, in the presence of copper(II) perchlorate. The solid-state structure of the dinuclear complex, [Cu2L1](ClO4)2, has been determined by X-ray crystallography, showing that the CuII centers have distorted square-pyramidal geometry with N3O2 coordination. The copper (II) ions are bridged by phenolic and hydroxyalkyl groups when in both cases, deprotonation of the hydrogen atoms of the OH groups occurs. The distance between the copper atoms is 3.062 Å. This compound consists of the dication [Cu2L1]2+ and two ClO4- anions in which one of ClO4- groups has a week interaction with one of the Cu atoms. All complexes were characterized by a variety of physico-chemical techniques such as elemental analyses, IR, mass spectra, conductivity measurements and electronic spectral studies. Computational investigation of mentioned binuclear Cu(II) complexes was done by using M062X method with LANL2DZ basis set in vacuo.

  8. Volumetric and viscosity properties of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid in methanol%[Bmim]BF4离子液体在甲醇中的体积和黏度性质

    Institute of Scientific and Technical Information of China (English)

    李诗琴; 周贤丰; 许映杰

    2013-01-01

    在298.15 K和常压下,测定了1-丁基-3-甲基咪唑四氟硼酸([Bmim] BF4)离子液体+甲醇体系的密度和黏度.由密度计算了体系的表观摩尔体积,并采用Redlich-Mayer方程关联了体系的表观摩尔体积与组成的关系,得到了[Bmim]BF4在甲醇中的标准偏摩尔体积.由Jones-Dole方程对体系的黏度随组成的变化进行了拟合,获得了[Bmim] BF4在甲醇中的黏度B系数.结果表明:[Bmim] BF4+甲醇体系的表观摩尔体积和黏度均随[Bmim] BF4浓度的增加而增加,[Bmim] BF4在甲醇中的标准偏摩尔体积和黏度B系数分别为155.72×10-6m3/mol和0.282 9.%Densities and viscosities of l-butyl-3-methylimi-dazolium tetrafluoroborate ionic liquid ( [ Bmim ] BF4 ) with methanol were measured at 298. 15 K and atmospheric pressure. Apparent molar volumes, Vf of the above-mentioned mixture were determined from the experimental densities. Standard partial molar volume , Vo/f of [ Bmim] BF4 in methanol was estimated by the Redlich-Mayer equation. The achieved viscosities were used to calculate the viscosity B-coefficient of [ Bmim ] BF4 in methanol through Jones-Dole equation. The results indicate that the apparent molar volumes and viscosities increase with increasing of ionic liquid concentration. Standard partial molar volume and viscosity B-coefficient of [Bmim] BF4 in methanol is 155.72 ?10-6 m3 穖ol-1 and 0.282 9,respectively.

  9. Simultaneous determination of α-, β- and γ-asarone in Acorus tatarinowii by microemulsion electrokinetic chromatography with [BMIM]PF6 as oil phase.

    Science.gov (United States)

    Wang, Ying; Li, Feng; Yang, Feng-Qing; Zuo, Hua-Li; Xia, Zhi-Ning

    2012-11-15

    In the present study, a rapid and repeatable microemulsion electrokinetic chromatography (MEEKC) method was developed for the simultaneous determination of three isomers (α-, β- and γ-asarone) in Acorus tatarinowii by using ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF(6)) as oil phase. Experimental parameters including the microemulsion compositions (concentrations of surfactant, co-surfactant and oil phase), pH, concentration of borate buffer, capillary temperature and voltage were intensively investigated. Finally, the main compounds in the methanol extract of A. tatarinowii were well separated within 11 min using a running buffer composed of 40 mmol/L sodium dodecyl sulfonate (SDS), 2.0 mol/L n-propanol, 8 mmol/L [BMIM]PF(6) in 10 mmol/L borate buffer of pH 9.5. The developed method was applied to determine the contents of α-, β- and γ-asarone in A. tatarinowii from five different producing areas in China (Anhui, Hebei, Sichuan, Zhejiang and Chongqing). The results indicated that the contents of three asarones are quite different in the investigated A. tatarinowii samples. On the other hand, the MEEKC with ionic liquid as oil phase should be a promising method for the analysis of volatile components especially isomers in medicinal herbs. PMID:23158356

  10. Low-temperature thermodynamic investigation of the sulphur organic salts (TMTTF)2PF6 and (TMTTF)2Br (TMTTF = tetramethyltetrathiafulvalene): II. Dynamical aspects

    Science.gov (United States)

    Lasjaunias, J. C.; Monceau, P.; Staresinic, D.; Biljakovic, K.; Carcel, C.; Fabre, J. M.

    2002-09-01

    This contribution is in continuation of our preceding publication (Lasjaunias J C, Brison J P, Monceau P, Staresinic D, Biljakovic K, Carcel C and Fabre J M 2002 J. Phys.: Condens. Matter 14 837) in which we have considered general aspects of the low-temperature thermodynamical properties of the quasi-one-dimensional organic salts based on sulphur donors with different ground states: (TMTTF)2PF6 in the spin-Peierls state and (TMTTF)2Br (TMTTF = tetramethyltetrathiafulvalene) with commensurate spin modulation. In this part, part II, we present our results on the dynamical aspects related to the non-equilibrium phenomena measured below 1 K. The metastable states excited to slightly higher temperature (by only a few per cent of the starting T0) relax very slowly to the heat bath environment, depending on the duration of the heat pumping. We compare the features observed in the relaxation rates in these two sulphur compounds with those measured for the incommensurate spin-density-wave compound (TMTSF)2PF6. We discuss the possible nature of the long-living low-energy excitations lying at the origin of this complex dynamical behaviour, in relation to their ground states.

  11. Preparation and evaluation of modified composition for lyophilized kits of [Cu(MIBI4]BF4 for [99mTc] technetium labeling

    Directory of Open Access Journals (Sweden)

    Marisa de Jesus de C. Lima

    2005-10-01

    Full Text Available The [Cu(MIBI4]BF4 complex was synthesized and different formulations for lyophilized kits that could be cost-effectively used with different routines in nuclear medicine laboratories were investigated. In one preparation the kit components were kept similar to the Cardiolite® , except that the SnCl2.2H2O concentration was increased to 0.150 mg. In a second formulation, component concentrations were reduced to 1/5 of the original value and the SnCl2.2H2O concentration was adjusted to 0.04 mg. These products were labeled with maximum activities of 55.5 GBq and 8.14 GBq, respectively, and have shown an average radiochemical purity of 95 %. Biodistribution of the products was assessed by dissection in mice and in rabbits, and did not show any statistical difference when compared to Cardiolite®. In the synthesis of [Cu(MIBI4]BF4 a new procedure was introduced for the synthesis of N-(2-methyl-propenyl-formamide, with the use of microwave radiation as heat source. This modification reduced the reaction time to 25 seconds, while maintaining a yield of 68%.Neste trabalho são apresentados dados relativos a síntese do complexo [Cu(MIBI4]BF4 e à utilização do mesmo para produção de kit liofilizado para obtenção do radiofármaco [[99mTc](MIBI6]+. No processo de síntese foi utilizado radiação de microondas como fonte de aquecimento em uma etapa do processo, permitindo que a reação fosse executada em 25 segundos, obtendo rendimento de 68 %. Na preparação dos kits liofilizados, um deles denominado FULL, nos quais a quantidade dos componentes foi mantida igual ao produto comercial Cardiolite®, e outro denominado FRACTION, nos quais as quantidades foram reduzidas a 1/5 do total, foram adicionadas quantidades extras de SnCl2.2H2O. Deste modo, tornou-se possível marcar os kits liofilizados com atividades máximas de 55,5 GBq e 8,14 GBq, respectivamente. A biodistribuição dos produtos marcados, em camundongos e coelhos, não mostrou diferen

  12. Recent Advances in the Application of SelectfluorTMF-TEDA-BF4 as a Versatile Mediator or Catalyst in Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Stojan Stavber

    2011-07-01

    Full Text Available SelectfluorTM F-TEDA-BF4 (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo [2.2.2]octane bis(tetrafluoroborate is not only one of the most efficient and popular reagents for electrophilic fluorination, but as a strong oxidant is also a convenient mediator or catalyst of several “fluorine-free” functionalizations of organic compounds. Its applications as a mediator in transformations of oxidizable functional groups or gold-catalyzed C-C and C-heteroatom oxidative coupling reactions, a catalyst in formation of various heterocyclic rings, a reagent or catalyst of various functionalizations of electron-rich organic compounds (iodination, bromination, chlorination, nitration, thiocyanation, sulfenylation, alkylation, alkoxylation, a catalyst of one-pot-multi-component coupling reactions, a catalyst of regioselective ring opening of epoxides, a deprotection reagent for various protecting groups, and a mediator for stereoselective rearrangement processes of bicyclic compounds are reviewed and discussed.

  13. A facile route for the preparation of nanoparticles of the spin-crossover complex [Fe(Htrz)2(trz)](BF4) in xerogel transparent composite films.

    Science.gov (United States)

    Faulmann, Christophe; Chahine, Joe; Malfant, Isabelle; de Caro, Dominique; Cormary, Benoît; Valade, Lydie

    2011-03-21

    Films and monoliths containing the spin crossover complex [Fe(Htrz)(2)(trz)](BF(4)) (trz = 1,2,4-triazole) as nanoparticles have been obtained. The dispersion and consecutive inclusion of the Fe complex in a silica matrix prepared from tetramethoxysilane or tetraethoxysilane afford monoliths or films with a violet colour at room temperature, which turns white above 380 K. This change of colour is reversible. This thermochromic behaviour has been characterized by measuring the magnetic properties together with thermogravimetric studies and Raman spectroscopy, the result of which all demonstrate that both films and monoliths undergo a spin crossover. Microscopy studies confirm the occurrence of the Fe complex as nanoparticles, in both the monoliths and the films. The facile synthesis of these materials as nanoparticles in transparent films should open the possibility of the synthesis of high quality films. PMID:21290082

  14. Electrocatalytic oxidation and its electrochemical determination of quinine sulfate at SDBS - [bupy] PF_6 modified carbon paste electrode%硫酸奎宁在SDBS-[bupy]PF_6修饰碳糊电极上的电催化氧化及电分析方法

    Institute of Scientific and Technical Information of China (English)

    刘立红; 高作宁

    2010-01-01

    目的:研究了硫酸奎宁(quinine sulfate,QS)在十二烷基苯磺酸钠(sodium dodecyl benzenesulfonate,SDBS)自组装膜与离子液体N-丁基吡啶六氟磷酸盐([bupy]PF_6)复合修饰碳糊电极(SDBS-[bupy]PF_6/CPE)上的电化学行为和电化学动力学性质,建立了QS电化学定量测定方法.方法:循环伏安法(CV),计时电流法(CA),计时库仑法(CC),方波伏安法(SWV)以及电化学交流阻抗法(EIS).结果:在SDBS-[bupy]PF_6/CPE上,QS发生了受扩散控制的不可逆电化学氧化过程.测得QS在SDBS-[bupy]PF_6/CPE上的电极反应过程动力学参数.用SWV法测得QS氧化峰电流与其浓度在5.0 ×10~(-6)~1.0×10~(-4)mol·L~(-1)和1.0×10~(-4)~1.0×10~(-3)mol·L~(-1)呈线性关系,检测限为3.5×10~(-7)mol·L~(-1).采用本方法对市售二盐酸奎宁注射液进行了电化学定量测定,RSD在1.3%~3.4%之间,加标回收率在98.0%~103%之间.结论:SDBS-[bupy]PF_6/CPE对QS电化学氧化具有良好的催化作用,该方法可用于市售奎宁类药物含量的电化学定量测定,方法操作简单,测定结果令人满意.

  15. Monodisperse Ru Nanoparticles in [Bmim]BF4:Preparation and Application in Benzene Selective Hydrogenation%离子液体[Bmim]BF4中单分散Ru纳米粒子的制备及选择加氢性能

    Institute of Scientific and Technical Information of China (English)

    魏珺芳; 王延吉; 励娟; 薛伟

    2011-01-01

    The monodisperse Ru nanoparticles were prepared by chemical reduction method in 1-butyl-3-methyl limidizaolium tetrafluoroborate ([BMim]BF4). The prepared Ru nanoparticles were characterized by XRD as hexagonal close packed structure and no diffraction peak from oxidation products. TEM analysis of these nanoparticles shows that the monodisperse Ru nanoparticles prepared by positive dripping method disperse in the ionic liquids with diameter less than 5 nm. The Ru nanoparticles prepared by reverse dripping method agglomerate with diameter more than 10 nm. FTIR results indicate that a physically absorbed layer of ionic liquid is evident on the surface of Ru nanoparticles. TG results indicate that the ionic liquid serves not only as a protective agent or stabilizing agent to inhibit the aggregation of Ru nanoparticles, but also a modification agent adsorbed on the Ru nanoparticles. Results of benzene selective hydrogenation show that benzene conversion is relatively high in the reaction system with water, however the selectivity of cyclohexene is low, only 14.5% at 27.3% benzene conversion in the same system.%采用化学还原法在离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMim]BF4)中制备了单分散纳米金属Ru粒子.采用X射线衍射(XRD)、透射电镜(TEM)、傅里叶红外光谱(FTTR)及热重(TG)对所制备样品的形貌和结构进行了表征.XRD表征结果显示:在[BMim]BF4中制备的Ru具有六方紧密堆积结构,无氧化物峰出现;TEM结果显示:采用正滴法制备的Ru纳米粒子为球形颗粒,呈现良好的单分散状态,粒径分布窄,为2~5 nm,而采用反滴法制备的Ru纳米粒子则发生了严重的团聚,团聚体粒径大于10 nm;FTIR表征表明:Ru纳米粒子表面存在[BMjm]BF4液体层,分析二者之间存在较强的物理吸附作用,[BMim]BF4在Ru纳米粒子的制备中起到了修饰剂和保护剂的双重作用,这一推论通过TG分析得到了进一步验证.将分散于[BMim]BF4的Ru纳

  16. Preparation and characterization of electropolymerized poly(3,4-ethylenedioxythiophene) thin films with different dopant anions

    Science.gov (United States)

    Deguchi, Toshiaki; Tomeoku, Hiroya; Takashiri, Masayuki

    2016-06-01

    We investigated the structural and thermoelectric properties poly(3,4-ethylenedioxythiophene) (PEDOT) films with several dopants (counter ions, ClO4, PF6, and BF4), synthesised by electropolymerization. We first performed cyclic voltammetry analysis to determine the optimum synthesis conditions of the PEDOT thin films. We found that the surface morphology of the PEDOT thin films was dependent on the type of the dopant. The PF6-doped PEDOT (PEDOT:PF6) thin films showed a dense structure, and the PEDOT:ClO4 thin films showed a highly porous microstructure. Fourier transform infrared (FT-IR) spectroscopy showed that all the PEDOT thin films showed similar chemical structures and the p-type state. Regarding their thermoelectric properties, the electrical conductivity of the all the doped PEDOT thin films increased as the dopant concentration increased, with the PEDOT:PF6 thin films showing the highest value. On the other hand, the Seebeck coefficient of the PEDOT thin films with all the dopants decreased as the dopant concentration increased, with the PEDOT:BF4 thin films achieving the highest value. As a result, the PEDOT:BF4 thin films exhibited the highest power factor of 0.75 µW/(m·K2) at a dopant concentration of 1.0 M. We think that the PEDOT microstructure produced using the different types of dopant may affect the thermoelectric properties.

  17. Effects of Propylene Carbonate Content in CsPF6-Containing Electrolytes on the Enhanced Performances of Graphite Electrode for Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Cao, Ruiguo; Xiang, Hongfa; Engelhard, Mark H.; Polzin, Bryant; Wang, Chong M.; Zhang, Jiguang; Xu, Wu

    2016-02-10

    Cesium salt has been demonstrated as an efficient electrolyte additive in suppressing the lithium (Li) dendrite formation and directing the formation of an ultrathin and stable solid electrolyte interphase (SEI) even in propylene carbonate (PC)-ethylene carbonate (EC)-based electrolytes. Here, we further investigate the effect of PC content in the presence of CsPF6 additive (0.05 M) on the performances of graphite electrode in Li||graphite half cells and in graphite||LiNi0.80Co0.15Al0.05O2 (NCA) full cells. It is found that the performance of graphite electrode is also affected by PC content even though CsPF6 additive is present in the electrolytes. An optimal PC content of 20% by weight in the solvent mixtures is identified. The enhanced electrochemical performance of graphite electrode is attributed to the synergistic effects of the Cs+ additive and the PC solvent. The formation of a robust, ultrathin and compact SEI layer containing lithium-enriched species on the graphite electrode, directed by Cs+, effectively suppresses the PC co-intercalation and thus prevents the graphite exfoliation. This SEI layer is only permeable for de-solvated Li+ ions and allows fast Li+ ion transport through it, which therefore largely alleviates the Li dendrite formation on graphite electrode during lithiation even at high current densities. The presence of low-melting-point PC solvent also enables the sustainable operation of the graphite||NCA full cells under a wide spectrum of temperatures. The fundamental findings of this work shed light on the importance of manipulating/maintaining the electrode/electrolyte interphasial stability in a variety of energy storage devices.

  18. Effects of ionic liquid [bmim][PF6] on absorption spectra and reaction kinetics of the duroquinone triplet state in acetonitrile.

    Science.gov (United States)

    Zhu, Guanglai; Wu, Guozhong; Sha, Maolin; Long, Dewu; Yao, Side

    2008-04-10

    The transient absorption spectra and photoinduced electron-transfer process of duroquinone (DQ) in mixed binary solutions of ionic liquid (IL) [bmim][PF6] and acetonitrile (MeCN) have been investigated by laser photolysis at an excitation wavelength of 355 nm. A spectral blue shift of 3DQ* was observed in the IL/MeCN mixtures compared to MeCN. At lower VIL(volume fraction of IL), the interaction between DQ and the solvent is dominant, and the decay rate constant (kobs) of 3DQ* increases steadily with the increasing of VIL; to the contrary, at higher VIL, the network structures due to the hydrogen bond and viscosity are dominant, and the decay rate constant decreases obviously with increasing VIL. A critical point (turnover) was observed at VIL = approximately 0.30. The dependence of the observed growth rate (kgr) of the photoinduced electron-transfer (PET) products on VIL is complex and shows a special change; kgr first decreases with increasing VIL, then increases, and finally decreases slowly with further increasing of VIL. It is speculated that the PET process in the mixture can be affected by factors including the local structure and the reorganization energy of the solvent and salt and cage effects. The change of local structure of [bmim][PF6]/MeCN is supported by following the steady-state fluorescence behavior of the mixture, in combination with the molecular dynamics simulation of the thermodynamic property. The results revealed that the degree of self-aggregation of monomeric cations (bmim+) to associated forms increases with increasing VIL. This is in good agreement with the laser photolysis results for the same solutions. PMID:18331005

  19. [C4mim][BF4]与乙醇胺和N,N-二甲基乙醇胺混合体系的密度、黏度和电导率%Densities,Viscosities and Electrical Conductivities of [C4mim][BF4],MEA and DMEA

    Institute of Scientific and Technical Information of China (English)

    耿彦芳; 刘鑫; 虞大红; 彭昌军; 刘洪来

    2009-01-01

    分别采用比重瓶、乌氏黏度计和电导率仪测定了1-丁基-3-甲基咪唑四氟硼酸盐([C4mim][BF4])+乙醇胺(MEA)和[C4mim][BF4]+N,N-二甲基乙醇胺(DMEA)两种二元混合物在283.15~323.15 K时的密度、黏度和电导率.用Redlich-Kister方程关联并计算了混合体系的过量摩尔体积和黏度偏差.通过电导率的实验结果计算得到了混合体系的摩尔电导率,证明有机溶剂摩尔含量对混合体系摩尔电导率的贡献符合Walden规则.

  20. Two-phase Beckmann Rearrangement of Cyclohexanone Oxime for Preparing ε-Caprolactam in [bmim] [BF4] Ionic Liquids Using PCl3 as Catalyst%[bmim][BF4]离子液体中PCl3催化的液相贝克曼重排

    Institute of Scientific and Technical Information of China (English)

    张伟; 吴巍; 张树忠; 闵恩泽

    2004-01-01

    在1-丁基-3-甲基咪唑四氟硼酸盐([bmim][BF4])与甲苯组成的两相体系中,以三氯化磷(PCl3)为催化剂,实现了由环己酮肟制备己内酰胺的液相贝克曼重排反应,两相体系有利于反应控制和体系取热.研究了环己酮肟用量、PCl3用量、反应时间和反应温度对重排效果的影响.优化反应条件为:2 ml[bmim][BF4],5 ml甲苯,0.3 ml PCl3,5 ml 2 mol/L环己酮肟-甲苯溶液,90℃,反应时间10~30 min.此时,环己酮肟转化率达98.96%,生成己内酰胺的选择性达87.30%,PCl3催化转化数达2.88.生成的大部分己内酰胺在离子液体相.

  1. Ru( dpp)3(ClO4)2掺杂的聚丙烯腈纳米颗粒的制备及其在比率荧光pH检测中的应用%Synthesis of Ru (dpp) 3 ( ClO4 ) 2 doped polyacrylonitrile nanoparticles and its applications in ratiometric pH sensing

    Institute of Scientific and Technical Information of China (English)

    叶廷秀; 王旭东; 陈小霞; 张英雪; 屈艳勤; 陈曦

    2011-01-01

    In this paper Ru (dpp ) 3 ( C104) 2 doped polyacrylonitrile nanoparticles ( Ru - PAN ) were prepared using emulsion polymerization method. Morphology characterizations of the nanoparticles were performed using scanning electron microscope, the particle diameter was about 135 ± 15 nm. The in terference of the oxygen, coexisting ions, pH and photo - stability were investigated. A new ratiomet ric fluorescence pH sensing system was established via fluorescein isothiocyanate (FITC) as pH - sen sitive dye and Ru - PAN as a reference.%采用乳液聚合法制备了掺杂有4,7-二苯基-1,10-邻菲咯啉钌(Ru( dpp)3( ClO4)2)的聚丙烯腈纳米颗粒(Ru- PAN).经扫描电子显微镜(SEM)表征,制备的Ru - PAN的尺寸为135±15 nm,呈规则球型,尺寸分布均匀且在水中的分散性较好.实验考察了氧气、共存离子和pH值对其荧光性质的影响以及其荧光稳定性.以异硫氰根荧光素(FITC)为pH荧光指示剂、Ru - PAN为参比信号,初步建立了一种比率荧光pH检测的方法.

  2. 高压下NH4ClO4结构、电子及弹性性质的第一性原理研究%First principles investigations of structural, electronic and elastic prop erties of ammonium p erchlorate under high pressures

    Institute of Scientific and Technical Information of China (English)

    刘博; 王煊军; 卜晓宇

    2016-01-01

    Ammonium perchlorate (NH4ClO4) is a highly energetic oxidizer widely used in solid propellants and explosives. Under extreme pressure conditions, significant changes are observed in the structures and properties of NH4ClO4. How-ever, many studies of structural transformations of NH4 ClO4 under high pressures have not formed a more consistent conclusion. In this study, the structural, electronic, and elastic properties of NH4ClO4 are investigated by first-principles calculations based on the density functional theory with dispersion correction (DFT-D) method in a range of 0–15 GPa. The unit cell volume and lattice parameters are optimized by GGA/PBE-TS, which leads to good agreement with the experimental structure parameters at 0 GPa, suggesting the reliability of the present calculation method. The calculated P-V data are fitted to the third-order Birch-Murnaghan equation of state, and the result provides better agreement with experimental result than other calculations for the unit cell with a volume V0 and bulk moduli B0 and B′. The comprehensive analyses of the lattice parameters, bond lengths, and hydrogen bonds under high pressure indicate that three structural transformations occur in NH4ClO4 at 1 GPa, 4 GPa, and 9 GPa. With increasing pressure, hydrogen bonding interaction gradually increases, and intra- and intermolecular hydrogen bonds are present in crystals. Results obtained from the band structures and state densities under high pressure indicate that NH4ClO4 exhibits good insu-lating properties. Valence band shifts towards low energy, conduction band shifts towards high energy, and electronic localization is enhanced. The charge density differences and Mulliken charge populations at different pressures reveal that the covalent interaction between the N—H and Cl—O bonds increases, and the ionicity of crystal decreases. The band gaps in different structural transition regions exhibit different linear increase trends with increasing pressure. The calculated elastic constants of NH4ClO4 satisfy elastic stability criteria of orthorhombic systems at pressures ranging from 0 GPa to 15 GPa, indicating that NH4ClO4 is mechanically stable. The bulk modulus, shear modulus, and Young’s modulus are estimated by the Voigt-Reuss-Hill approach. The Cauchy pressures and B/G values indicate that NH4ClO4 exhibits ductility, attributed to the fact that NH4ClO4 is an ionic crystal, and ionic bonds are non-directional bonds;hence, NH4ClO4 is ductile and can be easily bended or reshaped. The results indicate that the ductility properties of NH4ClO4 increase with increasing pressure. All calculated properties are in excellent agreement with the available ex-perimental results. These results will not only help to understand the structural transformations of NH4ClO4 under high pressures but also provide an important theoretical reference for the safe application of NH4ClO4 in solid propellants and explosives.

  3. Spectroscopy, thermal and structural studies of new Zn II coordination polymer, [Zn 3(μ-bpa) 4.5(AcO) 3](ClO 4) 3·4.26H 2O

    Science.gov (United States)

    Amiri, Maryam Ghoreishi; Morsali, Ali; Hunter, Allen D.; Zeller, Matthias

    2007-11-01

    Three Zn II coordination polymers with acetate and perchlorate anions, [Zn 3(μ-bpa) 4.5(AcO) 3](ClO 4) 3·4.26H 2O ( 1), [Zn 2(μ-bpe) 3(AcO) 2](ClO 4) 2 ( 2) and [Zn 2(bpe)(AcO) 4] ( 3), bpa = 1,2-bis(4-pyridyl)ethane and bpe = 1,2-bis(4-pyridyl)ethene, have been synthesized and characterized by elemental analysis, IR, 1H NMR, and 13C NMR spectroscopies, and the structure of compound 1 was determined by single-crystal X-ray diffraction. The thermal stabilities of compounds 1- 3 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The structural studies of compound 1 show that the structure may be considered as a three-dimensional coordination polymer of zinc(II) with large voids filled with disordered water molecules. The stability of the porous networks after removal of the guest water molecules is confirmed by X-ray powder diffraction.

  4. Lanthanide Complex[Xd(dpdo)4(H2O)3][ClO4]3·4.5H2O·dpdo Containing Framework Based on 4,4′—Dipyradine—Dioxide

    Institute of Scientific and Technical Information of China (English)

    马宝清; 孙豪岭; 等

    2002-01-01

    A novel lanthanide coordination polymer formulated as [Nd(dpdo)4(H2O)3][ClO4]4·4.5H2O·dpdo1(dpdo=4,4′-dipyrazine-dioxide)was synthesized and structurally characterized.The Nd3+ions are bridged by dpdo ligands in a cis-mode to form a zigzag chain along[001]direction.Meanwhile,each Nd3+ion is coordinated with three terminal dpdo molecules.One of them is overlapped with the bridging one throughπ-πstackings,and the orher wto are bound to the opposite directions of the bridging ones,producing a ribbon-like motif with rectangular cavity,These adjacent ribbons are connected thorough inter-molecularπ-πstackings to give parquet-like architecture with a large rectangular channel(1.108nm×1.660nm)in which the crystal lattice water molecules and ClO-4anions are included.Thermalanalysis shows that the solvate dpdo and water molecules can be removed at lower temperature,while coordinated dpdo molecules are lost simultaneously at higher temperature.

  5. Synthesis and Crystal Structure of{[Mn(H2O)4(3, 3′-azpy)](3, 3′-azpy)3(PF6)2}n

    Institute of Scientific and Technical Information of China (English)

    李宝龙; 曹正白; 王寿武; 徐正; 郁开北

    2002-01-01

    The complex {[Mn(H2O)4(3, 3?-azpy)](3, 3?-azpy)3(PF6)2}n (3, 3?-azpy = 3, 3?- azobispyridine) has been synthesized and characterized. The crystal (C40H40F12MnN16O4P2, Mr = 1153.76) belongs to the triclinic system, space group P ī with the following crystallographic parameters: a = 10.761(2), b = 11.040(2), c = 23.365(4) ?, ( = 85.52(1), ( = 82.69(1), ( = 70.44(1)°, V = 2592.5(8) ?3, Dc = 1.478 g/cm3, ((MoK() = 4.16 cm-1, F(000) = 1174, Z = 2, final R = 0.0493 and wR = 0.1158 for the observed reflections (I > 2.00((I)). The X-ray analysis revealed that manganese(Ⅱ) cation coordination environment is a distorted octahedral geometry, and the Mn2+ cation is coordinated by four oxygen atoms of water in the equatorial plane, while the two nitrogen atoms of 3, 3?-azpy occupy the axial positions. The complex forms a one-dimensional chain structure via 3, 3?-azpy bridging ligand.

  6. Sodium-ion-conducting polymer nanocomposite electrolyte of TiO2/PEO/PAN complexed with NaPF6

    Science.gov (United States)

    Bhatt, Chandni; Swaroop, Ram; Sharma, Parul Kumar; Sharma, A. L.

    2016-05-01

    A free standing transparent film of solid state polymer electrolyte based on PEO/PAN+NaPF6 with different compositions of nano sized TiO2 in weight percent (x = 0, 1, 2, 5, 10, 15, 20) is synthesized by using standard solution cast technique. The homogeneous surface of above polymer composition is examined by FESEM. The microscopic interaction among polymer, salt and nanoceramic filler has been analyzed by Fourier Transformed Infra-Red (FTIR) spectroscopy. The reduction of ion pair formation in polymeric separator is clearly observed on addition of nanofiller in the polymer salt complex film. Electrical conductivity has been recorded of the prepared polymeric separator which is of the order of ˜10-4 Scm-1 after addition of nanofiller (15% wt/wt) which support the FTIR results. Electrochemical potential window has been observed of the order of ˜6V by the cyclic voltammetry results. The observed data of the prepared separator are at par with the desirable value for device applications

  7. Complex dissociation synthesis of batterty-grade LiPF6%络合解离法制备电池级六氟磷酸锂新工艺研究

    Institute of Scientific and Technical Information of China (English)

    郑典模; 郭红祥; 徐文赫; 陈秋霞

    2016-01-01

    A complex dissociation method was used to prepare battery-grade LiPF6 using pyridine、fluorophosphoric acid and lithium hydrate as the raw materials. Fluorophosphoric acid reacts with pyridine to form intermediate C5 H5 NHPF6 ,and then this intermedi-ate reacts with lithium hydrate to produce LiC5H5NPF6. LiC5H5NPF6 can be dissociated into LiPF6 in homemade reaction vessel. The results of XRD、IR、HNMR、AAS show that the product of the experiment was LiPF6 ,and its purity was more than 99. 9%.%本文以吡啶、六氟磷酸和氢氧化锂为原料,采用络合解离法制备电池级LiPF6。首先采用吡啶与六氟磷酸反应生成吡啶六氟磷酸,然后通过吡啶六氟磷酸与氢氧化锂锂交换得到吡啶六氟磷酸锂,吡啶六氟磷酸锂常温负压分解得到LiPF6。 XRD、红外光谱、核磁共振氢谱、原子吸收光谱的分析结果表明得到的六氟磷酸锂纯度大于99.9%。

  8. Deposition, Accumulation, and Alteration of Cl(-), NO3(-), ClO4(-) and ClO3(-) Salts in a Hyper-Arid Polar Environment: Mass Balance and Isotopic Constraints

    Science.gov (United States)

    Jackson, Andrew; Davila, Alfonso F.; Boehlke, J. K.; Sturchio, Neil C.; Sevanthi, Ritesh; Estrada, Nubia; Brundrette, Megan; Lacell, Denis; McKay, Christopher P.; Poghosyan, Armen; Pollard, Wayne; Zacny, Kris

    2016-01-01

    The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in MDV permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl(-), NO3(-, ClO4(-)and ClO3(-)in dry and ice-cemented soil/sediments, snow and glacier ice, and also characterized Cl(-) and NO3(-) isotopically. The data are not consistent with salt deposition in a sublimation till, nor with nuclear weapon testing fall-out, and instead point to a dominantly stratospheric source and to varying degrees of post depositional transformation depending on the substrate, from minimal alteration in bare soils to significant alteration (photodegradation and/or volatilization) in snow and glacier ice. Ionic abundances in the dry permafrost layer indicate limited vertical transport under the current climate conditions, likely due to percolation of snowmelt. Subtle changes in ClO4(-)/NO3(-) ratios and NO3(-) isotopic composition with depth and location may reflect both transport related fractionation and depositional history. Low molar ratios of ClO3(-)/ClO4(-) in surface soils compared to deposition and other arid systems suggest significant post depositional loss of ClO3(-), possibly due to reduction by iron minerals, which may have important implications for oxy-chlorine species on Mars. Salt accumulation varies with distance along the valley and apparent accumulation times based on multiple methods range from approximately 10 to 30 kyr near the glacier to 70-200 kyr near the valley mouth. The relatively young age of the salts and relatively low and homogeneous anion concentrations in the ice-cemented sediments point to either a mechanism of recent salt removal, or to relatively modern permafrost soils (less than 1 million years). Together, our results show that near surface salts in University Valley serve as an end-member of stratospheric sources not subject to biological processes or extensive remobilization.

  9. Deposition, accumulation, and alteration of Cl-, NO3-, ClO4- and ClO3- salts in a hyper-arid polar environment: Mass balance and isotopic constraints

    Science.gov (United States)

    Jackson, Andrew; Davila, Alfonso F.; Böhlke, John Karl; Sturchio, Neil C.; Sevanthi, Ritesh; Estrada, Nubia; Brundrett, Maeghan; Lacelle, Denis; McKay, Christopher P.; Poghosyan, Armen; Pollard, Wayne; Zacny, Kris

    2016-06-01

    The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in MDV permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl-, NO3-, ClO4- and ClO3- in dry and ice-cemented soil/sediments, snow and glacier ice, and also characterized Cl- and NO3- isotopically. The data are not consistent with salt deposition in a sublimation till, nor with nuclear weapon testing fall-out, and instead point to a dominantly stratospheric source and to varying degrees of post depositional transformation depending on the substrate, from minimal alteration in bare soils to significant alteration (photodegradation and/or volatilization) in snow and glacier ice. Ionic abundances in the dry permafrost layer indicate limited vertical transport under the current climate conditions, likely due to percolation of snowmelt. Subtle changes in ClO4-/NO3- ratios and NO3- isotopic composition with depth and location may reflect both transport related fractionation and depositional history. Low molar ratios of ClO3-/ClO4- in surface soils compared to deposition and other arid systems suggest significant post depositional loss of ClO3-, possibly due to reduction by iron minerals, which may have important implications for oxy-chlorine species on Mars. Salt accumulation varies with distance along the valley and apparent accumulation times based on multiple methods range from ∼10 to 30 kyr near the glacier to 70-200 kyr near the valley mouth. The relatively young age of the salts and relatively low and homogeneous anion concentrations in the ice-cemented sediments point to either a mechanism of recent salt removal, or to relatively modern permafrost soils (end-member of stratospheric sources not subject to biological processes or extensive remobilization.

  10. Electrochemical behaviors of Fenbendazole at graphene and[ Bupy] PF6 modified carbon paste electrode and its electrochemical determination%芬苯达唑在石墨烯与[ Bupy ] PF6复合修饰碳糊电极上的电化学性质及电分析方法研究

    Institute of Scientific and Technical Information of China (English)

    田碧桃; 李金来; 王维; 犹卫; 彭娟; 高作宁

    2015-01-01

    本文研究了芬苯达唑( Fenbendazole,FBZ)在石墨烯( RGO)与离子液体( N-丁基吡啶六氟磷酸盐)复合修饰碳糊电极上的电催化氧化及电化学动力学性质。同时用CC法(计时库仑法)、计时电流法( CA)测定FBZ在RGO-[ Bupy] PF6/CPE上的电极反应动力学参数,并用方波伏安法( SWV)测定FBZ氧化峰电流( Ip )与其浓度c在4.0×10-8~1.0×10-5mol·L-1范围内呈良好线性关系,线性回归方程为Ip(μA)=1.471+5220.78c (10-3mol·L-1),R=0.9995,检测限(S/N=3)为1.4×10-9mol·L-1,在此基础上用SWV法对FBZ片剂中FBZ含量进行了电化学定量测定,RSD在0.2%~0.9%之间,回收率在99.0%~101.4%之间。%Objective:Electrocatalytic oxidation and its electrochemical kinetics of fenbendazole( FBZ) were investigated by Cyclic voltammetry(CV)method at carbon paste electrode(CPE)which modified by graphene(RGO)and [Bupy]PF6. The experiment re-sults indicated that FBZ electrochemical behaviors exhibits an irreversible electrochemical oxidation progress at RGO-[ Bupy] PF6/CPE,The electrochemical kinetic parameters were determined by chronocoulometry ( CC) and chronoamperometry ( CA) at RGO-[ Bupy] PF6/CPE. The oxidation peak current of FBZ versus its concentration had a good linear relationship in the concentration range of 4. 0 × 10-8 ~1. 0 × 10-5 mol·L-1and the detection limit(S/N=3)was 1. 4 × 10-9mol·L-1 by square wave voltammetric (SWV)method. The equation of linear regression was Ip(μA)=1. 471+5220. 78c(10-3mol·L-1),R=0. 9995,Also the proposed method have been applied in electrochemical quantitative determination of FBZ content in commercial tablet samples,with their rel-ative standard deviations of 0. 2% ~0. 9%and recoveries of 99. 0% ~101. 4%.

  11. Reactions of [Cu(X)(BPEP-Ph)] (X = PF6, SbF6) with silyl compounds. Cooperative bond activation involving non-coordinating anions.

    Science.gov (United States)

    Nakajima, Yumiko; Tsuchimoto, Takahiro; Chang, Yung-Hung; Takeuchi, Katsuhiko; Ozawa, Fumiyuki

    2016-02-01

    Bond activation of silyl compounds, assisted by the cooperative action of non-coordinating anions, is achieved using Cu(I) complexes coordinated with a PNP-pincer type phosphaalkene ligand, [Cu(X)(BPEP-Ph)] (X = PF6 (1a), SbF6 (1b); BPEP-Ph = 2,6-bis[1-phenyl-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyl]pyridine). Complexes 1a and 1b react with Me3SiCN to form Me3SiF and Cu(i) cyanide complexes of the formula [Cu(CN-EF5)(BPEP-Ph)] (E = P (2a), Sb (2b)), in which the CN ligand is associated with the EF5 group arising from EF6(-). Formation of the intermediary isonitrile complex [Cu(CNSiMe3)(BPEP-Ph)](+)SbF6(-) (3b) is confirmed by its isolation. Thus, a two-step reaction process involving coordination of Me3SiCN, followed by nucleophilic attack of SbF6(-) on the silicon atom of 3b is established for the conversion of 1b to 2b. Complex 1b cleaves the H-Si bond of PhMe2SiH as well. The isolation and structural identification of [Cu(BPEP-Ph)](+)BAr(F)4(-) (1c) (BAr(F)4 = B{3,5-(CF3)2C6H3}4) as a rare example of a T-shaped, three-coordinated Cu(i) complex is reported. PMID:26455594

  12. Highly efficient extraction and oxidative desulfurization system using Na7H2LaW10O36⋅32 H2O in [bmim]BF4 at room temperature.

    Science.gov (United States)

    Xu, Junhua; Zhao, Shen; Chen, Wei; Wang, Miao; Song, Yu-Fei

    2012-04-10

    Highly efficient, deep desulfurization of model oil containing dibenzothiophene (DBT), benzothiophene (BT), or 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved under mild conditions by using an extraction and catalytic oxidative desulfurization system (ECODS) in which a lanthanide-containing polyoxometalate Na(7)H(2)LnW(10)O(36)⋅32 H(2)O (LnW(10); Ln = Eu, La) acts as catalyst, [bmim]BF(4) (bmim = 1-butyl-3-methylimidazolium) as extractant, and H(2)O(2) as oxidant. Sulfur removal follows the order DBT>4,6-DMDBT>BT at 30 °C. DBT can be completely oxidized to the corresponding sulfone in 25 min under mild conditions, and the LaW(10)/[bmim]BF(4) system could be recycled for ten times with only slight decrease in activity. Thus, LaW(10) in [bmim]BF(4) is one of the most efficient systems for desulfurization using ionic liquids as extractant reported so far. PMID:22374858

  13. Synthesis of the compound tetrakis (2- methoxy isobutyl isonitrile) copper (I) tetrafluoroborate -(Cu[MIBI]4BF4): substance used in the production of the radiopharmaceutical sestamibi 99m Tc

    International Nuclear Information System (INIS)

    The radiopharmaceutical SESTAMIBI-99mTc presents interest and application in the clinical routine in Nuclear Medicine, especially for evaluation of the myocardium function and in the diagnosis of some tumors types, and the Center of Radiopharmacy of the IPEN has interest in the development of this radiopharmaceutical for attendance of the nuclear medicine class necessities. In this work it was demonstrated the synthesis and characterization of the active compound tetrakis (2- methoxy isobutyl isonitrile) copper (I) tetrafluoroborate - Cu[MIBI]4BF4- to be used in the preparation of lyophilized reagents for labeling with technetium-99m as well as labeling studies and biological distribution. The synthesis of the reagent Cu[MIBI]4BF4 was carried out in accordance with previously described procedures, in 5 steps and the compounds were characterized for infra-red, magnetic nuclear resonance, melting point and thin layer chromatography. The characterization of the chelate of MIBI -Cu[MIBI]4BF4 - was carried out using high performance liquid chromatography, compared with a standard sample of the product and presented similar results, as described in literature. The lyophilized reagent was prepared and labeled with technetium-99m, showing high radiochemical purity, higher than 97%, with high stability. Biological distribution in different animals showed good uptake in the heart, in time compatible with the acquisition of scintigraphy images, demonstrating the applicability of the reagent synthesized in the attainment of cardiac scintigraphy images. (author)

  14. 离子液体[C4mim ][PF6]萃取-石墨炉原子吸收法检测食品中的痕量铅%The Determination of Lead by Graphit Furnace Atomic Absorption Spectrometry Couple with Ionic Liquid [C4 min][PF6 ] Extraction in Food

    Institute of Scientific and Technical Information of China (English)

    王乃丽; 王金梅

    2013-01-01

    离子液体因其具有不挥发,粘度大等特性,已被广泛代替有机溶剂用于液液萃取。建立了以二乙基二硫代氨基甲酸钠(DDTC)为螯合剂、离子液体1-丁基-3-甲基咪唑六氟磷酸盐([C4 mim][PF6])为萃取剂、稀硝酸为反萃取溶剂的萃取体系,并对所建立的萃取体系的相关影响因素进行了优化,包括:体系pH、螯合剂DDTC的用量、反萃取溶剂的选择等。同时对该离子液体是否可循环利用以及该体系的抗干扰能力进行了评价。此外,将所建立的离子液体萃取-稀硝酸反萃取体系结合石墨炉原子吸收分光光度法应用于大米,茶,鱼,小麦,蛤以及油菜中的痕量铅的检测。%The ionic liquid has replaced the organic solvent as the extraction solvent for it's including non-volatile and high viscosity .DDTC was selected as chelating agent ,[C4 mim][PF6 ] as the extraction agent and HNO3 as back-extraction agent .The optimized experimental condition was :pH of the extraction , the concentration of DDTC ,the back-extraction solvent .Meanwhile ,recyclable of the ionic liquid and an-ti-interference were also discussed .Finally ,this method was successfully applied in the determination of the trace Pb existed in the rice ,tea ,fish ,wheat ,clam and rape .

  15. Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide ((38)ArO4) from ((38)ClO4(-)) and the evolution of chemical bonding over the nuclear transmutation reaction path.

    Science.gov (United States)

    Timm, Matthew J; Matta, Chérif F

    2014-12-01

    Argon tetroxide (ArO4) is the last member of the N=50 e(-) isoelectronic and isosteric series of ions: SiO4(4-), PO4(3-), SO4(2-), and ClO4(-). A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ~298kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295-8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52-53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4(-)) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope (38)Cl to the stable rare argon isotope (38)Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar-O bond. As a result, a primary retention yield of ~1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6-311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar-O bond dissociation product ArO3+O((3)P) from which the predicted barrier to dissociation is ca. 22kcal/mol and the exothermic reaction energy is ca. 28kcal/mol [(U)MP2/6-311+G(d)].

  16. Deposition, accumulation, and alteration of Cl−, NO3−, ClO4− and ClO3− salts in a hyper-arid polar environment: Mass balance and isotopic constraints

    Science.gov (United States)

    Jackson, Andrew; Davila, Alfonso F.; Böhlke, John Karl; Sturchio, Neil C.; Sevanthi, Ritesh; Estrada, Nubia; Brundrett, Maeghan; Lacelle, Denis; McKay, Christopher P.; Poghosyan, Armen; Pollard, Wayne; Zacny, Kris

    2016-01-01

    The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in MDV permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl−, NO3−, ClO4− and ClO3− in dry and ice-cemented soil/sediments, snow and glacier ice, and also characterized Cl− and NO3−isotopically. The data are not consistent with salt deposition in a sublimation till, nor with nuclear weapon testing fall-out, and instead point to a dominantly stratospheric source and to varying degrees of post depositional transformation depending on the substrate, from minimal alteration in bare soils to significant alteration (photodegradation and/or volatilization) in snow and glacier ice. Ionic abundances in the dry permafrost layer indicate limited vertical transport under the current climate conditions, likely due to percolation of snowmelt. Subtle changes in ClO4−/NO3− ratios and NO3− isotopic composition with depth and location may reflect both transport related fractionation and depositional history. Low molar ratios of ClO3−/ClO4− in surface soils compared to deposition and other arid systems suggest significant post depositional loss of ClO3−, possibly due to reduction by iron minerals, which may have important implications for oxy-chlorine species on Mars. Salt accumulation varies with distance along the valley and apparent accumulation times based on multiple methods range from ∼10 to 30 kyr near the glacier to 70–200 kyr near the valley mouth. The relatively young age of the salts and relatively low and homogeneous anion concentrations in the ice-cemented sediments point to either a mechanism of recent salt removal, or to relatively modern permafrost soils (<1 million years). Together, our results show that near surface salts in University Valley serve as an end-member of stratospheric sources not subject to biological processes or extensive remobilization.

  17. Heat capacity and thermodynamical properties of the crystal of [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE=Nd,Eu,Dy)

    Institute of Scientific and Technical Information of China (English)

    WU XinMin; LI Wei; TAN ZhiCheng; QU SongSheng

    2009-01-01

    Thermodynamical data of rare earth complexes with amino acid are important for engineering chemistry and fundamental chemistry.However,they have rarely been reported.In this work,a series of crystalline complexes of rare earth perchlorate coordinated with glutamic acid have been synthesized in water medium,and their thermodynamical data,including the heat capacity in low temperature range and the standard enthalpy of formation,were determined.These complexes were identified to be [RE2(Glu)2(H2O)8](ClO4)4.H2O (RE=Nd,Eu,Dy) by using thermogravimetric analysis (TG),differential thermal analysis (DTA),and chemical and elementary analyses.Their purity has been determined.No melting points were observed for all the three complexes.The heat capacity of the complexes was measured by an adiabatic calorimeter from 79 to 370 K.Abnormal heat capacity values were detected for two of the complexes and the decomposition range of one complex was found.The temperature,enthalpy change and entropy change of the decomposition processes of the three complexes were calculated.The polynomial equations of heat capacity in the experimental temperature range have been obtained by least squares fitting.The standard enthalpy of formation was determined by an isoperibol reaction calorimeter at 298.15 K.

  18. Microcalorimetric study about biological effect of a synthetic complex: La(Glu)(Im)6(ClO4)3.4HClO4.4H2O

    International Nuclear Information System (INIS)

    A complex of lanthanum perchloric acid coordinated with glutamic acid, La(Glu)(Im)6(ClO4)3.4HClO4.4H2O was synthesized and characterized. The biological effect of the complex was evaluated by microcalorimetry on the growth of E. coli DH5α. Power-time curves of the growth metabolism of E. coli DH5α were studied using a TAM Air Isothermal Microcalorimeter at 37 oC. From the power-time curves, the parameters such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (Pm) and the time of the maximum heat power (tm) were obtained. The results show that the concentrations of the complex affect obviously the growth metabolism of E. coli DH5α. The stimulatory effect on growth of E. coli DH5α was observed when the concentration of the complex was kept in the range of (0-0.5 μg mL-1). In contrast to the lower concentration, in the case of higher concentration of the complex (0.5-5.0 μg mL-1), an inhibitory effect occurred.

  19. Synthesis and Crystal Structure of Complex {[Cu(N-men)2(cda)2]·[Cu(N-men)2]((ClO4)2}(N-men = N-Methylethylenediamine,cda = Carbamyldicyanomethanide Anion)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Mononuclear complex {[Cu(N-men)2(cda)2]([Cu(N-men)2]((ClO4)2} was synthesized by sodium carbamyldicyanomethanide Na(cda), N-methylethylenediamine and hydrate copper perchlorate. The crystal belongs to the triclinic system, space group P ī with a = 7.229(2), b = 8.114(2), c = 15.936(4) (A), α = 80.511(4), β = 78.993(4), γ= 72.118(4)o, V = 867.6(3)(A)3, Z = 1, C20H44Cl2Cu2N14O10, Mr = 838.68, Dc = 1.605 g/cm3, F(000) = 434 and μ = 1.449 mm-1. The structure was refined to R = 0.0480 and wR = 0.1289 for 2503 observed reflections (I > 2σ(I)). In the complex there exist two kinds of coordination models for Cu (Ⅱ) ions. One is that the Cu (Ⅱ) ion is coordinated by four nitrogen atoms which are from two N-men molecules, and a slightly distorted square planar coordinate environment is formed around the Cu (Ⅱ) ion; the other is that the Cu (Ⅱ) ion is coordinated by six nitrogen atoms, of which four are from two N-men molecules and the left from nitrile groups, resulting in a distorted octahedron around the Cu (Ⅱ) ion. The deposition number of the crystal at CCDC is 161868.

  20. Solvato-polymorph of [(η6-C6H6)RuCl (L)]PF6 (L = (2,6-dimethyl-phenyl-pyridin-2-yl methylene amine)

    Science.gov (United States)

    Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard

    2016-06-01

    A half-sandwich complex salt of ruthenium containing the Schiff base ligand, 2, 6-dimethyl-N-(pyridin-2-ylmethylene)aniline has been synthesized and structurally characterized. The complex salt 1, [(η6-C6H6)RuCl(C5H4NCHdbnd N(2,6-(CH3)2C6H3)]PF6 was obtained from the reaction of the ruthenium arene precursor, [(η6- C6H6)Ru(μ-Cl)Cl]2 with the Schiff base in a 1:2 ratio followed by treatment with NH4PF6. Its acetone solvate 2, [(η6-C6H6)RuCl(C5H4NCHdbnd N (2, 6- (CH3)2C6H3)]PF6. (CH3)2CO was obtained by recrystallization of 1 from a solution of hexane and acetone. 1 and 2 crystallize in the monoclinic P21/c and P21/n space groups as blocks and as prisms respectively. The ruthenium centers in 1 and 2 are coordinated to the bidentate Schiff base, to a chloride atom, and to the arene ring to give a pseudo-octahedral geometry around them. The whole arrangement is referred to as the familiar three-legged piano stool in which the Schiff base and the Cl atom serve as the base while the arene ring serve as the apex of the stool. Polymorph 2 has an acetone molecule in the asymmetric unit. Of interest is the similar behavior of the solvate on heating which shows the crystals shuttering at about 531.6 and 523.4 K for 1 and 2 respectively.

  1. Synthesis, structure and gas-phase reactivity of the mixed silver hydride borohydride nanocluster [Ag3(μ3-H)(μ3-BH4)L(Ph)3]BF4 (L(Ph) = bis(diphenylphosphino)methane).

    Science.gov (United States)

    Zavras, Athanasios; Ariafard, Alireza; Khairallah, George N; White, Jonathan M; Mulder, Roger J; Canty, Allan J; O'Hair, Richard A J

    2015-11-21

    Borohydrides react with silver salts to give products that span multiple scales ranging from discrete mononuclear compounds through to silver nanoparticles and colloids. The cluster cations [Ag3(H)(BH4)L3](+) are observed upon electrospray ionization mass spectrometry of solutions containing sodium borohydride, silver(I) tetrafluoroborate and bis(dimethylphosphino)methane (L(Me)) or bis(diphenylphosphino)methane (L(Ph)). By adding NaBH4 to an acetonitrile solution of AgBF4 and L(Ph), cooled to ca. -10 °C, we have been able to isolate the first mixed silver hydride borohydride nanocluster, [Ag3(μ3-H)(μ3-BH4)L(Ph)3]BF4, and structurally characterise it via X-ray crystallography. Combined gas-phase experiments (L(Me) and L(Ph)) and DFT calculations (L(Me)) reveal how loss of a ligand from the cationic complexes [Ag3(H)(BH4)L3](+) provides a change in geometry that facilitates subsequent loss of BH3 to produce the dihydride clusters, [Ag3(H)2Ln](+) (n = 1 and 2). Together with the results of previous studies (Girod et al., Chem. - Eur. J., 2014, 20, 16626), this provides a direct link between mixed silver hydride/borohydride nanoclusters, silver hydride nanoclusters, and silver nanoclusters.

  2. Effective asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate to ethyl (R)-4-chloro-3-hydroxybutanoate by recombinant E. coli CCZU-A13 in [Bmim]PF6-hydrolyzate media.

    Science.gov (United States)

    He, Yu-Cai; Tao, Zhi-Cheng; Di, Jun-Hua; Chen, Liang; Zhang, Lin-Bing; Zhang, Dan-Ping; Chong, Gang-Gang; Liu, Feng; Ding, Yun; Jiang, Chun-Xia; Ma, Cui-Luan

    2016-08-01

    It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3wt%)-soaking rice straw at 30°C was used to form [Bmim]PF6-hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (>99% e.e.) with recombinant E. coli CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20mM) was employed to improve the reductase activity. Moreover, Hp-β-cyclodextrin (0.01mol Hp-β-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of (R)-CHBE from COBE by E. coli CCZU-A13 whole-cells. The yield of (R)-CHBE (>99% e.e.) from 800mM COBE was obtained at 100% in the [Bmim]PF6-hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20mM) and Hp-β-CD (8mM). In conclusion, an effective strategy for the biosynthesis of (R)-CHBE was successfully demonstrated.

  3. Study on Stability and Electrochemical Properties of Nano-LiMn1.9Ni0.1O3.99S0.01-Based Li-Ion Batteries with Liquid Electrolyte Containing LiPF6

    Directory of Open Access Journals (Sweden)

    Monika Bakierska

    2016-01-01

    Full Text Available Herein, we report on the stability and electrochemical properties of nanosized Ni and S doped lithium manganese oxide spinel (LiMn1.9Ni0.1O3.99S0.01, LMN1OS in relation to the most commonly used electrolyte solution containing LiPF6 salt. The influence of electrochemical reaction in the presence of selected electrolyte on the LMN1OS electrode chemistry was examined. The changes in the structure, surface morphology, and composition of the LMN1OS cathode after 30 cycles of galvanostatic charging/discharging were determined. In addition, thermal stability and reactivity of the LMN1OS material towards the electrolyte system were verified. Performed studies revealed that no degradative effects, resulting from the interaction between the spinel electrode and liquid electrolyte, occur during electrochemical cycling. The LMN1OS electrode versus LiPF6-based electrolyte has been indicated as an efficient and electrochemically stable system, exhibiting high capacity, good rate capability, and excellent coulombic efficiency. The improved stability and electrochemical performance of the LMN1OS cathode material originate from the synergetic substitution of LiMn2O4 spinel with Ni and S.

  4. Magnetism and Pressure-Induced Superconductivity of Checkerboard-Type Charge-Ordered Molecular Conductor β-(meso-DMBEDT-TTF2X (X = PF6 and AsF6

    Directory of Open Access Journals (Sweden)

    Yutaka Nishio

    2012-11-01

    Full Text Available The metallic state of the molecular conductor β-(meso-DMBEDT-TTF2X (DMBEDT-TTF = 2-(5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene-5,6-dihydro-5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin, X = PF6, AsF6 is transformed into the checkerboard-type charge-ordered state at around 75–80 K with accompanying metal-insulator (MI transition on the anisotropic triangular lattice. With lowering temperatures, the magnetic susceptibility decreases gradually and reveals a sudden drop at the MI transition. By applying pressure, the charge-ordered state is suppressed and superconductivity appears in β-(meso-DMBEDT-TTF2AsF6 as well as in the reported β-(meso-DMBEDT-TTF2PF6. The charge-ordered spin-gapped state and the pressure-induced superconducting state are discussed through the paired-electron crystal (PEC model, where the spin-bonded electron pairs stay and become mobile in the crystal, namely the valence-bond solid (VBS and the resonant valence bonded (RVB state in the quarter-filled band structure.

  5. Effective asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate to ethyl (R)-4-chloro-3-hydroxybutanoate by recombinant E. coli CCZU-A13 in [Bmim]PF6-hydrolyzate media.

    Science.gov (United States)

    He, Yu-Cai; Tao, Zhi-Cheng; Di, Jun-Hua; Chen, Liang; Zhang, Lin-Bing; Zhang, Dan-Ping; Chong, Gang-Gang; Liu, Feng; Ding, Yun; Jiang, Chun-Xia; Ma, Cui-Luan

    2016-08-01

    It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3wt%)-soaking rice straw at 30°C was used to form [Bmim]PF6-hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (>99% e.e.) with recombinant E. coli CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20mM) was employed to improve the reductase activity. Moreover, Hp-β-cyclodextrin (0.01mol Hp-β-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of (R)-CHBE from COBE by E. coli CCZU-A13 whole-cells. The yield of (R)-CHBE (>99% e.e.) from 800mM COBE was obtained at 100% in the [Bmim]PF6-hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20mM) and Hp-β-CD (8mM). In conclusion, an effective strategy for the biosynthesis of (R)-CHBE was successfully demonstrated. PMID:27155796

  6. Substituent effects on spin state in a series of mononuclear manganese(III) complexes with hexadentate Schiff-Base ligands.

    Science.gov (United States)

    Gildea, Brendan; Harris, Michelle M; Gavin, Laurence C; Murray, Caroline A; Ortin, Yannick; Müller-Bunz, Helge; Harding, Charles J; Lan, Yanhua; Powell, Annie K; Morgan, Grace G

    2014-06-16

    Eleven new mononuclear manganese(III) complexes prepared from two hexadentate ligands, L1 and L2, with different degrees of steric bulk in the substituents are reported. L1 and L2 are Schiff bases resulting from condensation of N,N'-bis(3-aminopropyl)ethylenediamine with 3-methoxy-2-hydroxybenzaldehyde and 3-ethoxy-2-hydroxybenzaldehyde respectively, and are members of a ligand series we have abbreviated as R-Sal2323 to indicate the 323 alkyl connectivity in the starting tetraamine and the substitution (R) on the phenolate ring. L1 hosts a methoxy substituent on both phenolate rings, while L2 bears a larger ethoxy group in the same position. Structural and magnetic properties are reported in comparison with those of a previously reported analogue with L1, namely, [MnL1]NO3, (1e). The BPh4(-) and PF6(-) complexes [MnL1]BPh4, (1a), [MnL2]BPh4, (2a), [MnL1]PF6, (1b'), and [MnL2]PF6, (2b), with both ligands L1 and L2, remain high-spin (HS) over the measured temperature range. However, the monohydrate of (1b') [MnL1]PF6·H2O, (1b), shows gradual spin-crossover (SCO), as do the ClO4(-), BF4(-), and NO3(-) complexes [MnL1]ClO4·H2O, (1c), [MnL2]ClO4, (2c), [MnL1]BF4·H2O, (1d), [MnL2]BF4·0.4H2O, (2d), [MnL1]NO3, (1e), and [MnL2]NO3·EtOH, (2e). The three complexes formed with ethoxy-substituted ligand L2 all show a higher T1/2 than the analogous complexes with methoxy-substituted ligand L1. Analysis of distortion parameters shows that complexes formed with the bulkier ligand L2 exhibit more deformation from perfect octahedral geometry, leading to a higher T1/2 in the SCO examples, where T1/2 is the temperature where the spin state is 50% high spin and 50% low spin. Spin state assignment in the solid state is shown to be solvate-dependent for complexes (1b) and (2e), and room temperature UV-visible and NMR spectra indicate a solution-state spin assignment intermediate between fully HS and fully low spin in 10 complexes, (1a)-(1e) and (2a)-(2e). PMID:24901836

  7. On the changes of the structure of perchlorate (ClO4-)-degrading bacterial communities under heterotrophic conditions%异养条件下高氯酸盐降解细菌群落变化研究

    Institute of Scientific and Technical Information of China (English)

    谢宇轩; 关翔宇; 王阳; 王鹤立

    2014-01-01

    了解特定环境中高氯酸盐(ClO4-)降解菌的群落组成,对ClO4-的降解具有重要的指导意义.通过添加醋酸盐作为电子供体降解ClO4-,利用高通量测序(HiSeq 2000)的方法获得了复杂环境中生物群落的组成,对比了降解前后菌种结构的变化.结果表明,补充醋酸盐的降解体系(Acetate Degradation,AD)将10 mg/L ClO4-降至检出限以下需100 h.降解完毕后代表性的ClO4-降解菌Dechloromonas的相对丰度为0.2%,与原始活性污泥相比无明显差别;另一典型ClO2降解菌脱氯菌属Azospira相对丰度为3.2%;一些同时参与ClO4-降解和脱氮作用的细菌如假单胞菌属Pseudomonas也有检出,相对丰度为8%.异养条件下ClO4-降解是假单胞菌属Pseudomonas和脱氨菌属Azospira起主导作用.AD体系内菌种多样性小于原始活性污泥.电子供体的加入使活性污泥类的混合体系内生物群落结构单一化,使降解基质具备了在特定环境下针对某种污染物降解的能力.

  8. Epoxidação do óleo de soja com o sistema catalítico [MoO2(acac2]/TBHP EM [bmim][PF6

    Directory of Open Access Journals (Sweden)

    Maritana Farias

    2012-01-01

    Full Text Available Epoxidation of soybean oil was investigated using 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] ionic liquid as biphasic medium with molybdenum(VI acetylacetonate complex and tert-butyl hydroperoxide TBHP as oxidizing agent. Reaction conditions were molar ratio TBHP:number of double bonds of oil:catalyst of 100:100:1, reaction temperature of 60 ºC and reaction time between 2 and 24 h. The proposed system showed catalytic activity for epoxidation reactions under tested conditions. Reuse of ionic liquid/catalyst system for epoxidation reactions was also investigated. Evaluation of epoxidation observed in this catalytic system was done by quantitative ¹H NMR data.

  9. Exceptionally long-lived light-emitting electrochemical cells: multiple intra-cation π-stacking interactions in [Ir(C^N)2(N^N)][PF6] emitters

    OpenAIRE

    Buenzli, Andreas M.; Constable, Edwin C.; Housecroft, Catherine E.; Prescimone, Alessandro; Zampese, Jennifer A.; Longo, Giulia; Gil-Escrig, Lidon; Pertegas, Antonio; Orti, Enrique; Bolink, Henk J.

    2015-01-01

    A series of cyclometalated iridium(III) complexes [Ir(C^N)2(N^N)][PF6] (N^N = 2,2′-bipyridine (1), 6-phenyl-2,2′-bipyridine (2), 4,4′-di-tert-butyl-2,2′-bipyridine (3), 4,4′-di-tert-butyl-6-phenyl-2,2′-bipyridine (4); HC^N = 2-(3-phenyl)phenylpyridine (HPhppy) or 2-(3,5-diphenyl)phenylpyridine (HPh2ppy)) are reported. They have been synthesized using solvento precursors so as to avoid the use of chlorido-dimer intermediates, chloride ion contaminant being detrimental to the performance of [Ir...

  10. Synthesis, crystal structure and magnetic properties of a thiocyanate bridged dinuclear copper(Ⅱ) complex:[μ-SCN Cu dien]2 (ClO4)2%硫氰酸根桥连双核铜配合物[μ-(SCN)Cu(dien)]2(ClO4)2的合成、晶体结构和磁性研究

    Institute of Scientific and Technical Information of China (English)

    米春喜; 胡怀明

    2004-01-01

    合成了硫氰酸根桥连双核铜配合物[μ-(SCN)Cu(dien)]2(ClO4)2,测定了它的晶体结构.晶体为三斜晶系,P-1空间群,a=0.746 5(2),b=0.748 4(2),c=1.182 2(2)nm,α=90.51(3),β=105.39(3),γ=109.06(3)°,V=0.598 5(2)nm3,Dc=1.799 Mg/m3,μ=2.227 mm-1,F(000)=330,Z=1.最小二乘修正得R1=0.0325,wR2=0.0906.结构由高氯酸根离子和双核铜配正离子组成,两个铜离子由两个硫氰酸根离子桥连,两个铜离子之间的距离为0.5512(2)nm.每个铜离子与二乙烯三胺的三个氮原子和硫氰酸根的一个氮原子在赤道平面上配位,另一个硫氰酸根的一个硫原子和高氯酸根的一个氧原子在轴向配位,形成了畸变的八面体配位几何构型.Cu-N键长在0.195 0(1)~0.20l 8(1)nm范围内,Cu-S键长0.276 6(1),Cu-O键长0.288 4(2)nm.研究了75~300K温度范围内固体样品的磁性,表明在铜离子间存在着反铁磁相互作用.

  11. Synthesis and Electrochemical Properties of {[(bpy)2Ru(dpp)]2RhCl2}(PF6)5: A Light Absorber - Electron Collector - Light Absorber Triad AND Development and Evaluation of Integrated Molecular Modeling, Synthesis, and Characterization Laboratory Experiments for the Undergraduate Chemistry Curriculum

    OpenAIRE

    Bullock, Elizabeth Raub

    2000-01-01

    The research detailed herein has been conducted in two different areas. The first research goal was to develop and study a supramolecular system coupling two light absorber units to a central metal site capable of collecting two electrons; this has been accomplished. The complex {[(bpy)2Ru(dpp)]2RhCl2}(PF6)5 was synthesized and characterized using electrochemistry and electronic absorption spectroscopy. The electrochemical properties of {[(bpy)2Ru(dpp)]2RhCl2}(PF6)5 were probed with c...

  12. A perspective on coatings to stabilize high-voltage cathodes: LiMn1.5Ni0.5O4 with subnanometer Lipon cycled with LiPF6 electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoongu [ORNL; Dudney, Nancy J [ORNL; Chi, Miaofang [ORNL; Martha, Surendra K [ORNL; Nanda, Jagjit [ORNL; Veith, Gabriel M [ORNL; Liang, Chengdu [ORNL

    2013-01-01

    High voltage Li-ion cathodes push the limits of stability for both cathode and electrolyte. Here subnanometer coatings of an amorphous thin film electrolyte (Lipon) improved the room temperature and 60 C cycling stability of a LiMn1.5Ni0.5O4 spinel cathode when charged to 4.9V with a standard LiPF6 carbonate electrolyte. The cathodes delivered superior C-rate performances up to a 5C discharge, when compared to the uncoated cathodes. Enhanced performance extended for at least 100 cycles. Electrochemical impedance spectroscopy indicates that Lipon slows the increase of interface resistance. Thicker 1-3nm Lipon coatings are sufficiently insulating as to block electronic transport to the cathode particles. Thick coatings also slow Mn dissolution. Results suggest that Lipon may act to scavenge impurities or block active sites that promote electrolyte decomposition. While greatly improved by the Lipon coating, this cathode is not sufficiently stable for long cycle life applications. Further work is needed to assess if and what surface coatings will ultimately stabilize the high voltage cathodes. Comments include insight from other studies of Lipon coated cathodes and directions for future research.

  13. Fire behavior of carbonates-based electrolytes used in Li-ion rechargeable batteries with a focus on the role of the LiPF6 and LiFSI salts

    Science.gov (United States)

    Eshetu, Gebrekidan Gebresilassie; Bertrand, Jean-Pierre; Lecocq, Amandine; Grugeon, Sylvie; Laruelle, Stephane; Armand, Michel; Marlair, Guy

    2014-12-01

    A detailed investigation of the combustion behavior of LiPF6 or LiFSI-based carbonate electrolytes was conducted with the objective of getting better knowledge of lithium-ion battery system fire induced thermal and chemical threats. The well-controlled experimental conditions provided by the Tewarson calorimeter have enabled the accurate evaluation of fire hazard rating parameters such as heat release rate and effective heat of combustion and the quantification of toxic effluents (HF, SO2, NOx…). Results have shown that all the electrolytes tested burn in phases depending on the flammability nature of their mixture constituents. The first stage of combustion is solely governed by the more volatile solvent (linear carbonate) and the influence of adding salt comes into effect predominantly in the second stage. It has been also shown that combustion enthalpy of electrolytes lies in the solvent mixture, irrespective of the salt added. The fire induced toxicity in well-ventilated conditions is found to be mainly dictated by the salt and its chemical structure, showing very limited concerns that emanate from the organic solvents.

  14. Synthesis, Crystal Structures and Properties of Tetrametallic Complexes: [M2(phen)4(FCA)2](ClO4)2o(H2O)2 (M=Zn or Co, phen= 1,10-phenanthroline, FCA =anion of 3-ferrocenyl-2-crotonic acid)

    Institute of Scientific and Technical Information of China (English)

    YANG Jia-Xiang; HU Zhang-Jun; ZHANG Ze; TIAN Yu-Peng; LIU Qing-Liang; CHANTRAPROMMA Suchada; FUN Hoong-Kun

    2005-01-01

    Two new complexes [Zn2(phen)4(FCA)2](ClO4)2·(H2O)2 (1) and [Co2(phen)4 (FCA)2](ClO4)2·(H2O)2 (2) (FCA =anion of 3-ferrocenyl-2-crotonic acid, phen= 1,10-phenanthroline) have been synthesized, and characterized by elemental analysis, IR, UV-Vis spectra, thermal analyses, and single-crystal X-ray diffraction. Two M(Ⅱ) (M=Zn or Co) ions are bridged by two FCA anions with syn-anti bridging ligands, leading to dimeric cores,[M2(phen)4(FCA)2]2+, and each M(Ⅱ) ion is six-coordinated in a distorted octahedral geometry by two chelate phen ligands and two μ2-carboxylate oxygen atoms from two FCA groups. The M(Ⅱ)…M(Ⅱ) intradimer distances are 0.4391 and 0.4462 nm in 1 and 2, respectively. Electrochemical properties of the complexes have been discussed.

  15. Synthesis and Thermal decomposition of μ-Oxalato-bis[(N, N'-dimethylformamide)(1,10-phenanthroline)copper(Ⅱ)]bis(perchlorate)%[Cu2(C2O4)(C12H8N2)2(C3H7NO)2](ClO4)2配合物的合成及其热分解

    Institute of Scientific and Technical Information of China (English)

    刘慧; 徐寿相; 李艳飞; 汪海东

    2011-01-01

    The title centrosymmetric binuclear complex,[Cu2(C2O4)(C12 HsN2)2(C3H7NO)2](ClO4)2(1),was synthesized by the reaction of 1,10-phenanthroline,2,5-dihydroxy-1,4-dithiane and Cu(ClO4)2 · 6 H2O.Then the complex was characterized by IR spectra and elemental analysis.The thermal decomposition of the complex was studied by TG technique under dynamic nitrogen atmosphere.The thermal decomposition mechanism of the complex has been determined on the basis of thermal analysis.%以邻菲罗啉、2,5二羟基-1,4-二噻烷和Cu(ClO4)2.6H2O为原料,合成了中心对称的双核配合物[Cu2(C2O4)(C12H,N2)2(C3 H7NO)2](ClO4)2(1).通过红外光谱、元素分析等分析测试手段对其进行了表征;借助TG-DTG技术在氮气气氛下研究了配合物的热分解情况,并根据热分析结果确定了其热分解机理.

  16. Preparation and Performances of Room Molten Salt as Electrolyte in Carbon-carbon Capacitor Based on LiPFe and Trifluoroacetamide%LiPF6/三氟乙酰胺室温熔盐的制备及在碳-碳电容器中的性能

    Institute of Scientific and Technical Information of China (English)

    左晓希; 李奇; 刘建生; 肖信; 范成杰; 南俊民

    2012-01-01

    利用LiPF6和三氟乙酰胺为前驱物,制备了低共熔温度约为-62℃的室温熔盐,并测试了该熔盐作为碳-碳电化学电容器(EDLCs)电解液时的性能。其中,使用差示扫描量热法(DSC)和红外光谱法(FTIR)分析了不同LiPF6和三氟乙酰胺配比熔盐的热稳定性,拟制了该二元组分的共熔相图,认为LiPF6和三氟乙酰胺极性基团间的氢键作用促成了室温熔盐的形成。循环伏安(CV)、交流阻抗(EIS)和电导等测定结果表明,所制备的LiPF6/三氟乙酰胺电解液的室温电导率为1.30mS/cm,电化学窗口大于5.6V,大于60℃的使用温度,作为电解液可满足碳-碳EDLCs的使用要求。%A novel room molten salt with an eutectic temperature of about -62℃ is prepared using LiPF6 and trifluoroacetamide as precursors. And then its performances are evaluated in carbon-carbon electrochemical double layer capacitor (EDLC) as electrolyte. The thermal properties of the complex electrolyte with different molar ratios are characterized and then the liquid-solid phase diagram is presented by using differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR). The hydrogen bonding interaction between LiPF6 and trifluoroacetamide molecules is attributed to the formation of the as-prepared molten salt. In addition, the results of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and conductance tests show that the as-prepared LiPF6/trifluoroacetamide electrolyte has a maximum conductance at room temperature, i.e. 1.30 mS/cm, a stable electrochemical window of ca. 5.6 V, an applicable temperature of more than 60℃, suggesting it is a promising electrolyte candidate for carbon-carbon EDLCs.

  17. 离子液体[C4mim][PF6]与N,N-二甲基甲酰胺二元混合物在298.15 K~318.15 K的密度和粘度%Densities and Viscosities of the Ionic Liquid [C4mim][PF6]+N,N-dimethylformamide Binary Mixtures at 293.15 K to 318.15 K

    Institute of Scientific and Technical Information of China (English)

    耿彦芳; 王腾芳; 虞大红; 彭昌军; 刘洪来; 胡英

    2008-01-01

    Viscosities and densities for 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and N,N-dimethylformamide (DMF) binary mixtures have been measured at the temperature range from 293.15 K to 318.15 K. It is shown that the viscosities and densities decrease monotonously with temperature and the content of DME Various correlation methods including Arrhenius-like equation, Seddon et al.'s equation, Redlich-Kister equation with four parameters, and other empirical equations were applied to evaluate these experimental data. A model based on an equation of state for estimating the viscosity of mixtures containing ionic liquids were proposed by coupling with the excess Gibbs free energy model of viscosity, which can synchronously calculate the viscosity and the molar volume. The results show that the model gives a deviation of 8.29% for the viscosity, and a deviation of 1.05% for the molar volume when only one temperature-independent adjustable parameter is adopted. The cor-relation accuracy is further improved when two parameters or one temperature-dependent parameter is used.

  18. Host-guest supramolecular interactions in the coordination compounds of 4,4'-azobis(pyridine) with MnX2 (X = NCS–, NCNCN–, and PF6(–)): structural analyses and theoretical study.

    Science.gov (United States)

    Kar, Paramita; Biswas, Rituparna; Drew, Michael G B; Frontera, Antonio; Ghosh, Ashutosh

    2012-02-01

    Three new Mn(II) coordination compounds {[Mn(NCNCN)(2)(azpy)]·0.5azpy}(n) (1), {[Mn(NCS)(2)(azpy)(CH(3)OH)(2)]·azpy}(n) (2), and [Mn(azpy)(2)(H(2)O)(4)][Mn(azpy)(H(2)O)(5)]·4PF(6)·H(2)O·5.5azpy (3) (where azpy = 4,4'-azobis(pyridine)) have been synthesized by self-assembly of the primary ligands, dicyanamide, thiocyanate, and hexafluorophosphate, respectively, together with azpy as the secondary spacer. All three complexes were characterized by elemental analyses, IR spectroscopy, thermal analyses, and single crystal X-ray crystallography. The structural analyses reveal that complex 1 forms a two-dimensional (2D) grid sheet motif. These sheets assemble to form a microporous framework that incorporates coordination-free azpy by host-guest π···π and C-H···N hydrogen bonding interactions. Complex 2 features azpy bridged one-dimensional (1D) chains of centrosymmetric [Mn(NCS)(2)(CH (3)OH)(2)] units which form a 2D porous sheet via a CH(3)···π supramolecular interaction. A guest azpy molecule is incorporated within the pores by strong H-bonding interactions. Complex 3 affords a 0-D motif with two monomeric Mn(II) units in the asymmetric unit. There exist π···π, anion···π, and strong hydrogen bonding interactions between the azpy, water, and the anions. Density functional theory (DFT) calculations, at the M06/6-31+G* level of theory, are used to characterize a great variety of interactions that explicitly show the importance of host-guest supramolecular interactions for the stabilization of coordination compounds and creation of the fascinating three-dimensional (3D) architecture of the title compounds. PMID:22272694

  19. Effects of Rut-bpy (Cis-[Ru(bpy2(SO3(NO]PF 6, a novel nitric oxide donor, in L-NAME-induced hypertension in rats Efeitos do Rut-bpy (Cis-[Ru(bpy2(SO3(NO]PF 6, um novo doador de óxido nítrico, na hipertensão induzida com L-NAME em ratos

    Directory of Open Access Journals (Sweden)

    Marcio Wilker Soares Campelo

    2011-01-01

    Full Text Available PURPOSE: To evaluate the effect of Rut-bpy (Cis-[Ru(bpy2(SO3(NO]PF 6, a novel nitric oxide donor in Nω-nitro-L-arginine methyl ester (L-NAME-induced hypertensive rats. METHODS: Twenty-four male Wistar rats were randomly assigned to four groups (n=6, named according to the treatment applied (G1-Saline, G2-Rut-bpy, G3-L-NAME and G4-L-NAME+Rut-bpy. L-NAME (30 mg/Kg was injected intraperitoneally 30 minutes before the administration of Rut-bpy (100 mg/Kg. Mean abdominal aorta arterial blood pressure (MAP was continuously monitored. RESULTS: Mean arterial blood pressure (MAP in G3 rats rose progressively, reaching 147±16 mmHg compared with 100±19 mm Hg in G1 rats (pOBJETIVO: Avaliar o efeitos do Rut-bpy (Cis-[Ru (bpy2(SO3(NO] PF6, um novo doador de óxido nítrico, em ratos hipertensos induzidos pelo éster metílico de N-nitro-L-arginina (L-NAME. MÉTODOS: Vinte e quatro ratos Wistar machos foram distribuídos aleatoriamente em quatro grupos (n = 6, nomeados de acordo com o tratamento aplicado (G1-Salina, G2-Rut-bpy, G3-L-NAME e G4-L-NAME+Rut -bpy. L-NAME (30 mg / Kg foi injetado por via intraperitoneal 30 minutos antes da administração de Rut-bpy (100 mg / kg. A pressão arterial média (PAM da aorta abdominal foi monitorada continuamente. RESULTADOS: A pressão arterial média (PAM em ratos do grupo G3 subiu progressivamente, chegando a 147 ±16 mm Hg, em comparação com 100 ±19 mm Hg em ratos do G1 (p <0,05. Em ratos G4, tratados com L-NAME + Rut-bpy, a PAM atingiu 149±11 milímetros de Hg, enquanto no G2 (ratos tratados com Rut bpy os valores da PAM foram 106 ±11 mm Hg. No G1 esses valores decresceram progressivamente, atingindo 87±14 mm Hg após 30 minutos. Um achado importante foi a manutenção da PAM durante todo o experimento em ratos do grupo G2. CONCLUSÃO: O uso de Rut bpy não diminui a PAM em ratos hipertensos por L-NAME. No entanto, quando ele é usado em ratos anestesiados, hipotensos, uma pressão arterial estável

  20. 高氯酸碳酰肼盐与硝酸碳酰肼盐系列化合物的晶格能与感度性能关系%Relationship between Lattice Energy and Sensitivity of [M(CHZ)3](NO3)2 and [M(CHZ)3](ClO4)2 (M=Mn, Zn, Ni)

    Institute of Scientific and Technical Information of China (English)

    郑秋雨; 乔小晶; 邵风雷; 张建国; 杨利

    2009-01-01

    为了研究晶格能与感度之间的关系,采用微热量计测定了[M(CHZ)3](NO3)2和[M(CHZ)3](ClO4)2 (M=Mn, Zn, Ni)在去离子水中的溶解焓并计算出它们的标准摩尔溶解焓,根据卡普廷斯基经验公式计算了它们的晶格能,得出配阳离子半径[M(CHZ)3]2+ (M=Mn, Zn, Ni)分别为2.12(A), 1.89(A)和2.70(A);讨论了晶格能与机械感度之间的关系: 相同外阴离子系列中配合物的晶格能越大,感度越小,并且高氯酸碳酰肼盐要比相应的硝酸碳酰肼盐的晶格能低,感度最高的为[Ni(CHZ)3](ClO4)2,最钝感的为[Zn(CHZ)3](NO3)2.%The standard molar enthalpies of series of energetic coordination compounds solution with carbohydrazide as ligand and nitrate or perchlorate as anion in deionized water were measured by a Setaram C80II microcalorimeter at 298.15 K. Based on these values, their lattice energy were calculated through Kapustinkii formula, meanwhile the thermochemistry radius of [M(CHZ)3]2+ (M=Mn, Zn, Ni) was gained. The relationship between lattice energy and impact sensitivity or friction sensitivity was discussed. Results show that the lattice energy of perchlorate are smaller than their corresponding nitrate, thus the perchlorate are more sensitive.

  1. Microwave assisted preparation of TiO2 catalyst in ionic liquid and its activity capability%[Bmim]BF4离子液体中微波辅助制备TiO2催化剂及活性研究

    Institute of Scientific and Technical Information of China (English)

    杨艳琼; 徐成东

    2011-01-01

    Ionic liquid [ Bmim ] BF4 had been [ Bmim] BF4 as reactive medium, TiO2 catalyst were prepared by microwave irradiation. With the prepared by microwave irradiating. XRD, IR, TG were employed to characterize the catalyst. With methyl orange as degradation agent and ultraviolet lamp as light source, the photo - catalytic capability of TiO2 was tested. that the better condition of preparing TiO2 is 2.0mL [ Bmim ] BF4, microwave temperature 70℃ and reactive time 35min and the photo -catalytic degrada methyl orange could reach 93.7% in 1.5h at the conditions.%采用微波加热合成离子液体[Bmim]BF4,以该离子液体为反应介质,在微波辐射条件下制备TiO5光催化剂,在高压汞灯下用甲基橙溶液测试其光催化降解性能;并用XRD,IR,TG对其进行测试和表征。结果表明,制备TiO2光催化剂的较佳条件是:离子液体2.0mL,微波辐射功率600W、反应温度70℃、反应时间35min。并且用[Bmim]BF4作为反应介质,能够显著提高TiO2的光催化活性,所制备的TiO5不需要经过高温煅烧,就表现出极高的光催化活性。该催化剂对甲基橙的降解率在1.5h就可达到93.7%。

  2. Excess Molar Volume, Refractive Index and Viscosity of N-Butylpyridinium Tetrafluoroborate Ionic Liquid + Methanol Binary System%离子液体[BPy]BF4和甲醇二元混合体系的超额摩尔体积、折射率和黏度

    Institute of Scientific and Technical Information of China (English)

    许映杰; 黄钗英; 李浩然

    2011-01-01

    合成了室温离子液体N-丁基吡啶四氟硼酸盐([BPy]BF4),通过核磁共振1H-NMR和红外光谱IR对其结构进行了表征.在298.15 K和常压下,采用U形振荡管密度计测定[BPy]BF4-甲醇体系的密度;用阿贝尔折射仪测定了该二元混合体系在相同温度和压力下的折射率;用乌氏黏度计测定了该二元混合体系在相同温度和压力下的黏度,并由密度数据计算出超额摩尔体积(VE)、由折射率数据计算出了折射率改变值(△nD)、由黏度数据计算出了体系的黏度B系数.结果表明:[BPy]BF4-甲醇体系的VE在全浓度范围内为负值,而△nD在全浓度范围内为正值,两者均在摩尔分数x1≈0.4处出现极值;采用Redlich-Kister方程对VE、△nD与组成的关系进行了关联,最大标准偏差小于3%,说明此方程可适用于回归该二元体系上述的物性数据.由Jones-Dole方程计算出体系的黏度B系数为0.35608,这表明甲醇有效地降低了离子液体的黏度.%Room temperature ionic liquid N-butylpyridinium tetrafluoroborate ([BPy]BF4) was synthesized, and its structure was characterized and confirmed by 1H-NMR and IR. The densities and refractive indices of binary mixtures ([BPy]BF4+methanol) with different compositions were determined at T= 298.15 K and under atmospheric pressure by using a vibrating U-shaped sample tube densimeter and semi-automatic refractometer,respectively. The viscosities of the mixtures were also determined at T= 298.15 K and under atmospheric pressure by using Ubbelohde Suspended-level viscometer. Density values were used in the calculation of the excess molar volumes (V E), and the refractive indices were used to calculate the changes of refractive index (△nD). The achieved viscosities were used to calculate the viscosity B coefficient of the mixtures. The results show that the values of VE are negative over the entire composition range, while the △nD are positive. When the mole fraction of [BPy]BF4

  3. Primary retention following nuclear recoil in β-decay: Proposed synthesis of a metastable rare gas oxide (38ArO4) from (38ClO4−) and the evolution of chemical bonding over the nuclear transmutation reaction path

    International Nuclear Information System (INIS)

    Argon tetroxide (ArO4) is the last member of the N=50 e– isoelectronic and isosteric series of ions: SiO44−, PO43−, SO42−, and ClO4−. A high level computational study demonstrated that while ArO4 is kinetically stable it has a considerable positive enthalpy of formation (of ∼298 kcal/mol) (Lindh et al., 1999. J. Phys. Chem. A 103, pp. 8295–8302) confirming earlier predictions by Pyykkö (1990. Phys. Scr. 33, pp. 52–53). ArO4 can be expected to be difficult to synthesize by traditional chemistry due to its metastability and has not yet been synthesized at the time of writing. A computational investigation of the changes in the chemical bonding of chlorate (ClO4−) when the central chlorine atom undergoes a nuclear transmutation from the unstable artificial chlorine isotope 38Cl to the stable rare argon isotope 38Ar through β-decay, hence potentially leading to the formation of ArO4, is reported. A mathematical model is presented that allows for the prediction of yields following the recoil of a nucleus upon ejecting a β-electron. It is demonstrated that below a critical angle between the ejected β-electron and that of the accompanying antineutrino their respective linear momentums can cancel to such an extent as imparting a recoil to the daughter atom insufficient for breaking the Ar–O bond. As a result, a primary retention yield of ∼1% of ArO4 is predicted following the nuclear disintegration. The study is conducted at the quadratic configuration interaction with single and double excitations [QCISD/6−311+G(3df)] level of theory followed by an analysis of the electron density by the quantum theory of atoms in molecules (QTAIM). Crossed potential energy surfaces (PES) were used to construct a PES from the metastable ArO4 ground singlet state to the Ar–O bond dissociation product ArO3+O(3P) from which the predicted barrier to dissociation is ca. 22 kcal/mol and the exothermic reaction energy is ca. 28 kcal/mol [(U)MP2/6–311+G(d)]. - Highlights: • Mathematical model for the yield of primary retention after β-decay. • The nature of metastable chemical bonding in thermodynamically unstable compounds. • The changes in the nature of chemical bond upon nuclear transmutation. • Synthetic protocol of metastable rare gas oxides (ArO4) from a hot chemistry route

  4. Crystal and molecular structure of four copper(II) ethylenediaminedisuccinates, [Cu2(RR,SS-Edds)] . 6H2O, Ba2[Cu(RR,SS-Edds)](ClO4)2 . 8H2O, Ba[Cu(SS-HEdds)]ClO4 . 2H2O, and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 . 6H2O

    International Nuclear Information System (INIS)

    Four Cu(II) complexes with the RR,SS-Edds4- and SS-HEdds3- anions are synthesized, and their crystal structures are studied. In the compounds [Cu2(RR,SS-Edds)] . 6H2O (I) and Ba2[Cu(RR,SS-Edds)](ClO4)2 . 8H2O (II), the ligand forms hexacoordinate chelate [Cu(Edds)]2- complexes with the N atoms and O atoms of the propionate groups in the equatorial positions and the O atoms of the acetate groups in the axial vertices. In the compounds Ba[Cu(SS-HEdds)]ClO4 . 2H2O (III) and Ba3[Cu2(RR,SS-Edds)2](ClO4)2 . 6H2O (IV), one of the propionate arms, the protonated arm in III and the deprotonated arm in IV, does not enter into the coordination sphere of the Cu atom. An acetate arm moves to its position in the equatorial plane, and the free axial vertex is occupied by an O atom of the perchlorate ion. In I-IV, the lengths of the equatorial Cu-N and Cu-O bonds fall in the ranges 1.970-2.014 and 1.921-1.970 A, respectively. The axial Cu-O bonds with the acetate groups and ClO4- anions are elongated to 2.293-2.500 and 2.727-2.992 A, respectively. In structure I, the second Cu atom acts as a counterion forming bonds with the O atoms of two water molecules and three O atoms of the Edds ligands. In II-IV, the Ba2+ cations are hydrated and bound to the O atoms of the anionic complexes and (except for one of the cations in IV) ClO4- anions. The coordination number of the Ba cations is nine. The structural units in I-IV are connected into layers. In I, an extended system of hydrogen bonds links the layers into a framework. In II and III, the layers are linked only by weak hydrogen bonds, one bond per structural unit. In IV, ClO4- anions are bound to the Ba and Cu atoms of neighboring layers, thus serving as bridges between the layers.

  5. Synthesis, crystal structure and thermochemical behaviour of complex of host-guest type [(LH2)(BF4)2·H2O] (L=racemate-5,7,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)

    International Nuclear Information System (INIS)

    Interaction of BF3·(C2H5)2O with racemate 5,7,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane in the presence of moisture of air results in [(LH2)(BF4)2·H2O] complex formation structure of which is determined by the method of x-ray diffraction analysis and is confirmed by thermogravimetry data. Crystal of the complex are monoclinic, space group - P21/n, a=25.570(7), b=11.231(5), c=8,715(4) A. Structure is built from two-charged organic cations of tetraazamacrocycle, tetrafluoroborate anions and water molecules in correlation 1:2:1 combined by hydrogen bond system in which all four nitrogen atoms of macrocycle performs the function of proton donors. Macrocycle in the complex takes a symmetry close by C2

  6. Synthesis, Crystal Structure and Polyphenol Oxidase Activities Study of [Cu(NTB)Cl] ClO4·2.5CH3 OH%[Cu(NTB)Cl]ClO4·2.5CH3OH的合成、晶体结构和多酚氧化酶活性研究

    Institute of Scientific and Technical Information of China (English)

    邱江华; 王光辉; 廖展如; 孟祥高

    2008-01-01

    合成了配合物[Cu(NTB)Cl]ClO4·2.5CH3OH(NTB为N,N,N-三(2(-苯并咪唑甲基)胺),并进行了紫外可见光谱、元素分析、循环伏安和单晶X射线衍射分析等表征.用UV-Vis.研究了以邻苯二酚、邻苯三酚为底物时配合物的多酚氧化酶活性,结果表明:配合物的多酚氧化酶活性符合米氏方程曲线;在pH为8.0和30℃的条件下,配合物催化邻苯三酚和邻苯二酚反应的转化数分别为88.2 h-1和0.54 h-1.通过动力学数据比较发现,邻苯三酚比邻苯二酚更容易氧化,而且它们的催化氧化速率都随着pH的升高而增大.%The title complex [ Cu (NTB) Cl ] ClO4 2.5 CH3 OH (NTB=Tris (benzimidazolyl-2-methyl) amine) has been synthesized and characterized by UV-Vis.,elemental analysis,cyclic voltammetry and single crystal X-ray diffraction anal-ysis.Polyphenol oxidase activities toward pyrogallol and catechol have been studied spectroscopically. Their kinetics obey the Michaelis-Menten equation. The turnover numbers of the complex toward pyrogallol are 88.2 h-1 and 0.54 h-1 for cate-chol at pH 8.0 and 30 ℃. Compared with the kinetic data,it is apparent that pyrogallol oxidation is easier than catechol,and catalytic activities increase with increasing of pH values.

  7. Sulfur-containing trinuclear arene ruthenium clusters

    OpenAIRE

    Tschan, Mathieu; Therrien, Bruno; Chérioux, Frédéric; Süss-Fink, Georg

    2006-01-01

    The single-crystal X-ray structure analyses of [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-O)][BF4]2 ([1][BF4]2), [HRu3(C6H6)(C6Me6)2(μ3-SC6H4Me)(μ2-S)][PF6]2 ([2][PF6]2) and [H2Ru3(1,2,4,5-Me4C6H2)3(μ2-S)(Cl)]PF6([3][PF6]) are presented. The structures show the sulfur ligands to act as bridges between ruthenium atoms. In [1][BF4]2 and [2][PF6]2 the metallic core adopts a nido framework. However, in [3][PF6] the absence of a μ3-SR ligand combined with the presence of one terminal chloro unit gives ris...

  8. 水/离子液体[BMIM]PF6两相体系中全细胞催化生成单葡萄糖醛酸基甘草次酸%Biosynthesis of glycyrrhetic acid 3-O-mono-β-D-glucuronide by whole cell in ionic liquid/water biphasic system

    Institute of Scientific and Technical Information of China (English)

    陈金燕; 邹树平; 何冬梅; 杨晓刚; 李春

    2011-01-01

    研究了水/离子液体两相体系中重组毕赤酵母Pichia pastoris GS115(r-PGUS-P)全细胞转化甘草酸(GL)生成单葡萄糖醛酸基甘草次酸(GAMG)的反应.确定最适反应体系为离子液体[BMIM] PF6/水(2∶8,体积比),最适缓冲液pH、反应温度、底物浓度和细胞加入量分别为5.4、45℃、6.O mmol·L-1和8.0g·L-1.在此条件下反应58 h,产物GAMG得率和化学键选择性分别为69.6%和67.2%,与纯水相反应体系相比,分别提高了12.4%和12.61%.离子液体循环使用7次后,回收利用率为93.47%.产物GAMG和副产物甘草次酸(GA)在此两相体系中得到有效分离,为后续产物分离带来便利.%Glycyrrhizin (GL), the biologically active compounds of liquorice, can be hydrolysed to glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG) by whole cells containing β-D-glucuronidase. GAMG is widely used in the pharmaceutical and food industries due to its stronger physiological functions, higher biological activity, more favorable sweetness, and lower caloric value as compared with GL. The recombinant Pichia pastoris (r-PGUS-P) designated in this work expressing β-D-glucuronidase, was used as a whole-cell biocatalyst catalyzing GL to GAMG in non-aqueous solvents systems. The results showed that r-PGUS-P gave the highest yield of GAMG in l-butyl-3-methylimidazolium hexafluorophosphate ( [BMIM] PF6 )/water (2 ∶ 8, vol) biphasic system. The optimal conditions of this reaction were determined as follows; optimum pH, substrate concentration, temperature and cell content were 5. 4, 6. 0 mmol · L-1, 45°C, and 8. 0 g · L-1, respectively. Under these optimized conditions, 69.6% yield of GAMG and 67. 2% of the chemical bond selectivity was achieved after 58 h reaction time, increase by 12. 4% and 12. 61%, respectively against aqueous phase. Simultaneously, the ionic liquid [BMIM]PF6 also remained at higher recovery percentage of about 93.47% during repeated use for 7 reaction cycles. Especially

  9. Study of reactivity of p-cymene ruthenium(II) dimer towards diphenyl-2-pyridylphosphine: Synthesis, characterization and molecular structures of [(6--cymene)RuCl2(PPh2Py)] and [(6--cymene)RuCl(PPh2Py)]BF4

    Indian Academy of Sciences (India)

    R Lalrempuia; Patrick J Carroll; Mohan Rao Kollipara

    2004-01-01

    The reaction of [{(6--cymene)Ru(-Cl)}2Cl2] with functionalized phosphine viz, diphenyl-2-pyridylphosphine yielded complexes of the type: (a) P-bonded complex [(6--cymene)RuCl2(PPh2Py)] (1), (b) P-, N-chelated complex [(6--cymene)RuCl-(PPh2Py)]BF4 (2) and [RuCl2(PPh2Py)2] (3) resulting from the displacement of the -cymene ligand. These complexes were characterized by 1H NMR, 31P NMR and analytical data. The structures of complexes 1 and 2 have been confirmed by single crystal X-ray diffraction study. Complex 1 crystallised in triclinic space group $\\bar{1}$ with = 10.9403 (3) Å, = 13.3108 (3) Å, = 10.5394 (10) Å, = 88.943 (2)°, = 117.193 (2)°, = 113.1680 (10)°, = 2 and = 1230.39 (5) Å3. The complex 2 crystallises in monoclinic space group 21 with = 9.1738 (4) Å, =14.0650 (6) s, = 10.7453 (5) Å, = 106.809 (1)°, = 2 and = 1327.22 (10) Å3.

  10. 离子液体[Bmim]PF6萃取-火焰原子吸收法测定水中痕量镉%Determination of Trace Cadmium in Water by Flame Atomic Absorption Spectrometry/with Ionic Liquid Extraction

    Institute of Scientific and Technical Information of China (English)

    王良; 李清; 闫永胜; 崔运成

    2011-01-01

    A novel method for the separation and determination of trace cadmium in environmental water sample by flame atomic absorption spectrometry (FAAS) with ionic liquid extraction was proposed. When the acidity of the solvent was pH 8, ionic liquid 1-butyl-3-methylimi dazolium hexafluorophosphate ([Bmim]PF6) was used as extractant, dithizone as the chelant, the sample was extracted for 3 min and determined by FAAS. The research result indicated that under optimum conditions, there was favorable linearity relation between 0. 15 and 58. 2 μg/L, detection limit (3δ) was 0. 095 ng/L (n=11). The recovery of this method was in the range of 90. 0% -108. 0% . The relative standard deviation is less than 5. 8% for the analysis of practical sample.%1 引言化学工业排放的废水含有大量金属镉,对环境产生严重危害,因而环境水样中痕量镉的准确测定具有重要意义.目前,常用原子吸收光谱法[1]测定痕量的镉,但由于环境水样中镉的含量低且样品复杂,为了提高分析方法的灵敏度和选择性,样品的预分离与富集至关重要.液-液萃取是一种常用的预分离与富集方法,但常用有机溶剂作萃取剂,易带来二次污染.离子液体是一种无毒、无污染、不挥发的"绿色溶剂"[2],具有安全、高效、环保等优点[3],已萃取分离了多种金属离子[4-5].本实验以双硫腙(H2Dz)为螯合剂,以离子液体1-丁基-3-甲基咪唑六氟磷酸盐( [Bmim]PF6)为萃取剂.用火焰原子吸收光谱法(FAAS)测定了离子液体相中的Cd,建立了痕量Cd的分离与分析方法,并应用于环境水样的分析.

  11. 水/[ NH2 ebim][ PF6]/Triton X-100/正丁醇/环己烷微乳液体系的制备%Preparation of microemulsion system based on[ NH2 ebim] [ BF6 ]/H2 O/TritonX-100/n-butonal/cyclohexane

    Institute of Scientific and Technical Information of China (English)

    刘红晶; 焦阳; 潘阳; 李冬

    2016-01-01

    Microemulsion with self-made task-specific ionic liquid[ NH2 ebim] [ BF6 ] ,[ NH2 ebim] [ BF6 ]/H2 O/TritonX-100/n-bu-tonal/cyclohexane microemulsion has been prepared. Microemulsion types have been determined by the analysis of electrical con-ductivity and the dynamic light scattering technique,and microemulsion region is divided into O/( S+W) and O/W microemulsion. The ternary phase diagrams has been drawn according to the experimental results. The aggregation behavior of water in the microe-mulsion system was studied by dissipative particle dynamics(DPD). The results of simulation are agree with those of experiment. The effects of the microemulsion region on the proportion of Triton X-100 and n-butonal were investigated. Experimental results show that the region of microemulsion increases with the increase of the proportion of Triton X-100 and n-butonal.%采用自制的功能离子液体1-(胺乙基)-3-丁基咪唑六氟磷酸盐([NH2ebim][PF6]),制备了水/[ NH2 ebim][ PF6]/Triton X-100/正丁醇/环己烷微乳液体系,通过动态光散射技术测定微乳液的粒径分布和分散相浓度,通过电导率仪测定体系电导率的变化,由这两种分析方法确定微乳液类型,微乳液类型被分为表面活性剂与水的互溶相包油型(O/S+W)和水包油型(O/W),并绘制出拟三元相图;通过耗散动力学(DPD)模拟不同水含量时微乳液体系中的聚集行为,模拟结果呈现出的微乳液类型与实验测定分析结果一致,证明了相图绘制的正确性;文中还考察了Triton X-100与正丁醇的比例对微乳液区域的影响,实验结果表明,随着Triton X-100与正丁醇的比例增加微乳液区域增大。

  12. 镍-多吡啶配合物[Ni(dmbpy)3](H2O)(ClO4)2的合成、晶体结构及与DNA相互作用研究%Synthesis, crystal structure and DNA-binding studies of a new polypyridyl nickel complex [Ni (dmbpy) 3] (H2O) (ClO4) 2

    Institute of Scientific and Technical Information of China (English)

    张万举; 王芳; 杨水彬

    2013-01-01

    A new polypyridyl nickel complex [Ni(dmbpy)3] (H2 O) (ClO4)2 (dmbpy=4,4′-dimethyl-2,2′-bipyridine) has been synthesized and characterized by single-crystal Xray diffraction method.It crystallizes in the triclinic system,space group P-1,with a =11.192(13) (A),b=14.444(18) (A),c=14.468(18) (A),α=84.86(2)°,β=76.691(19)°,γ=68.24(2)°,V=2114(4) (A)3 and Z=2.The molecular structure of the complex consists of a mononuclear nickel(Ⅱ) complex cation,two perchlorate anions and one water molecule.Each of the three dmbpy molecules chelates to the nickel(Ⅱ) atom in the usual bidentate mode and the nickel(Ⅱ) atom is six-coordinated in a distorted octahedral geometry.The binding studies of the complex with calf thymus DNA (CT DNA) have been explored by electronic absorption titration and fluorescence quenching experiments.The experimental results suggest that the complex bind to CT-DNA through two models:electrostatic and intercalatively binding.%合成了一个镍—多吡啶配合物[Ni(dmbpy)3](H2O)(ClO4)2(dmbpy=4,4′-二甲基2,2′-联吡啶),并通过室温挥发法培养了该配合物的单晶.单晶X-衍射结果表明,该配合物属三斜晶系,P-1空间群,主要晶体学参数为:a=11.192(13)(A),b=14.444(18)(A),c=14.468(18)(A),α=84.86(2)°,β=76.691(19)°,y=68.24(2)°,V=2114(4)(A)3,Z=2.配合物分子由1个单核镍阳离子单元[Ni(dmbpy)3]2+、2个高氯酸根阴离子和1个水分子组成,配合物中镍原子的配位环境为六配位的八面体构型,3个dmbpy分子以双齿形式和1个镍原子配位.通过紫外光谱和荧光光谱研究了该配合物与小牛胸腺DNA(CT-DNA)的相互作用,结果表明该配合物与CT-DNA之间存在静电和插入两种作用模式.

  13. Oxidative degradation of the organometallic iron(II) complex [Fe{bis[3-(pyridin-2-yl)-1H-imidazol-1-yl]methane}(MeCN)(PMe3)](PF6)2: structure of the ligand decomposition product trapped via coordination to iron(II).

    Science.gov (United States)

    Haslinger, Stefan; Pöthig, Alexander; Cokoja, Mirza; Kühn, Fritz E

    2015-12-01

    Iron is of interest as a catalyst because of its established use in the Haber-Bosch process and because of its high abundance and low toxicity. Nitrogen-heterocyclic carbenes (NHC) are important ligands in homogeneous catalysis and iron-NHC complexes have attracted increasing attention in recent years but still face problems in terms of stability under oxidative conditions. The structure of the iron(II) complex [1,1'-bis(pyridin-2-yl)-2,2-bi(1H-imidazole)-κN(3)][3,3'-bis(pyridin-2-yl-κN)-1,1'-methanediylbi(1H-imidazol-2-yl-κC(2))](trimethylphosphane-κP)iron(II) bis(hexafluoridophosphate), [Fe(C17H14N6)(C16H12N6)(C3H9P)](PF6)2, features coordination by an organic decomposition product of a tetradentate NHC ligand in an axial position. The decomposition product, a C-C-coupled biimidazole, is trapped by coordination to still-intact iron(II) complexes. Insights into the structural features of the organic decomposition products might help to improve the stability of oxidation catalysts under harsh conditions.

  14. Theoretical Study on Ionic Liquid Based on 1-Ethyl-3-Methyl- Imidazolium Cation and Hexafluorophosphate or Tetrafluoroborate

    Institute of Scientific and Technical Information of China (English)

    Renqing Lü; Zuogang Cao; Guoping Shen

    2007-01-01

    The Hartree-Fock and DFT/B3LYP methods have been employed to investigate the electronic structures of l-ethyl-3-methyl-imidazolium cation (EMIM+), BF-4 , PF-6, EMIM+-BF-4, and EMIM+-PF6-using the Gaussian-94 soft-package at 6-31+G(d,p) basis set level for hydrogen, carbon, nitrogen, boron, phosphorus, and fluorine atoms. Comparison of the electronic structures of the lowest energy of EMIM+-BF4- and EMIM+-PF6- pairs, and single EMIM+, BF-4 and PF-6 showed that the optimized EMIM+-BF-4 and EMIM+-PF-6 pair conformers were BF-4 and PF-6 outside the 5-ring plane between the ethyl group and the methyl group. The cohesion of C-H…F hydrogen bond between cation and anion is reinforced by charge assistance. The interaction energy between EMIM+ and PF-6 is 328.8 kJ/mol at the B3LYP level and 326.6 kj/mol at the Hartree-Fock level, whereas that between EMIM+ and BFJ is 353.5 kj/mol at the B3LYP level and 350.5 kj/mol at the Hartree-Fock level. The low energy interactions caused by bulky asymmetric EMIM+, and charge dispersion of cation and anion give rise to the low melting point of ionic liquid EMIM+-BF-4 and EMIM+-PF-6. The two hydrogen bonding models of single hydrogen bond formation, and the hydrogen transfer between C2 in EMIM+ and F in BF-4 or PF-6 were principally depicted.

  15. Direct Electrochemistry of a GCE Modified with HRP/Gel-MWCNTs in Ionic Liquid [BMIM] BF4%基于明胶-碳纳米管的辣根过氧化物酶修饰电极在离子液体中的直接电化学

    Institute of Scientific and Technical Information of China (English)

    姚慧; 王燕; 董元; 孙迪; 张严化

    2012-01-01

    制备了明胶(Gel)-多壁碳纳米管(MWCNTs)纳米复合物,将其修饰在玻碳电极表面,再吸附辣根过氧化物酶(HRP),制得明胶-多壁碳纳米管-辣根过氧化物酶修饰电极(Gel-MWCNTs-HRP/GCE).该修饰电极在PBS中的循环伏安图上出现了一对峰形良好、几乎对称的氧化还原峰,式量电位为-0.356 V(vs.SCE),表明包埋在Gel-MWCNTs中的HRP与电极之间发生了直接电子传递.当扫速在20 ~ 180 mV/s时,氧化峰电流(Ipa)与还原峰电流(Ipc)均与扫速成正比,表明电极过程是受电子传递速率控制的表面传质过程.运用循环伏安法研究了修饰电极的电化学特性,探讨了工作电位、pH值、干扰物质等对修饰电极的影响.实验结果表明,HRP在修饰电极表面能有效和稳定地进行直接电子转移,并保持了其对过氧化氢(H2O2)的生物催化活性.进一步研究发现,在含有亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸([BMIM]BF4)的溶液中,修饰电极对H2O2显示出更灵敏的催化活性,其线性范围为2.0×10-7~0.13 mol/L,检出限(S/N =3)为2.3×10-8 mol/L.该电极具有灵敏度高、重现性及稳定性好、使用寿命较长等优点,同时还显示了较好的抗干扰能力.%A novel hydrogen peroxide biosensor was constructed based on horseradish peroxidase (HRP) immobilized onto glass carbon electrode (GCE) , which was modified with the nanocomposite of gelatin and multi-walled carbon nanotubes ( MWCNTs ). The electrochemistry and electrocatalysis of the modified biosensor were investigated. A pair of well-defined and nearly symmetrical redox peaks with a formal potential of -0.356 Y(vs. SCE) in PBS were observed, which attribute to the direct electron transfer between the entrapped HRP and the electrode. The redox peak current was proportional to scan rate in the range of 20 -180 mV/s, indicating that the process was affected by e-lectronic transfer electrode rate control surface of mass transfer process

  16. 二苯并噻吩及其氧化物与离子液体相互作用的理论研究%Theoretical study on the interactions between dibenzothiophene/dibenzothiophene sulfone and ionic liquids

    Institute of Scientific and Technical Information of China (English)

    吕仁庆; 林进; 曲占庆

    2012-01-01

    采用密度泛函理论方法比较了DBT/DBTO2和[BMIM]+[PF6]-/[BMIM]+[BF4]-的相互作用.对最稳定的[BMIM]+[PF6]-、[BMIM]+[PF6--DBT、[BMIM]+[PF6]-DBTO2、[BMIM]+[BF4]-、[BMIM]+ [BF4]--DBT、[BMIM]+[BF4]--DBTO2进行了NBO和AIM分析.结果表明,DBT和[BMIM]+[PF6]/[BMIM]+[BF4]-中的咪唑环彼此相互平行,NBO和AIM分析表明它们之间发生了π-π相互作用.H1’和H9’形成的F…H氢键有利于π-π堆积作用的形成.DBTO2倾向于趋近C2-H2和甲基基团形成O…H相互作用;DBTO2优先吸附在[BMIM]+[PF6]-/[BMIM]+[BF4]-.在模拟油中,[BMIM]+[PF6]-和[BMIM]+[BF4]-离子液体对DBTO2的萃取能力大于DBT,其原因是可能是DBTO2具有较大的极性和O…H与F…H的氢键作用.%The interactions between sulfur-containing compounds of dibenzothiophene (DBT) and dibenzothiophene sulfone (DBTO2) and ionic liquids of 1-butyl-3-methylimidazolium hexafiuoropnospnate ([BMIM] + [PF6]-) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] + [BF4]-) were comparatively studied by using density functional theory.The most stable structures of [BMIM]+ [PF6]-,[BMIM]+ [PF6]--DBT,[BMIM]+ [PF6]--DBTO2,[BMIM]+ [BF4]-,[BMIM] + [BF4]--DBT,and [BMIM] + [BF4]--DBTO2 systems were obtained by natural bond orbitals (NBO) and atoms in molecules (AIM) anaiyses.The results indicated that DBT and [BMIM] rings of [BMIM] + [PF6]-/[BMIM] + [BF4]-are parallel to each other.There is a strong π-π interaction between them in terms of NBO and AIM analyses.The H1' and H9' involved F…H hydrogen bonding interactions may favor the formation of π-π stacking interactions.The DBTO2 preferentially locates near the C2-H2 and methyl group of [BMIM] + to form O…H interactions.The predicted geometries and interaction energies imply the preferential adsorption of DBTO2 on [BMIM] + [PF6]-/[BMIM] + [BF4]-.The [BMIM] + [PF6] /[BF4]-have better extracting ability to remove DBTO2 than DBT,possibly due to the larger polarity of DBTO2 and stronger interactions

  17. Experimentally determining the exchange parameters of quasi-two-dimensional Heisenberg magnets

    International Nuclear Information System (INIS)

    Though long-range magnetic order cannot occur at temperatures T>0 in a perfect two-dimensional (2D) Heisenberg magnet, real quasi-2D materials will invariably possess nonzero inter-plane coupling Jperpendicular driving the system to order at elevated temperatures. This process can be studied using quantum Monte Carlo calculations. However, it is difficult to test the results of these calculations experimentally since for highly anisotropic materials in which the in-plane coupling is comparable with attainable magnetic fields Jperpendicular is necessarily very small and inaccessible directly. In addition, because of the large anisotropy, the Neel temperatures are low and difficult to determine from thermodynamic measurements. Here, we present an elegant method of assessing the calculations via two independent experimental probes: pulsed-field magnetization in fields of up to 85 T, and muon-spin rotation. We successfully demonstrate the application of this method for nine metal-organic Cu-based quasi-2D magnets with pyrazine (pyz) bridges. Our results suggest the superexchange efficiency of the [Cu(HF2)(pyz)2]X family of compounds (where X can be ClO4, BF4, PF6, SbF6 and AsF6) might be controlled by the tilting of the pyz molecule with respect to the 2D planes

  18. 烷氧基和酚氧基取代的茂铁盐阳离子光引发剂的合成和表征%Synthesis and Characterization of Alkoxy and Phenoxy-substituted Ferrocenium Salt Cationic Photoinitiators

    Institute of Scientific and Technical Information of China (English)

    王涛; 万平玉; 马丽君

    2006-01-01

    Alkyl-substituted ferrocenium salts have limited solubility in epoxy oligomers and produce poisonous arene by photolysis. Herein, the synthesis and photoactivity of several alkoxy-substituted ferrocenium salts as long-wavelength UV light photoinitiators have been reported. [Cyclopendadien-Fe-anisole]PF6, [Cyclopendadien-Fe-anisole]BF4, [Cyclopendadien-Fe-diphenylether]PF6, [Cyclopendadien-Fe-diphenylether]BF4. and [Cyclopendadien-Fe-diethoxybenzene] PF6 for polymerization of epoxy resin were prepared through the ligand exchange reaction between one ring of ferrocene and aromatic ether. They all display good solubility and photoinitiating activities in epoxy resins.

  19. EFFECT OF WATER ON THE CONDUCTIVITY OF PPQ (ClO4) COMPLEX

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chi; LU Fengcai

    1993-01-01

    The preparation of conducting PPQ film was first reported in the previous paper[1]. It is very interesting that this film is highly sensitive to moisture in air. The hydration and dehydration of the film are accompanied by change not only in color but also in conductivity and UV-visible spectrum. The conducting PPQ is reduced to PPQ and loses its conductivity after being soaked in water.

  20. Solid-state materials for anion sensing in aqueous solution: highly selective colorimetric and luminescence-based detection of perchlorate using a platinum(II) salt.

    Science.gov (United States)

    Taylor, Stephen D; Howard, Whitney; Kaval, Necati; Hart, Robert; Krause, Jeanette A; Connick, William B

    2010-02-21

    The PF(6)(-) salt of a platinum(II) complex changes from yellow to red and becomes intensely luminescent upon exposure to aqueous ClO(4)(-). The response is remarkably selective. Spectroscopic changes are consistent with anion exchange resulting in shortening of the intramolecular PtPt distances between the square planar cations.

  1. Synthesis and properties of trimethyl-TSF containing alloys of the TMTSF2 family

    DEFF Research Database (Denmark)

    Johannsen, Ib; Bechgaard, Klaus; Jacobsen, C. S.;

    1985-01-01

    Cation-radical salts of the general formula (TriMTSFzTMTSF1-z)2 (X=PF6, ClO4, z ranging from 0 to 0.3) were isostructural. The incorporation of TriMTSF resulted only in minor changes in the transport properties, but the superconducting ground state was completely suppressed...

  2. Electroanalytical determination of trace chloride in room-temperature ionic liquids.

    Science.gov (United States)

    Villagrán, Constanza; Banks, Craig E; Hardacre, Christopher; Compton, Richard G

    2004-04-01

    The electroanalytical quantification of chloride in [C4mim][BF4], [C4mim][NTf2], and [C4mim][PF6] ionic liquids has been explored using linear sweep and square wave voltammetry. Cathodic stripping voltammetry at a silver disk electrode is found to be the most sensitive. The methodology is based on first holding the potential of the electrode at +2.0 V (vs Ag wire), to accumulate silver chloride at the electrode. On applying a cathodic scan, a stripping wave is observed corresponding to the reduction of the silver chloride. This stripping protocol was found to detect ppb levels of chloride in [C4mim][BF4], [C4mim][NTf2], and [C4mim][PF6]. Although other methods for chloride have been reported for [BF4](-)- and [PF6](-)-based ionic liquids, no methods have been reported for [NTf2](-) ionic liquids.

  3. Photo-induced spin transition of Iron(III) compounds with pi-pi intermolecular interactions.

    Science.gov (United States)

    Hayami, Shinya; Hiki, Kenji; Kawahara, Takayoshi; Maeda, Yonezo; Urakami, Daisuke; Inoue, Katsuya; Ohama, Mitsuo; Kawata, Satoshi; Sato, Osamu

    2009-01-01

    Iron(III) spin-crossover compounds [Fe(pap)(2)]ClO(4) (1), [Fe(pap)(2)]BF(4) (2), [Fe(pap)(2)]PF(6) (3), [Fe(qsal)(2)]NCS (4), and [Fe(qsal)(2)]NCSe (5) (Hpap=2-(2-pyridylmethyleneamino)phenol and Hqsal=2-[(8-quinolinylimino)methyl]phenol) were prepared and their spin-transition properties investigated by magnetic susceptibility and Mössbauer spectroscopy measurements. The iron(III) compounds exhibited spin transition with thermal hysteresis. Single crystals of the iron(III) compounds were obtained as suitable solvent adducts for X-ray analysis, and structures in high-spin (HS) and low-spin (LS) states were revealed. Light-induced excited-spin-state trapping (LIESST) effects of the iron(III) compounds were induced by light irradiation at 532 nm for 1-3 and at 800 nm for 4 and 5. The activation energy E(a) and the low-temperature tunneling rate k(HL)(T-->0) of iron(III) LIESST compound 1 were estimated to be 1079 cm(-1) and 2.4x10(-8) s(-1), respectively, by HS-->LS relaxation experiments. The Huang-Rhys factor S of 1 was also estimated to be 50, which was similar to that expected for iron(II) complexes. It is thought that the slow relaxation in iron(III) systems is achieved by the large structural distortion between HS and LS states. Introduction of strong intermolecular interactions, such as pi-pi stacking, can also play an important role in the relaxation behavior, because it can enhance the structural distortion of the LIESST complex. PMID:19191246

  4. Spin-State Versatility in a Series of Fe4 [2 × 2] Grid Complexes: Effects of Counteranions, Lattice Solvent, and Intramolecular Cooperativity.

    Science.gov (United States)

    Steinert, Markus; Schneider, Benjamin; Dechert, Sebastian; Demeshko, Serhiy; Meyer, Franc

    2016-03-01

    The new compartmental proligand 4-bromo-3,5-bis{6-(2,2'-bipyridyl)}pyrazole (HL(Br)) was synthesized and shown to form robust [2 × 2] grid complexes [Fe(II)4L(Br)4]X4 with various counteranions (X(-) = PF6(-), ClO4(-), BF4(-), Br(-)). The grid [Fe(II)4L(Br)4](4+) is stable in solution and features two high-spin (HS) and two low-spin (LS) ferrous ions in frozen MeCN, and its redox properties have been studied. Six all-ferrous compounds [Fe4L(Br)4]X4 with different counteranions and different lattice solvent (1a-f) were structurally characterized by X-ray diffraction, and their magnetic properties were investigated by Mössbauer spectroscopy and SQUID magnetometry. Variations in spin-state for the crystalline material range from the [4HS] via the [3HS-1LS] to the [2HS-2LS] forms, with some grids showing thermal spin crossover (SCO). The series of [Fe(II)4L(Br)4](4+) compounds allowed us to establish experimentally well-grounded correlations between structural distortion of the {FeN6} coordination polyhedra, quantified by using continuous shape measures, and the grid's spin-state pattern. These correlations evidenced pronounced cooperativity for the multistep SCO transitions within the grid, imparted by the strain effects of the rigid bridging ligands, and a high stability of the dimixed-spin configuration trans-[2HS-2LS] that has identical sites at opposite corners of the grid. The results are in good agreement with recent quantum chemical calculations for such molecular [2 × 2] grids featuring strongly elastically coupled vertices. PMID:26881723

  5. Unexpected Spin-Crossover and a Low-Pressure Phase Change in an Iron(II)/Dipyrazolylpyridine Complex Exhibiting a High-Spin Jahn- Teller Distortion.

    Science.gov (United States)

    Kershaw Cook, Laurence J; Thorp-Greenwood, Flora L; Comyn, Tim P; Cespedes, Oscar; Chastanet, Guillaume; Halcrow, Malcolm A

    2015-07-01

    The synthesis of 4-methyl-2,6-di(pyrazol-1-yl)pyridine (L) and four salts of [FeL2]X2 (X– = BF(4)(–), 1; X– = ClO(4)(–), 2; X– = PF(6)(–), 3; X– = CF3SO(3)(–), 4) are reported. Powder samples of 1 and 2 both exhibit abrupt, hysteretic spin-state transitions on cooling, with T(1/2)↓ = 204 and T(1/2)↑ = 209 K (1), and T(1/2)↓ = 175 and T(1/2)↑ = 193 K (2). The 18 K thermal hysteresis loop for 2 is unusually wide for a complex of this type. Single crystal structures of 2 show it to exhibit a Jahn–Teller-distorted six-coordinate geometry in its high-spin state, which would normally inhibit spin-crossover. Bulk samples of 1 and 2 are isostructural by X-ray powder diffraction, and undergo a crystallographic phase change during their spin-transitions. At temperatures below T(1/2), exposing both compounds to 10(–5) Torr pressure inside the powder diffractometer causes a reversible transformation back to the high-temperature crystal phase. Consideration of thermodynamic data implies this cannot be accompanied by a low → high spin-state change, however. Both compounds also exhibit the LIESST effect, with 2 exhibiting an unusually high T(LIESST) of 112 K. The salts 3 and 4 are respectively high-spin and low-spin between 3 and 300 K, with crystalline 3 exhibiting a more pronounced version of the same Jahn–Teller distortion. PMID:26351707

  6. Electrochemical Reduction of 2-Nitroanisole in Ionic Liquid BMIm-BF4: Synthesis of 2-Anisidine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new electrochemical synthesis of 2-anisidine from 2-nitroanisole has been developed in room-temperature ionic liquid (RTIL), which was carded out under mild and safe conditions, where the volatile, toxic solvents, catalysts, as well as any additional supporting electrolyte were avoided. The maximal yield of 2-anisidine reached 51.3% on Cu-graphite couple electrodes under potentiostatic electrolysis at -1.0 V (vs. SCE) until 6 F·mol-1 of charge was passed at 50℃, which offers a new and clean route to synthesis of 2-anisidine. The reduction behavior of 2-nitroanisole was studied in RTIL by cycle voltammertry. The RT1L could be recycled.

  7. Designing New Electrolytes for Lithium Ion Batteries Using Superhalogen Anions

    CERN Document Server

    Srivastava, Ambrish Kumar

    2016-01-01

    The electrolytes used in Lithium Ion Batteries (LIBs) such as LiBF4, LiPF6 etc. are Li-salts of some complex anions, BF4-, PF6- etc. The investigation shows that the vertical detachment energy (VDE) of these anions exceeds to that of halogen, and therefore they behave as superhalogen anions. Consequently, it might be possible to design new electrolytic salts using other superhalogen anions. We have explored this possibility using Li-salts of various superhalogen anions such as BO2-, AlH4-, TiH5- and VH6- as well as hyperhalogen anions, BH4-y(BH4)y-(y = 1 to 4). Our density functional calculations show that Li-salts of these complex anions possess similar characteristics as those of electrolytic salts in LIBs. Note that they all are halogen free and hence, non-toxic and safer than LiBF4, LiPF6 etc. In particular, LiB4H13 and LiB5H16 are two potential candidates for electrolytic salt due to their smaller Li-dissociation energy ({\\Delta}E) than those of LiBF4, LiPF6 etc. We have also noticed that {\\Delta}E of Li...

  8. Synthesis, structure, and properties of azatriangulenium salts

    DEFF Research Database (Denmark)

    Laursen, B.W.; Krebs, Frederik C

    2001-01-01

    A general synthetic route to novel nitrogen-bridged heterocyclic carbenium ions of the acridinium and triangulenium type has been developed and investigated. The synthetic method is based on nucleophilic aromatic substitution (SNAr) on the tris(2,6-dimethoxyphenyl)carbenium ion (1) with primary a...... amines and, by virtue of its stepwise and irreversible nature, provides a powerful tool for the preparation of a wide variety of new heterocyclic carbenium salts. Several derivatives of the three new oxygen- and/or nitrogen-bridged triangulenium salts, azadioxa- (6), diazaoxa- (7......), and triazatriangulenium (4), have been synthesized and their physicochemical properties have been investigated. Crystal structures for compounds 2 b-PF6: 2d-PF6, 4b-BF4, 4c-BF4, 6e-BF4, and 8 are reported. The different packing modes found for the triazatriagulenium salts are discussed in relation to the electrostatic...

  9. Tuning the optical properties of 2-thienylpyridyl iridium complexes through carboranes and anions.

    Science.gov (United States)

    Zhu, Lin; Tang, Xiao; Yu, Qi; Lv, Wen; Yan, Hong; Zhao, Qiang; Huang, Wei

    2015-03-16

    2-Thienylpyridyl iridium(III) complexes containing an o-, m-, or p-carboranylvinyl-2,2'-bipyridine ligand and various counteranions (denoted o-PF6, m-BF4, m-PF6, m-SbF6, m-ClO4, m-OTf, m-NO3, m-BPh4, m-F, m-Cl, and p-PF6) were synthesized by using C-formyl carboranes as starting materials. The solid-state structures of o-PF6, m-PF6, m-ClO4, and m-BF4 showed that the cations form twisted cavities in which the anions are fixed by multiple hydrogen bonds. Anion-hydrogen interactions were investigated for nine m-carborane-based complexes with different counteranions. All carborane-based iridium(III) complexes show similar phosphorescence yields in solution but significantly different emission in the solid state. Anion-exchange titration and theoretical calculations revealed the relationships between structures and optical properties. The size of the anion and C-H⋅⋅⋅X anion-hydrogen bonds strongly influence the phosphorescence quantum yield in the solid state. In particular, the Ccar-H⋅⋅⋅X hydrogen bonds between the carboranyl unit and the anion play an important role in solid-state phosphorescence. Complex p-PF6 was successfully applied in phosphorescence-lifetime bioimaging owing to its low toxicity and near-infrared emission. PMID:25663604

  10. SEPARATION OF AROMATIC HYDROCARBONS OR OLEFINS FROM PARAFFINS USING NEW IONIC LIQUIDS%新型离子液体用于芳烃、烯烃与烷烃分离的初步研究

    Institute of Scientific and Technical Information of China (English)

    朱吉钦; 陈健; 费维扬

    2004-01-01

    The separation of aromatic hydrocarbons or olefins from paraffins is very important in chemical industry. The volatile organic solvents used are usually harmful to environment and human health. As green solvents, room temperature ionic liquids are potential substitutes for the separation of hydrocarbon products. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes,alkylbenzenes and styrene, in 1-butyl-3-methyl imidazolium hexafluorophosphate ( [BMIM] [PF6]), 1-allyl-3-methylimidazolium tetrafluoroborate ( [AMIM] [BF4] ), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ( [MPMIM] [BF4]) and [MPMIM] [BF4]+AgBF4 were determined by gas-liquid chromatography. The measurements were carried out at different temperatures between 298.15 K and 318. 15 K. The separation effects of these ionic liquids for olefin/paraffin, alkanes/benzene and hexene isomers were discussed.

  11. Catalytic Epoxidation of a Technical Mixture of Methyl Oleate and Methyl Linoleate in Ionic Liquids Using MoO(O22•2QOH (QOH = 8-quinilinol as Catalyst and NaHCO3 as co-Catalyst

    Directory of Open Access Journals (Sweden)

    Chuan-Lei Fan

    2009-08-01

    Full Text Available The oxo-diperoxo molybdenum(VI complex MoO(O22•2QOH (QOH = 8-quinilinol was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs [bmim][BF4], [hydemim][BF4], and [bmim][PF6] were characterized by 1H-NMR and UV-Vis spectra. The epoxidation of a technical mixture of methyl oleate and methyl linoleate with H2O2, in [bmim][BF4], [hydemim][BF4] and [bmim][PF6], catalyzed by MoO(O22•2QOH (QOH = 8-quinilinol and with NaHCO3 as co-catalyst has been studied for the first time. It was found that high conversions of methyl oleate and methyl linoleate to their respective oxidation products, as well as the total selectivity of their oxidation products to oxirane in [hydemim][BF4] were obtained. Also, the IL phases containing the Mo(VI catalyst can be readily recycled by washing with diethyl ether and drying, and the Mo(VI catalyst can be reused at least five times.

  12. Syntheses, characterization and electrochemical and spectroscopic properties of ruthenium-iron complexes of 2,3,5,6-tetrakis(2-pyridyl)pyrazine and ferrocene-acetylide ligands.

    Science.gov (United States)

    Wen, Hui-Min; Wang, Jin-Yun; Zhang, Li-Yi; Shi, Lin-Xi; Chen, Zhong-Ning

    2016-06-28

    Heterodimetallic Ru-Fe complexes [(tppz)(PPh3)2RuL](ClO4) (L = C[triple bond, length as m-dash]CFc, [](ClO4); C[triple bond, length as m-dash]C-C6H4-C[triple bond, length as m-dash]CFc), [](ClO4); C[triple bond, length as m-dash]C-C6H4-C6H4-C[triple bond, length as m-dash]CFc, [](ClO4)) were synthesized by the reactions of [(tppz)(PPh3)2RuCl](ClO4) (tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine) with ferrocence-acetylide ligands and characterized by ESI-MS, and (1)H and (31)P NMR spectroscopies. The structure of [](PF6) was determined by X-ray crystallography. The electrochemical studies show that compounds [](ClO4)-[](ClO4) possess two widely separated anodic peaks, ascribable to one-electron oxidation of Fc and Ru(II), respectively. This assignment is further corroborated by the results of UV-vis-NIR, XPS, and theoretical calculation studies. Compound [](ClO4) exhibits significant RuFe metal-metal interactions across the Ru-C[triple bond, length as m-dash]C-Fc backbone. As revealed by electrochemical, spectroscopic and theoretical computational studies, one-electron oxidized species [](ClO4)2 is between the electronically delocalized and valence-trapped state and shows a typical Robin-Day class II mixed-valence behavior. PMID:27273611

  13. Charge-Transfer Excitations in the Model Superconductor HgBa$_2$CuO$_{\\bf 4+\\delta}$

    OpenAIRE

    L. Lu; Zhao, X.; Chabot-Couture, G.; Hancock, J. N.; Kaneko, N; Vajk, O. P.; Yu, G.; Grenier, S.; Kim, Y. J.; Casa, D.; Gog, T.; Greven, M.

    2005-01-01

    We report a Cu $K$-edge resonant inelastic x-ray scattering (RIXS) study of charge-transfer excitations in the 2-8 eV range in the structurally simple compound HgBa$_2$CuO$_{4+\\delta}$ at optimal doping ($T_{\\rm c} = 96.5 $ K). The spectra exhibit a significant dependence on the incident photon energy which we carefully utilize to resolve a multiplet of weakly-dispersive ($ < 0.5$ eV) electron-hole excitations, including a mode at 2 eV. The observation of this 2 eV excitation suggests the exi...

  14. Second virial coefficient of bmimBF4/triton X-100/ cyclohexane ionic liquid microemulsion as investigated by microcalorimetry.

    Science.gov (United States)

    Li, Na; Zhang, Shaohua; Zheng, Liqiang; Gao, Yan'an; Yu, Li

    2008-04-01

    The second virial coefficient of the ionic liquid (IL) microemulsion was obtained for the first time using microcalorimetry. The heat of dilution of the microemulsion solutions was measured by isothermal titration microcalorimetry (ITC), and the second virial coefficient was derived from the heat of dilution and the number density of the IL microemulsion solutions on the basis of a hard-sphere interaction potential assumption and as a function of the second-order polynomial. The validity of the second virial coefficient was confirmed by the percolation behavior of different ionic liquid microemulsion solutions of Triton X-100 in cyclohexane with or without added salts. The information obtained from the second virial coefficient shows that the interactions between ionic liquid microemulsion droplets are much stronger than those for traditional microemulsions, which may be attributed to the relatively larger size of the microemulsion droplets. PMID:18312017

  15. Solute recovery from ionic liquids: a conceptual design study for recovery of styrene monomer from [4-mebupy][BF4

    NARCIS (Netherlands)

    Jongmans, M.T.G.; Trampe, J.; Schuur, B.; Haan, de A.B.

    2013-01-01

    Extractive distillation using ionic liquids (ILs) is a promising technology to separate the close-boiling mixture ethylbenzene/styrene. A proper solvent regeneration is crucial to obtain a technical and economic feasible process. In this work, several regeneration technologies were studied to recove

  16. Assembly of Heterometallic Rigid-Rod Complexes and Coordination Oligomers from Gold(I) Metalloligands.

    Science.gov (United States)

    Cámara, Verónica; Barquero, Natalia; Bautista, Delia; Gil-Rubio, Juan; Vicente, José

    2015-07-01

    The reactions of TpylC6H4C≡CAuL (Tpyl = 2,2':6',2″-terpyridin-4'-yl; L = PPh3, CNXy; Xy = 2,6-dimethylphenyl) with MX2·nH2O (M = Fe, X = ClO4; M = Co, X = BF4; M = Zn, X = TfO, ClO4) in a 2:1 molar ratio give complexes [M(TpylC6H4C≡CAuL)2]X2. Similarly, the reactions of PPN[(TpylC6H4C≡C)2Au] (PPN = (Ph3P)2N) with an equimolar amount of MX2·nH2O give coordination oligomers [M{(TpylC6H4C≡C)2Au}]nXn (M = Fe, Zn, X = ClO4; M = Co, X = BF4). The complexes and oligomers have been isolated and characterized. The crystal structures of [Fe(TpylC6H4C≡CAuCNXy)2](ClO4)2 and [Co(TpylC6H4C≡CAuPPh3)2](BF4)2 have been determined by X-ray diffraction. The hydrodynamic sizes of complexes [M(TpylC6H4C≡CAuPPh3)2]X2 and coordination oligomers [M{(TpylC6H4C≡C)2Au}]nXn have been studied by NMR diffusion spectroscopy and dynamic light scattering measurements. PMID:26087239

  17. Identity of Passive Film Formed on Aluminum in Li-ion BatteryElectrolytes with LiPF6

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xueyuan; Devine, T.M.

    2006-09-01

    The passive film that forms on aluminum in 1:1 ethylene carbonate + ethylmethyl carbonate with 1.2M LiPF{sub 6} and 1:1 ethylene carbonate + dimethyl carbonate with 1.0M LiPF{sub 6} was investigated by a combination of electrochemical quartz crystal microbalance measurements (EQCM), electrochemical impedance spectroscopy (EIS), and x-ray photoelectron spectroscopy. During anodic polarization of aluminum a film of AlF{sub 3} forms on top of the air-formed oxide, creating a duplex, or two-layered film. The thickness of the AlF{sub 3} increases with the applied potential. Independent measurements of film thickness by EQCM and EIS indicate that at a potential of 5.5V vs. Li/Li{sup +}, the thickness of the AlF{sub 3} is approximately 1 nm.

  18. Use of Ionic Liquids in Recycle of Palladium Catalysts for Synthesis of Polyketone

    Institute of Scientific and Technical Information of China (English)

    TIAN Jing; GUO Jintang; ZHANG Xuemei; ZHANG Xin; XU Yongshen

    2008-01-01

    Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated.[Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2'-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.

  19. Solvation of the fluorine containing anions and their lithium salts in propylene carbonate and dimethoxyethane.

    Science.gov (United States)

    Chaban, Vitaly

    2015-07-01

    Electrolyte solutions based on the propylene carbonate (PC)-dimethoxyethane (DME) mixtures are of significant importance and urgency due to emergence of lithium-ion batteries. Solvation and coordination of the lithium cation in these systems have been recently attended in detail. However, analogous information concerning anions (tetrafluoroborate, hexafluorophosphate) is still missed. This work reports PM7-MD simulations (electronic-structure level of description) to include finite-temperature effects on the anion solvation regularities in the PC-DME mixture. The reported result evidences that the anions appear weakly solvated. This observation is linked to the absence of suitable coordination sites in the solvent molecules. In the concentrated electrolyte solutions, both BF4(-) and PF6(-) prefer to exist as neutral ion pairs (LiBF4, LiPF6). PMID:26067106

  20. Adsorption, Thermodynamic and Quantum Chemical Studies of 1-hexyl-3-methylimidazolium Based Ionic Liquids as Corrosion Inhibitors for Mild Steel in HCl

    Directory of Open Access Journals (Sweden)

    Motsie E. Mashuga

    2015-06-01

    Full Text Available The inhibition of mild steel corrosion in 1 M HCl solution by some ionic liquids (ILs namely, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate [HMIM][TfO], 1-hexyl-3-methylimidazolium tetrafluoroborate [HMIM][BF4], 1-hexyl-3-methylimidazolium hexafluorophosphate [HMIM][PF6], and 1-hexyl-3-methylimidazolium iodide [HMIM][I] was investigated using electrochemical measurements, spectroscopic analyses and quantum chemical calculations. All the ILs showed appreciably high inhibition efficiency. At 303 K, the results of electrochemical measurements indicated that the studied ILs are mixed-type inhibitors. The adsorption studies showed that all the four ILs adsorb spontaneously on steel surface with [HMIM][TfO], [HMIM][BF4] and [HMIM][I] obeying Langmuir adsorption isotherm, while [HMIM][PF6] conformed better with Temkin adsorption isotherm. Spectroscopic analyses suggested the formation of Fe/ILs complexes. Some quantum chemical parameters were calculated to corroborate experimental results.

  1. First Claisen Rearrangement Reaction in Ionic Liquids with Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    XU Li-Wen; LI Fu-Wei; XIA Chun-Gu

    2003-01-01

    @@ We have demonstrated the first use of the common ionic liquids, [1] bmimBr, bmimBF4 and bmimPF6 as an environmentally benign solvent for the simple Claisen rearrangement under microwave irradiation. In many cases, the re action was carried out in toxic solvents of high boiling point. [2] Here we reported the first example of Claisen rear rangement reaction in green solvents, ionic liquids, under microwave irradiation.

  2. Mechanistic insights into acetophenone transfer hydrogenation catalyzed by half-sandwich ruthenium(II) complexes containing 2-(diphenylphosphanyl)aniline - a combined experimental and theoretical study

    NARCIS (Netherlands)

    A. Bacchi; M. Balordi; R. Cammi; L. Elviri; C. Pelizzi; F. Picchioni; V. Verdolino; K. Goubitz; R. Peschar; P. Pelagatti

    2008-01-01

    Several new half-sandwich ruthenium(II) complexes containing 2-(diphenyphosphanyl)aniline (PNH2) of formula {Ru[(kappa P-2,N)PNH2](p-cymene)Cl}Y [Y = Cl (1a), PF6 (1b), BF4 (1c), BPh4 (1d), TfO (1e)] were synthesized and fully characterized both in solution (H-1 NMR and P-31{H-1) NMR spectroscopy) a

  3. Detailed magnetic study on the formato-bridged MOFs with anion-tunable magnetic properties

    Institute of Scientific and Technical Information of China (English)

    WANG XinYi; WANG ZheMing; GAO Song

    2012-01-01

    Detailed studies of the structures,magnetic properties and photodimerization of a series of formato-bridged MOFs with the general formula M2(HCOO)3(4,4'-bpe)3(H20)3(X)(4,4'-bpe =4,4'-bipyridylethylene,M =Mn(l-X-),X- =CIO-4,NO-3,BF-4,I-,Br-; M =Co(2-X-),X- =CIO-4,NO-3; M =Zn(3-X-),X- =NO-3)were reported.Careful magnetic measurements on an oriented single crystal of 1-ClO-4 determined the spin-flop magnetic phase diagram and some intrinsic parameters,such as the intralayer coupling J,the anisotropy field HA and the exchange field HE.Different anions can remarkably tune the magnetic properties of l-X-,especially the critical fields of the spin-flop transition.Compound 2-ClO-4 remained paramagnetic down to 2 K.

  4. One-dimensional Chain Topology in [Ag(C6H6NCl)2](ClO4),Generated through Weak Interaction between Molecules

    Institute of Scientific and Technical Information of China (English)

    孙道峰; 曹荣; 梁玉仓; 洪茂椿; 苏伟平

    2001-01-01

    The mononuclear complex [Ag(C6H6NC1)2](C1O4) has been prepared and structurally analyzed by single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group C2/c with unit cell parameters: a=15.5314(2), b=8.0247(8),c=15.3701 (2)A. β =118.832(2)°, V=1678.2(3)A3, Z=4, Mr=462.46, Dc=1.830Mg/m3, F(000)=912,μt (MoKa) = 1.694cm-1. The final R and wR are 0.0472 and 0.1272 for 1484 observed reflections with I≥3σ (Ⅰ). The Ag atom is coordinated by two nitrogen atoms of 4-chloromethyl-pyridine in a linear coordination geometry. Each molecule is further linked by the weak interaction between the C1 and Ag atoms to form a one-dimensional chain structure with Ag-C1 distance of 3.240(A).

  5. Thermochemical Properties of RE(Gly) 4Im( ClO4) 3· 2H2O(RE = La, Pr, Nd, Sm, Eu)

    Institute of Scientific and Technical Information of China (English)

    何水样; 刘向荣; 宋迪生; 胡荣祖

    2001-01-01

    The enthalpies of solution in water for five new light rare earth ternary complexes RE(Gly)4Im(ClO4)3@ 2H2O (gE =La, Pr, Nd, Sm, Eu; Gly-glycine; Im-imidazole) were measured by means of a Calvet microcalorimeter. The empirical formula of enthalpy of solution (Asol H), relative apparent molar enthalpy ( φLi ), relative partial molar enthalpy ( Li )and enthalpy of dilution (AdilH1,2) were drawn up by the data of entalpies of solution of these complexes. From three plots of the values of standard enthalpy of solution AsolHΘm, φLi,Li) versus the values of ionic radius (r) of the light rare earth elements, the grouping effect of lanthanide was observed, showing that the coordination bond between rare earth ion and ligand possesses a certain extent of the property of a covalent bond. The standard enthalpies of solution in water of similar complexes, Ce(Gly)4Im(ClO4)3@2H2O were estimated according to the plot of AsolHΘm, versus r.

  6. Reversible supra-channel effects: 3D kagome structure and catalysis via a molecular array of 1D coordination polymers.

    Science.gov (United States)

    Lee, Haeri; Noh, Tae Hwan; Jung, Ok-Sang

    2013-10-14

    Self-assembly of CuX2 (X(-) = ClO4(-) and BF4(-)) with 2,3-bis(nicotinoyloxy)naphthalene yields a 1D loop-chain skeleton. The loop-chains form an ensemble constituting a unique 3D kagome-type structure with both hexagonal and trigonal supra-channels. The unprecedented supra-channel effects on the catalytic oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylbenzoquinone were investigated.

  7. Conductivities of AlCl3/Ionic Liquid Systems and Their Application in Electrodeposition of Aluminium

    Institute of Scientific and Technical Information of China (English)

    岳贵宽; 吕兴梅; 朱艳丽; 王慧; 张香平; 张锁江

    2008-01-01

    Solubilities and conduetivities of anliydrons AlCl3 in six kinds of ionic liquids (ILs) were measured. Among the sixkinds of ILs [bmim]Cl, [bmim]Br, [bmim]BF4, [bmim]PF6, [emim][EtSO4] and [bmim][HSO4], anhydrous AlCl3 could bedissolved in the first five kinds but was hardly dissolved in [bmim][HSO4]. The results showed that the nominal solubilities ofAlCl3 in ILs increased in the order of [bmim][HSO4] < [bmim]PF6 < [emim][EtSO4] <[bmim]BF4<[bmim]Cl<[bmim]Br.Conduetivities of the AlCl3/ILs systems depended apparently on the nominal molar ratio of AlCl3 to ILs. The conduetivities ofAlCl3/[bmim]Cl, AlCl3/[bmim]Br and AlCl3/[bmim]PF6 systems had a similar tendency as a fimetion of the nominal molarratio, that is, as the molar ratio was increased, conductivities increased first and then decreased, with the maximumconductivity obtained at approximately 0.9:1, 1.0:1 and 0.5:1, respectively. Conduetivities of the AlCl3/[bmim]BF4 exhibited adentate change and decreased with the molar ratio of AlCl3 to [bmim]BF4 increasing in general. With the increasing of theanhydrous AlCl3 amount in [emim][EtSO4], conductivity of AlCl3/[emim][EtSO4] monotonically decreased. AlCl3/[bmim]Clsystem was chosen as the electrolyte for the electrodeposition of Al. Preliminary experimental results showed that dense,adherent and homogeneous Al coatings could be electrodeposited on stainless steel by means of constant potential techniqueand the surface coverage was quite satisfactory.

  8. Ionic liquids increase the catalytic efficiency of a lipase (Lip1) from an antarctic thermophilic bacterium.

    Science.gov (United States)

    Muñoz, Patricio A; Correa-Llantén, Daniela N; Blamey, Jenny M

    2015-01-01

    Lipases catalyze the hydrolysis and synthesis of triglycerides and their reactions are widely used in industry. The use of ionic liquids has been explored in order to improve their catalytic properties. However, the effect of these compounds on kinetic parameters of lipases has been poorly understood. A study of the kinetic parameters of Lip1, the most thermostable lipase from the supernatant of the strain ID17, a thermophilic bacterium isolated from Deception Island, Antarctica, and a member of the genus Geobacillus is presented. Kinetic parameters of Lip1 were modulated by the use of ionic liquids BmimPF6 and BmimBF4. The maximum reaction rate of Lip1 was improved in the presence of both salts. The highest effect was observed when BmimPF6 was added in the reaction mix, resulting in a higher hydrolytic activity and in a modulation of the catalytic efficiency of the enzyme. However, the catalytic efficiency did not change in the presence of BmimBF4. The increase of the reaction rates of Lip1 promoted by these ionic liquids could be related to possible changes in the Lip1 structure. This effect was measured by quenching of tryptophan fluorescence of the enzyme, when it was incubated with each liquid salt. In conclusion, the hydrolytic activity of Lip1 is modulated by the ionic liquids BmimBF4 and BmimPF6, improving the reaction rate and the catalytic efficiency of this enzyme when BmimPF6 was used. This effect is probably due to changes in the structure of Lip1 induced by the presence of these ionic liquids, stimulating its catalytic activity.

  9. Ionic liquids increase the catalytic efficiency of a lipase (Lip1) from an antarctic thermophilic bacterium.

    Science.gov (United States)

    Muñoz, Patricio A; Correa-Llantén, Daniela N; Blamey, Jenny M

    2015-01-01

    Lipases catalyze the hydrolysis and synthesis of triglycerides and their reactions are widely used in industry. The use of ionic liquids has been explored in order to improve their catalytic properties. However, the effect of these compounds on kinetic parameters of lipases has been poorly understood. A study of the kinetic parameters of Lip1, the most thermostable lipase from the supernatant of the strain ID17, a thermophilic bacterium isolated from Deception Island, Antarctica, and a member of the genus Geobacillus is presented. Kinetic parameters of Lip1 were modulated by the use of ionic liquids BmimPF6 and BmimBF4. The maximum reaction rate of Lip1 was improved in the presence of both salts. The highest effect was observed when BmimPF6 was added in the reaction mix, resulting in a higher hydrolytic activity and in a modulation of the catalytic efficiency of the enzyme. However, the catalytic efficiency did not change in the presence of BmimBF4. The increase of the reaction rates of Lip1 promoted by these ionic liquids could be related to possible changes in the Lip1 structure. This effect was measured by quenching of tryptophan fluorescence of the enzyme, when it was incubated with each liquid salt. In conclusion, the hydrolytic activity of Lip1 is modulated by the ionic liquids BmimBF4 and BmimPF6, improving the reaction rate and the catalytic efficiency of this enzyme when BmimPF6 was used. This effect is probably due to changes in the structure of Lip1 induced by the presence of these ionic liquids, stimulating its catalytic activity. PMID:25425150

  10. On anodic stability and decomposition mechanism of sulfolane in high-voltage lithium ion battery

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Influence of lithium salts on the anodic stability of sulfolane has been investigated. • Oxidation decomposition mechanisms of LiPF6/Sulfolane electrolyte have been well understood by theoretical and experimental methods. • Decomposition products of the electrolyte can be found on the electrode surface and in the interfacial electrolyte. - Abstract: In this work, we investigated the anodic stability and decomposition mechanism of sulfolane (SL). The anodic stability of SL-based electrolyte with different lithium salts on Pt and LiNi0.5Mn1.5O4 electrodes was found to decrease as follows: LiPF6/SL > LiBF4/SL > LiClO4/SL. The oxidation potential of 1M LiPF6/SL electrolyte on both Pt and electrodes is about 5.0V vs Li/Li+. The presence of PF6- and another SL solvent dramatically alters the decomposition mechanism of SL. Oxidation decomposition of SL-SL cluster is the most favorable reaction in LiPF6/SL electrolyte. The dimer products with S-O-R group were detected by IR spectra on the charged LiNi0.5Mn1.5O4 electrode surface and in the electrolyte near the electrode surface, and were found to increase the interfacial reaction resistance of the LiNi0.5Mn1.5O4 electrode

  11. Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in lithium bis(fluorosulfonyl)imide electrolytes

    Science.gov (United States)

    Park, Kisung; Yu, Sunghun; Lee, Chulhaeng; Lee, Hochun

    2015-11-01

    Lithium bis(fluorosulfonyl)imide (LiFSI) is a promising salt that can possibly overcome the limitations of lithium hexafluorophosphate (LiPF6) in current Li-ion batteries (LIBs). Aluminum (Al) corrosion issue, however, is a major bottleneck for the wide use of LiFSI. This study investigates lithium borate salts as Al corrosion inhibitors in LiFSI electrolytes. Through a systematic comparison among lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), and lithium difluoro(oxalato)borate (LiDFOB), and LiPF6, the inhibition ability of the additives is revealed to be in the following order: LiDFOB > LiBF4 ≈ LiPF6 > LiBOB. In particular, the inhibition effect of LiDFOB is outstanding; the anodic behavior of Al in 0.8 M LiFSI + 0.2 M LiDFOB ethylene carbonate (EC)-based electrolyte is comparable to that of corrosion-free 1 M LiPF6 solution. The superior inhibition ability of LiDFOB is attributed to the formation of a passive layer composed of Al-F, Al2O3, and B-O species, as evidenced by X-ray photoelectron spectroscopy (XPS) measurements. A LiCoO2/graphite cell with 0.8 M LiFSI + 0.2 M LiDFOB electrolyte exhibits a rate capability comparable to a cell with 1 M LiPF6 solution, whereas a cell with 0.8 M LiFSI solution without LiDFOB suffers from poor power performance resulting from severe Al corrosion.

  12. Laser Photolysis Studies on Pyrene in Ionic Liquids and Conventional Solvents%芘在离子液体及常规溶剂中的激光闪光光解研究

    Institute of Scientific and Technical Information of China (English)

    付海英; 邢兆国; 吴国忠

    2011-01-01

    利用纳秒级时间分辨激光光解装置,以Nd:YAG激光器三倍频后的355 nm激光作为激发光源,研究了芘在常规溶剂乙腈、丙酮、环己烷、1-丁基-3-甲基咪唑六氟磷酸离子液体([Bmim][PF6])、N-丁基吡啶四氟硼酸离子液体([BuPy][BF4])以及三乙基庚基铵双三氟甲磺酰亚胺(R4NNTf2)的瞬态光解行为,比较了芘在各类体系中的瞬态光谱及反应动力学行为.研究表明芘在离子液体中各类瞬态物种的寿命均较常规溶剂延长,且反应速率常数随着离子液体的类型的变化而不同.与[Bmim][PF6]和R4NNTf2相比,[BuPy][BF4]最为活泼,认为主要是由于[BuPy][BF4]自身参加了反应.%The photochemistry of pyrene in conventional solvents (acetone, acetonitrile, cyclohexane) and ionic liquids [Bmim][PF6 ], [BuPy][BF4 ], R4 NNTf2 was investigated by time-resolved laser photolytic techniques. The transient absorption spectra of the excited pyrene and other radical species were compared. The absorption hand of pyrene cation radical was observed in the acetone, acetronitrile and pyridiniurn ionic liquid [BuPy][BF4 ] systems. Only excited triplet pyrene was observed in cyclohexane and [Bmim][PF6 ] and R4 NNTf2. The result demonstrates that there was an interaction between pyrene and solvents, and the pyrene cation radical was formed by electron transfer from the excited state of pyrene to acetonitrile, acetone and [BuPy][BF4 ].The possible mechanisms of the six systerna were suggested.

  13. Transition metal complexes with thiosemicarbazide-based ligands. Part46. Synthesis and physico-chemical characterization of mixed ligand cobalt(III-complexes with salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine

    Directory of Open Access Journals (Sweden)

    VUKADIN M. LEOVAC

    2003-12-01

    Full Text Available Mixed ligand octahedral cobalt(III complexes with the tridentate salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine of general formula [CoIII(L11-3(py3]X (H2L1 = salicylaldehyde semicarbazone, X = [CoIICl3(py]-, ClO4- . H2O, I- . 0.5 I2; H2L2 = salicylaldehyde thiosemicarbazone, X = [CoIICl3(py]-, [CoIIBr3(py]-, ClO4- . H2O, I3-; H2L3 = salicylaldehyde S-methylisothiosemicarbazone, X = [ CoIIBr3(py ]-, ClO4- . H2O, BF4- were synthesized. The tridentate coordination of all the three dianionic forms of the ligands involves the phenol oxygen, hydrazine nitrogen and the chalcogen (O or S in case of salicylaldehyde semi-, thiosemicarbazone and the terminal nitrogen atom in the case of isothiosemicarbazone. For all the complexes, a meridial octahedral arrangement is proposed, which is a consequence of the planarity of the chelate ligand. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility, IR and electronic absorption spectra. The thermal decomposition of the complexes was investigated by thermogravimetry, coupled TG-MS measurements and DSC.

  14. Conductivity and thermopower studies of bis-tetramethyltetraselenafulvalenium hexafluorophosphide, bis-tetramethyltetrathiafulvalenium hexafluorophosphide, and their solid solutions, (TMTSF1-xTMTTFx)2PF6

    DEFF Research Database (Denmark)

    Mortensen, Kell; Engler, E. M.

    1984-01-01

    are attributed to the small transverse transfer integral tb associated with the TMTTF molecule, which leads to large on-site Coulomb repulsion. The parallel transfer integrals ta appear to be very similar for the two constituent molecules. A slight x dependence of S, appearing below approximately 100 K......, is attributed to enhanced one-dimensionality when the amount of TMTTF is increased. Close to and below the spin-density-wave ordering temperature, more marked x dependences appear, indicative of impurities. The x=0.85 salt behaves generally similar to the pristine TMTTF material, though dominated by additional...

  15. Preparation of Ionic Liquids and Their Application in Hydrogenation of Aromatic Nitriles

    Institute of Scientific and Technical Information of China (English)

    LIN,Qi; CHEN,Li; XIE,Yi-Peng; ZHENG,Hong-Jie; LI,Xian-Jun; CHEN,Hua

    2004-01-01

    @@ On the basis of their characteristic polar nature, phase behavior and lack of vapour pressure, ionic liquids are considered as green solvents and have attracted significant attention as an alternative reaction medium for homogeneous catalysis.[1] However, the "greenness" of typical ionic liquids used in the literature consisted of halogen-containing anions (such as [AlCl4]-, [BF4]- and [PF6]-) was limited in some sense, due to the serious environment concerns if the hydrolysis stability of the anion is poor (e.g. for [AlCl4]-and [PF6]-) or thermal stability of used ionic liquid is undesired. In both cases, the additional effort is needed to avoid the liberation of toxic and corrosive HF or HCl into the environment.

  16. Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic liquids and QSPR model

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiqin; YU Yanmei; CHEN Jian; FEI Weiyang

    2007-01-01

    The separations of olefin/paraffin,aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers.Activity coefficients γ∞ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation.In fact,the measurement of γ∞ by gas-liquid chromatography is a speedy and costsaving method.Activity coefficients at infinite dilution of hydrocarbon solutes,such as alkanes,hexenes,alkylbenzenes,styrene,in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF4]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF4]) and [MPMIM][BF4]-AgBF4 have been determined by gas-liquid chromatography using ionic liquids as stationary phase.The measurements were carried out at different temperatures from 298 to 318 K.The separating effects of these ionic liquids for alkanes/hexane,aliphatic hydrocarbons/benzene and hexene isomers have been discussed.The hydrophobic parameter,dipole element,frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method.The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed.The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

  17. Measurement and Correlation of the Ionic Conductivity of Ionic Liquid-Molecular Solvent Solutions

    Institute of Scientific and Technical Information of China (English)

    LI,Wen-Jing; HAN,Bu-Xing; TAO,Ran-Ting; ZHANG,Zhao-Fu; ZHANG,Jian-Ling

    2007-01-01

    The ionic conductivity of the solutions formed from 1-n-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) or 1-n-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) and different molecular solvents (MSs) were measured at 298.15 K. The molar conductivity of the ionic liquids (ILs) increased dramatically with increasing concentration of the MSs. It was found that the molar conductivity of the IL in the solutions studied in this work could be well correlated by the molar conductivity of the neat ILs and the dielectric constant and molar volume of the MSs.

  18. Solvation free energies in [bmim]-based ionic liquids: Anion effect toward solvation of amino acid side chain analogues

    Science.gov (United States)

    Latif, Muhammad Alif Mohammad; Micaêlo, Nuno; Abdul Rahman, Mohd Basyaruddin

    2014-11-01

    Stochastic molecular dynamics simulations were performed to investigate the solvation free energy of 15 neutral amino acid side chain analogues in aqueous and five, 1-butyl-3-methylimidazolium ([BMIM])-based ionic liquids. The results in aqueous were found highly correlated with previous experimental and simulation data. Meanwhile, [BMIM]-based RTILs showed better solvation thermodynamics than water to an extent that they were capable of solvating molecules immiscible in water. Non-polar analogues showed stronger solvation in hydrophobic RTIL anions such as [PF6]- and [Tf2N]- while polar analogues showed stronger solvation in the more hydrophilic RTIL anions such as [Cl]-, [TfO]- and [BF4]-.

  19. Electrochemical characterization of electrolytes and electrodes for lithium-ion batteries. Development of a new measuring method for electrochemical investigations on electrodes with the electrochemical quartz crystal microbalance (EQCM); Elektrochemische Charakterisierung von Elektrolyten und Elektroden fuer Lithium-Ionen-Batterien. Entwicklung einer neuen Messmethode fuer elektrochemische Untersuchungen an Elektroden mit der EQCM

    Energy Technology Data Exchange (ETDEWEB)

    Moosbauer, Dominik Johann

    2010-11-09

    In this work the conductivities of four different lithium salts, LiPF6, LiBF4, LiDFOB, and LiBOB in the solvent mixture EC/DEC (3/7) were investigated. Furthermore, the influence of eight ionic liquids (ILs) as additives on the conductivity and electrochemical stability of lithium salt-based electrolytes was studied. The investigated salts were the well-known lithium LiPF6 and LiDFOB. Conductivity studies were performed over the temperature range (238.15 to 333.15) K. The electrochemical stabilities of the solutions were determined at aluminum electrodes. The salt solubility of LiBF4 and LiDFOB in EC/DEC (3/7) was measured with the quartz crystal microbalance (QCM), a method developed in our group. Moreover, a method to investigate interactions between the electrolyte and electrode components with the electrochemical quartz crystal microbalance (EQCM) was developed. First, investigations of corrosion and passivation effects on aluminum with different lithium salts were performed and masses of deposited products estimated. Therefore, the quartzes were specially prepared with foils. Active materials of cathodes, in this work lithium iron phosphate (LiFePO4), were also investigated with the EQCM by a new method. [German] In dieser Arbeit wurden die Leitfaehigkeiten von vier unterschiedlichen Salzen, LiPF6, LiBF4, LiDFOB und LiBOB in dem Loesemittelgemisch EC/DEC (3/7) untersucht. Des Weiteren wurde der Einfluss von acht Ionischen Fluessigkeiten (ILs) als Additive fuer Lithium-Elektrolyte auf die elektrochemische Stabilitaet und die Leitfaehigkeit studiert. Die untersuchten Salze waren LiPF6 und LiDFOB. Die Leitfaehigkeitsmessungen wurden in einem Temperaturbereich von (238,15 bis 333,15) K durchgefuehrt. Die elektrochemischen Stabilitaeten der Elektrolyte fanden an Aluminium statt. Mit einer an der Arbeitsgruppe entwickelten neuen Methode wurden zudem die Salzloeslichkeiten von LiBF4 und LiDFOB in EC/DEC (3/7) mit der Quarzmikrowaage (QCM) bestimmt. Weiterhin wurden

  20. Preparation and Characterization of New Type Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new type of ionic liquids containing cation of diacetone acrylamide [or N-(1,1- bismethyl-3-oxo-butyl)acrylamide] and anions such as CH3COO-(Ac), CF3COO(-(TF), BF4-(BF), PF6-(PF), HSO4-(SO) and Cl-(Cl) were prepared by normal neutralization.The obtained ionic liquids were identified by FT-IR and 1H NMR spectroscopy.However, their properties such as melting point, conductivity, viscosity etc.were determined.

  1. Metathesis of Fatty Acid Ester Derivatives in 1,1-Dialkyl and 1,2,3-Trialkyl Imidazolium Type Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Priya A. Thomas

    2011-06-01

    Full Text Available The self-metathesis of methyl oleate and methyl ricinoleate was carried out in the presence of ruthenium alkylidene catalysts 1–4 in [bmim] and [bdmim][X] type ionic liquids (RTILs (X = PF6−, BF4– and NTf2− using the gas chromatographic technique. Best catalytic performance was obtained in [bdmim][X] type ionic liquids when compared with [bmim][X] type ionic liquids. Catalyst recycling studies were also carried out in the room temperature ionic liquids (RTILs with catalysts 1–4 in order to explore their possible industrial application.

  2. Activity and stability of feruloyl esterase A from Aspergillus niger in ionic liquid systems

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Riisager, Anders; Meyer, Anne S.

    by the quantum chemistry-based COSMO-RS method, [BF4]- has a tendency to form hydrogen bonds and thus interfere with the secondary structure of the enzyme, while [PF6]-is unlikely to form hydrogen bonds and therefore does not cause denaturation of the enzyme. Similar results have been obtained for lipases [1......], but this is the first report on FAE stability in ILs [2]. COSMO-RS, which is now widely used for solvent screening in the complex IL systems [3], may be a valuable tool for fast enzyme stability predictions and/or solvent screening in the future....

  3. The preparation of carbon dots/ionic liquids-based electrolytes and their applications in quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: ► A facile means to generate carbon dots/ionic liquids (ILs) – were demonstrated. ► The carbon dots/ILs blend were used for fabricating quasi-solid-state DSSCs. ► Cells exhibited good stability in room temperature without any further sealing. -- Abstract: A facile means to generate carbon dots/ionic liquids (ILs) blend using ionic liquid-assisted electrochemical exfoliation was demonstrated. Two kinds of ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), were used in this work. Transmission electron microscopy and UV–vis spectrum were employed to characterize the formed carbon dots/ILs. The carbon dots/ILs were used for fabricating quasi-solid-state dye-sensitized solar cells (DSSCs), where 1-butyl-3-methylimidazolium iodide and LiI/I2 were added to enhance the performance of DSSCs. Effects of the varied contents of components in the complex on the performance of DCCSs have been studied in detail at ambient temperature. The electrochemical impedance spectroscopy showed that the introduction of carbon dots into ionic liquids can enhance the electrical properties by facilitating charge transfer processes of the electrolytes. The overall energy-conversion efficiency (η) was 2.71% and 2.41% for carbon dots/[bmim][PF6] and carbon dots/[bmim][BF4] based blend electrolytes, respectively. A 82% enhancement in η was obtained by introduction of carbon dots into [bmim][PF6] comparing with pure [bmim][PF6] (η = 1.49%). In addition, the cells exhibited good stability under continuous illumination in room temperature without any further sealing

  4. Mixed-Salt/Ester Electrolytes for Low-Temperature Li+ Cells

    Science.gov (United States)

    Smart, Marshall; Bugga, Ratnakumar

    2006-01-01

    Electrolytes comprising, variously, LiPF6 or LiPF6 plus LiBF4 dissolved at various concentrations in mixtures of alkyl carbonates and alkyl esters have been found to afford improved low-temperature performance in rechargeable lithium-ion electrochemical cells. These and other electrolytes have been investigated in a continuing effort to extend the lower limit of operating temperatures of such cells. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles, the most recent being Ester-Based Electrolytes for Low-Temperature Li-Ion Cells (NPO-41097), NASA Tech Briefs, Vol. 29, No. 12 (December 2005), page 59. The ingredients of the solvent mixtures include ethylene carbonate (EC), ethyl methyl carbonate (EMC), methyl butyrate (MB), and methyl propionate (MP). The electrolytes were placed in Li-ion cells containing carbon anodes and LiNi0.8Co0.2O2 cathodes, and the electrical performances of the cells were measured over a range of temperatures down to 60 C. The electrolytes that yielded the best low-temperature performances were found to consist, variously, of 1.0 M LiPF6 + 0.4 M LiBF4 or 1.4 LiPF6 in 1EC + 1EMC + 8MP or 1EC + 1EMC + 8MB, where the concentrations of the salts are given in molar units and the proportions of the solvents are by relative volume.

  5. Effect of Lithium Bis(trifluoromethylsulfonyl)imide on the High-temperature Behavior of LiFePO4 Positive Electrode%二(三氟甲基磺酰)亚胺锂对磷酸铁锂正极高温行为的影响

    Institute of Scientific and Technical Information of China (English)

    车海英; 杨军; 吴凯; 王久林; 努丽燕娜

    2011-01-01

    The effect of lithium salts in electrolytes on the high-temperature performance of LiFePO4 electrode is investigated systematically and the related mechanism is revealed. Differential scanning calorimetry measurements show that lithium bis(trifluorornethylsulfonyl)imide (LiTFSI) and LiBF4 are more favorable for the use at high temperature than LiPF6 because of their water insensitivities and excellent thermal stabilities. Inductively coupled plasma is used to examine the dissolving degree of ferrous ions from LiFePO4 in the different electrolytes at 55℃. It is found that little ferrous ions can be dissolved from LiFePO4 in LiTFSI and fluorine-free lithium salt electrolytes. On the contrary, it is quite serious in LiPF6 electrolyte. In addition, FePO4 is easier to release iron ions than LiFePO4 in the LiPF6 electrolyte. The experimental results of cyclic voltammetry and light microscope indicate that a small amount of LiBF4 can inhibit the corrosion of aluminum foil current collector from LiTFSI. The electrolyte containing mixed salts of LiTFSI and LiBF4 significantly improves the high-temperature performance of LiFePCVLi cell. The discharge capacity is still 147.7 mAh/g after 40 cycles at 55℃ and 1 C rate.%系统研究了电解质锂盐对磷酸铁锂电极高温性能的影响,并探讨了相关的作用机理.差示扫描量热仪测试显示,与LiPF6相比,二(三氟甲基磺酰)亚胺锂(LiTFSI)和LiBF4具有对水份稳定且热稳定性好的优点,更适合高温条件下使用.应用等离子体发射光谱考察LiFePO4在55℃和不同电解液体系中铁离子溶出程度,结果表明,在LiTFSI和无氟锂盐电解液中LiFePO4的铁很少溶出,而在LiPF6电解液中却溶出严重,且FePO4的铁溶出量高于LiFePO4.循环伏安和光学显微镜测试结果显示少量LiBF4的加入能有效抑制LiTFSI对集流体铝箔的腐蚀.以LiTFSI和LiBF4作为混合锂盐配成的电解液能显著改善LiFePO4/Li电池的高温电化学性能,在55

  6. Comprehensive Insights into the Reactivity of Electrolytes Based on Sodium Ions.

    Science.gov (United States)

    Eshetu, Gebrekidan Gebresilassie; Grugeon, Sylvie; Kim, Huikyong; Jeong, Sangsik; Wu, Liming; Gachot, Gregory; Laruelle, Stephane; Armand, Michel; Passerini, Stefano

    2016-03-01

    We report a systematic investigation of Na-based electrolytes that comprise various NaX [X=hexafluorophosphate (PF6 ), perchlorate (ClO4 ), bis(trifluoromethanesulfonyl)imide (TFSI), fluorosulfonyl-(trifluoromethanesulfonyl)imide (FTFSI), and bis(fluorosulfonyl)imide (FSI)] salts and solvent mixtures [ethylene carbonate (EC)/dimethyl carbonate (DMC), EC/diethyl carbonate (DEC), and EC/propylene carbonate (PC)] with respect to the Al current collector stability, formation of soluble degradation compounds, reactivity towards sodiated hard carbon (Nax -HC), and solid-electrolyte interphase (SEI) layer formation. Cyclic voltammetry demonstrates that the stability of Al is highly influenced by the nature of the anions, solvents, and additives. GC-MS analysis reveals that the formation of SEI telltales depends on the nature of the linear alkyl carbonates and the battery chemistry (Li(+) vs. Na(+) ). FTIR spectroscopy shows that double alkyl carbonates are the main components of the SEI layer on Nax -HC. In the presence of Na salts, EC/DMC and EC/DEC presented a higher reactivity towards Nax -HC than EC/PC. For a fixed solvent mixture, the onset temperature follows the sequence NaClO4 PF6 PF6

  7. 离子液体-CmimPF6分离提纯虾、蟹壳中壳聚糖的研究%Study on Chitosan of Shrimp and Crab Shell by Extracting with Ionic Liquid - CmimPF6

    Institute of Scientific and Technical Information of China (English)

    陶海霞; 廖芳丽; 车剑锋

    2009-01-01

    利用离子液的强溶解性,对虾、蟹粉中的壳聚糖进行分离提纯,与传统方法比较,其提取工艺简单,产率高.而且其它各项综合性能指标均优,离子液体可回收,并减少环境污染.

  8. Anion Complexes with Tetrazine-Based Ligands: Formation of Strong Anion-π Interactions in Solution and in the Solid State.

    Science.gov (United States)

    Savastano, Matteo; Bazzicalupi, Carla; Giorgi, Claudia; García-Gallarín, Celeste; López de la Torre, Maria Dolores; Pichierri, Fabio; Bianchi, Antonio; Melguizo, Manuel

    2016-08-15

    Ligands L1 and L2, consisting of a tetrazine ring decorated with two morpholine pendants of different lengths, show peculiar anion-binding behaviors. In several cases, even the neutral ligands, in addition to their protonated HL(+) and H2L(2+) (L = L1 and L2) forms, bind anions such as F(-), NO3(-), PF6(-), ClO4(-), and SO4(2-) to form stable complexes in water. The crystal structures of H2L1(PF6)2·2H2O, H2L1(ClO4)2·2H2O, H2L2(NO3)2, H2L2(PF6)2·H2O, and H2L2(ClO4)2·H2O show that anion-π interactions are pivotal for the formation of these complexes, although other weak forces may contribute to their stability. Complex stability constants were determined by means of potentiometric titration in aqueous solution at 298.1 K, while dissection of the free-energy change of association (ΔG°) into its enthalpic (ΔH°) and entropic (TΔS°) components was accomplished by means of isothermal titration calorimetry measurements. Stability constants are poorly regulated by anion-ligand charge-charge attraction. Thermodynamic data show that the formation of complexes with neutral ligands, which are principally stabilized by anion-π interactions, is enthalpically favorable (-ΔG°, 11.1-17.5 kJ/mol; ΔH°, -2.3 to -0.5 kJ/mol; TΔS°, 9.0-17.0 kJ/mol), while for charged ligands, enthalpy changes are mostly unfavorable. Complexation reactions are invariably promoted by large and favorable entropic contributions. The importance of desolvation phenomena manifested by such thermodynamic data was confirmed by the hydrodynamic results obtained by means of diffusion NMR spectroscopy. In the case of L2, complexation equilibria were also studied in a 80:20 (v/v) water/ethanol mixture. In this mixed solvent of lower dielectric constant than water, the stability of anion complexes decreases, relative to water. Solvation effects, mostly involving the ligand, are thought to be responsible for this peculiar behavior.

  9. Synthesis of fluorene-based polyelectrolytes tethering different counterions for single-component white light-emitting electrochemical cells

    Science.gov (United States)

    Yang, Sheng-Hsiung; Tsai, Chia-Sheng; Liu, Bo-Cun; Su, Hai-Ching

    2013-09-01

    A series of polyfluorene (PF) electrolytes bearing Br-, BF4 -, or PF6 - counterions were synthesized and characterized. 2,1,3-benzoselenadiazole moieties were incorporated into polymer main chains to produce single-component white lightemitting polymers. The thermal stability of Br-containing ionic PF was decreased because of the Hofmann elimination occurred at higher temperature. By replacing Br- with BF4 - or PF6 - counterions, the thermal stability of polymers was significantly improved. The emission intensity around 550 nm was decreased for ionic polyelectrolytes. The optimized spin-coated light-emitting electrochemical cell (LEC) with the configuration of ITO/PEDOT/polymer/Ag showed a maximum luminescence efficiency of 1.56 lm/W at a low operation bias of 3 V. The single-component LEC device exhibited pure white light emission with CIE'1931 coordinates approaching (0.33, 0.33) and high color rendering index (CRI < 85), referring to its potential use in solid-state-lighting application.

  10. 离子液体/有机两相催化新进展%Recent Advances in Ionic liquid -organic Biphasic Catalysis

    Institute of Scientific and Technical Information of China (English)

    焦国柱

    2012-01-01

    综述了近年来离子液体/有机两相均相催化的研究进展,重点介绍了基于氟硼酸根(BF4-)或氟磷酸根(PF6-)的咪唑类离子液体在均相催化加氢、氢甲酰化、齐聚、Heck反应中的应用,并对离子液体/有机两相催化工业应用的前景进行了探讨。%The development of ionic liquid - organic two - phasic catalysis was summerized, the applications of imid- azole class ionic liquid based were introduced with emphasis based on the fluoboric acid anion ( BF4- ) or the hexafluoro- phosphoric acid anion (PF6- ) in homogeneous catalysis hydrogenation, hydroformylation, oligomerization, Heek reaction, and the future applications of ionic liquid - organic biphasic catalysis in chemical industry were commented.

  11. Research progress on application of ionic liquid-organic biphasic catalysis%离子液体/有机两相催化应用研究进展

    Institute of Scientific and Technical Information of China (English)

    李玉成; 王恒生; 程艳婷; 郭振美

    2011-01-01

    作者就近年来离子液体/有机两相催化在加氢、氢甲酰化、齐聚、Heck反应和羰基化反应中的研究进展进行了综述,重点介绍了基于氟硼酸根(BF4-)或氟磷酸根(PF6 -)的咪唑类离子液体在均相催化反应中的应用,并对离子液体/有机两相催化工业应用的前景进行了探讨.%This paper described the development of ionic liquid-organic biphasic catalysis in hydrogena-tion,hydroformylation,oligomerization, Heck reaction and carbonylation,introduced emphatically the applications of imidazole class ionic liquid based on the fluoboric acid anion (BF4- ) or the hexafluoro-phosphoric acid anion (PF6- ) in the homogeneous catalysis,and commented the future applications of ionic liquid-organic biphasic catalysis in chemical industry.

  12. Several novel N-donor tridentate ligands formed in chemical studies of new fac-Re(CO)3 complexes relevant to fac-99mTc(CO)3 radiopharmaceuticals: attack of a terminal amine on coordinated acetonitrile.

    Science.gov (United States)

    Perera, Theshini; Marzilli, Patricia A; Fronczek, Frank R; Marzilli, Luigi G

    2010-03-01

    To evaluate syntheses of fac-[Re(CO)(3)L](+) complexes in organic solvents, we treated fac-[Re(CO)(3)(CH(3)CN)(3)]PF(6)/BF(4) in acetonitrile with triamine ligands (L). When L had two primary or two tertiary terminal amine groups, the expected fac-[Re(CO)(3)L](+) complexes formed. In contrast, N,N-dimethyldiethylenetriamine (N,N-Me(2)dien) formed an unusual compound, fac-[Re(CO)(3)(DAE)]BF(4) {DAE = (Z)-N'-(2-(2-(dimethylamino)ethylamino)ethyl)acetimidamide = (Me(2)NCH(2)CH(2))NH(CH(2)CH(2)N=C(NH(2))Me)}. DAE is formed by addition of acetonitrile to the N,N-Me(2)dien terminal primary amine, converting this sp(3) nitrogen to an sp(2) nitrogen with a double bond to the original acetonitrile sp carbon. The three Ns bound to Re derive from N,N-Me(2)dien. The pathway to fac-[Re(CO)(3)(DAE)]BF(4) is suggested by a second unusual compound, fac-[Re(CO)(3)(MAE)]PF(6) {MAE = N-methyl-N-(2-(methyl-(2-(methylamino)ethyl)amino)ethyl)acetimidamide = MeN(H)-CH(2)CH(2)-N(Me)-CH(2)CH(2)-N(Me)-C(Me)=NH}, isolated after treating fac-[Re(CO)(3)(CH(3)CN)(3)]PF(6) with N,N',N''-trimethyldiethylenetriamine (N,N',N''-Me(3)dien). MAE chelates via a terminal and a central sp(3) N from N,N',N''-Me(3)dien and via one sp(2) NH in a C(Me)=NH group. This group is derived from acetonitrile by addition of the other N,N',N''-Me(3)dien terminal amine to the nitrile carbon. This addition creates an endocyclic NMe group within a seven-membered chelate ring. The structure and other properties of fac-[Re(CO)(3)(MAE)]PF(6) allow us to propose a reaction scheme for the formation of the unprecedented DAE ligand. The new compounds advance our understanding of the spectral and structural properties of Re analogues of (99m)Tc radiopharmaceuticals. PMID:20104873

  13. Strongly luminous tetranuclear gold(I) complexes supported by tetraphosphine ligands, meso- or rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane.

    Science.gov (United States)

    Tanase, Tomoaki; Otaki, Risa; Nishida, Tomoko; Takenaka, Hiroe; Takemura, Yukie; Kure, Bunsho; Nakajima, Takayuki; Kitagawa, Yasutaka; Tsubomura, Taro

    2014-02-01

    A series of tetragold(I) complexes supported by tetraphosphine ligands, meso- and rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane (meso- and rac-dpmppm) were synthesized and characterized to show that the tetranuclear Au(I) alignment varies depending on syn- and anti-arrangements of the two dpmppm ligands with respect to the metal chain. The structures of syn-[Au4 (meso-dpmppm)2X]X'3 (X = Cl; X' = Cl (4 a), PF6 (4 b), BF4 (4 c)) and syn-[Au4 (meso-dpmppm)2]X4 (X = PF6 (4 d), BF4 (4 e), TfO (4 f); TfO = triflate) involved a bent tetragold(I) core with a counter anion X incorporated into the bent pocket. Complexes anti-[Au4 (meso-dpmppm)2]X4 (X = PF6 (5 d), BF4 (5 e), TfO (5 f)) contain a linearly ordered Au4 string and complexes syn-[Au4 (rac-dpmppm)2X2]X'2 (X = Cl, X' = Cl (6 a), PF6 (6 b), BF4 (6 c)) and syn-[Au4 (rac-dpmppm)2]X4 (X = PF6 (6 d), BF4 (6 e), TfO (6 f)) consist of a zigzag tetragold(I) chain supported by the two syn-arranged rac-dpmppm ligands. Complexes 4 d-f, 5 d-f, and 6 d-f with non-coordinative large anions are strongly luminescent in the solid state (λmax = 475-515 nm, Φ = 0.67-0.85) and in acetonitrile (λmax = 491-520 nm, Φ = 0.33-0.97); the emission was assigned to phosphorescence from (3) [dσ*σ*σ* pσσσ] excited state of the Au4 centers on the basis of DFT calculations as well as the long lifetime (a few μs). The emission energy is predominantly determined by the HOMO and LUMO characters of the Au4 centers, which depend on the bent (4), linear (5), and zigzag (6) alignments. The strong emissions in acetonitrile were quenched by chloride anions through simultaneous dynamic and static quenching processes, in which static binding of chloride ions to the Au4 excited species should be the most effective. The present study demonstrates that the structures of linear tetranuclear gold(I) chains can be modified by utilizing the stereoisomeric tetraphosphines, meso- and rac-dpmppm, which may

  14. Solubilities of p-coumaric and caffeic acid in ionic liquids and organic solvents

    International Nuclear Information System (INIS)

    Highlights: ► New solubility data of p-coumaric and caffeic acid in ionic liquids and organic solvents. ► Normal melting point temperature and enthalpy of fusion of p-coumaric and caffeic acid. ► Thermogravimetric analysis for p-coumaric and caffeic acid. ► Correlation with UNIQUAC and NRTL. -- Abstract: The solubilities of two cinnamic acid derivatives, namely p-coumaric acid and caffeic acid, in six 1-alkyl-3-methyl imidazolium based ionic liquids composed of the PF6−, BF4−, TFO− and TF2N− anions, and in two organic solvents, t-pentanol and ethyl acetate, have been measured at the temperature range of about (303 to 317) K. The p-coumaric acid was found to be more soluble than caffeic acid in all studied solvents. Higher solubilities of both acids were observed in the ionic liquids composed of the BF4− and TFO− anions. The increase of the alkyl chain length on the cation invokes a decrease in solubility in the case of hydrophilic ionic liquids composed of BF4− anion, while in the case of hydrophobic ones composed of PF6− anion an increase in the solubility is observed. Between the two organic solvents t-pentanol is better solvent than ethyl acetate for both acids. Moreover, using the van’t Hoff equations the apparent Gibbs energy, enthalpy, and entropy of solution were calculated. Finally, successful correlation of the experimental data was achieved with the UNIQUAC and the NRTL activity coefficient models, while poor predictions of the solubility of the two acids in the organic solvents were obtained with two UNIFAC models

  15. Synthesis of Nano-sized Yttria via a Sol-Gel Process Based on Hydrated Yttrium Nitrate and Ethylene Glycol and Its Catalytic Performance for Thermal Decomposition of NH4 ClO4

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nano-sized yttria particles were synthesized via a non-aqueous sol-gel process based on hydrated yttrium nitrate and ethylene glycol. The effects of the molar ratio of ethylene glycol to yttrium ion and calcination temperature on crystallite size of the products were studied. The catalytic performance of the as-prepared yttria for the ammonium perchlorate (AP) decomposition was investigated by differential scanning calorimetry (DSC). The results indicate that the nano-sized cubic yttria particles with less than 20 nm in average crystallite size can be obtained after 2 h reflux at 70 ℃, dried at 90 ℃, forming xerogel, and followed by annealing of xerogel for 2 h, and that the addition of the nano-sized yttria to AP incorporates two small exothermic peaks of AP in the temperature ranges of 310 ~ 350 ℃ and 400 ~ 470 ℃ into a strong exothermic peak of AP and increases the apparent decomposition heat from 515 to over 1110 J·g-1. It is also clear that the temperature of AP decomposition exothermic peak decreases and the apparent decomposition heat of AP increases with the increase of the amount of nano-sized yttria. The fact that the addition of the 5 % nano-sized yttria to AP decreases the temperature of AP exothermic peak to 337.7 ℃ by reduction of 114.6 ℃ and increases the apparent decomposition heat from 515 to 1240 J·g-1, reveals that nano-sized yttria shows strong catalytic property for AP thermal decomposition.

  16. Novel superconducting phenomena in quasi-one-dimensional Bechgaard salts

    Science.gov (United States)

    Jerome, Denis; Yonezawa, Shingo

    2016-03-01

    It is the saturation of the transition temperature Tc in the range of 24 K for known materials in the late sixties that triggered the search for additional materials offering new coupling mechanisms leading in turn to higher Tc's. As a result of this stimulation, superconductivity in organic matter was discovered in tetramethyl-tetraselenafulvalene-hexafluorophosphate, (TMTSF)2PF6, in 1979, in the laboratory founded at Orsay by Professor Friedel and his colleagues in 1962. Although this conductor is a prototype example for low-dimensional physics, we mostly focus in this article on the superconducting phase of the ambient-pressure superconductor (TMTSF)2ClO4, which has been studied most intensively among the TMTSF salts. We shall present a series of experimental results supporting nodal d-wave symmetry for the superconducting gap in these prototypical quasi-one-dimensional conductors. xml:lang="fr"

  17. 离子液体中过氧钨配合物催化氧化燃油脱硫%Oxidative desulfurization of fuels catalyzed by peroxotungsten complex in ionic liquids

    Institute of Scientific and Technical Information of China (English)

    朱文帅; 巢艳红; 李华明; 尹盛; 蒋伟; 朱国鹏

    2011-01-01

    A peroxo-tungsten amino acid complex WO(O2)2 · 2C3H7NO2 · H2Owas synthesized with D,L-alanine as ligand. In the case of WO(O2)2 · 2C3H7NO2 · H2O/[Bmim]PF6/H2O2 desulfurization system,detailed experiments were plotted including reac-tion time,temperature, amount of catalyst and so on. It was found that dibenzothiophene(DBT) removal could achieved 98. 7% , 96.7% ,98.7%and 99.0%in[Bmim]PF6,[Bmim]PF6,[Omim]BF4 and[Omim]PF6 under the optimized conditions of 70℃, re-action for 20 min,molar ratio of H2O2 ,DBT and Catalyst = 30 :10 =1,amount of ionic liquid was 1 mL This experiment demonstrated that a combination of catalytic oxidation and extraction in IL colud deeply remove DBT from model oiL This result also indicated the remarkable advantage of this process over the desulfurization by mere solvent extraction with IL or catalytic oxidation without IL%合成了一种含D,L-丙氨酸配体的钨的过氧配合物WO(O2)2·2C3H7NO2·H2O催化剂.以WO(O2)2·2C3H7NO2·H2O/[Bmim]PF6/H2O2体系为研究模型,考察了反应时间、温度和催化剂用量等因素对燃油脱硫率的影响.结果表明,在70℃反应2h,n(H2O2)∶n(二苯并噻吩)∶n(催化剂)=30∶10∶1,离子液体用量1mL,模型油中二苯并噻吩脱除率在[Bmim]BF4、[Omim]BF4、[Bmim]PF6和[Omim]PF6中分别为97.3%、96.7%、98.7%和99.0%.实验结果进一步表明,离子液体萃取耦合催化氧化脱硫法能实现深度脱硫,且该方法优于仅用离子液体萃取脱硫或不使用离子液体的催化氧化脱硫法.

  18. Effect of Ionic Liquids on Catalytic Characteristics of Horse Liver Alcohol Dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    SHI Xian-Ai; ZONG Min-Hua; LOU Wen-Yong

    2006-01-01

    The catalytic characteristics of horse liver alcohol dehydrogenase (HLADH) in the systems involving ionic liquids (Ils) (BMIm·Cl, BMIm·Br, BMIm·pF6, BMIm·BF4 BMIm·Otf and EMIm·Cl) were examined. HLADH displayed higher oxidation activity towards ethanol in the systems containing BMIm·Cl, BMIm·Br, EMIm·Cl or BMIm·PF6 with proper content than that in the IL-free buffer. An excessive amount of these Ils in the reaction systems resulted in an obvious decline in enzymatic activity. BMIm·BF4 and BMIm·Otf of any content investigated could considerably inhibit the enzyme. The anions of Ils showed significant effect on the activity, kinetic parameters and activation energy of HLADH-mediated ethanol oxidation. Additionally, BMIm·Cl, BMIm·Br,EMIm·Cl and BMIm·pF6 boosted markedly the thermostability of HLADH, while the enzyme was less thermostable in BMIm·BF4 or BMIm·Otf-containing systems. The associated conformational changes in HLADH caused by Ils were examined by UV technique.

  19. Anion-Directed Copper(II) Metallocages, Coordination Chain, and Complex Double Salt: Structures, Magnetic Properties, EPR Spectra, and Density Functional Study.

    Science.gov (United States)

    Wu, Jing-Yun; Zhong, Ming-Shiou; Chiang, Ming-Hsi; Bhattacharya, Dibyendu; Lee, Yen-Wei; Lai, Long-Li

    2016-05-17

    A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nβ, which would explain the presence of the larger TIP term.

  20. Structural insights into the counterion effects on the manganese(III) spin crossover system with hexadentate Schiff-base ligands.

    Science.gov (United States)

    Wang, Shi; Xu, Wu-Tan; He, Wen-Rui; Takaishi, Shinya; Li, Yong-Hua; Yamashita, Masahiro; Huang, Wei

    2016-04-01

    A series of new salts [Mn(5-MeO-sal-N-1,5,8,12)]Y (Y = ClO4 for 1, Y = BF4 for 2, Y = NO3 for 3 and Y = CF3SO3 for 4) based on the six-coordinated mononuclear manganese(iii) Schiff-base complex cation [Mn(5-MeO-sal-N-1,5,8,12)](+), has been investigated to determine the impact of counter anion effects, intramolecular ligand distortion and intermolecular supramolecular structures on the spin crossover (SCO) behavior. The SCO in salt 1 has resulted in a crystallographic observation of the coexistence of high-spin (HS, S = 2) and low-spin (LS, S = 1) manganese(iii) complex cations in equal proportions around 100 K. At room temperature, the two crystallographically distinct manganese centers are both close to the complete HS state. Only one of the two slightly different units undergoes SCO in the temperature range 300-180 K, whereas the other remains in the HS state down to 20 K. For salts 2 and 3, crystal structural analysis indicates change in the anion from ClO4(-) to BF4(-) and NO3(-) was led to the close arrangement of the cations and the stacking between phenyl groups from the ligands. With CF3SO3(-) as the counterion, although the cations and the anions separate clearly in one direction, the close arrangement of cations in other directions precludes the spin transformation of the Mn(iii) cations. Magnetic measurements on 2-4 indicate that the manganese(iii) complex cations remain in the HS state in the temperature range 2-300 K. PMID:26927027

  1. Hydrogen bonding and multiphonon structure in copper pyrazine coordination polymers.

    Science.gov (United States)

    Brown, S; Cao, J; Musfeldt, J L; Conner, M M; McConnell, A C; Southerland, H I; Manson, J L; Schlueter, J A; Phillips, M D; Turnbull, M M; Landee, C P

    2007-10-15

    We report a systematic investigation of the temperature-dependent infrared vibrational spectra of a family of chemically related coordination polymer magnets based upon bridging bifluoride (HF(2)-) and terminal fluoride (F-) ligands in copper pyrazine complexes including Cu(HF(2))(pyz)(2)BF(4), Cu(HF(2))(pyz)(2)ClO(4), and CuF(2)(H(2)O)(2)(pyz). We compare our results with several one- and two-dimensional prototype materials including Cu(pyz)(NO(3))(2) and Cu(pyz)(2)(ClO(4))(2). Unusual low-temperature hydrogen bonding, local structural transitions associated with stronger low-temperature hydrogen bonding, and striking multiphonon effects that derive from coupling of an infrared-active fundamental with strong Raman-active modes of the pyrazine building-block molecule are observed. On the basis of the spectroscopic evidence, these interactions are ubiquitous to this family of coordination polymers and may work to stabilize long-range magnetic ordering at low temperature. Similar interactions are likely to be present in other molecule-based magnets.

  2. Magnetic field dependence of spin-forbidden electronic excitations reflects the Haldane or paramagnetic ground state

    Science.gov (United States)

    Long, V. C.; Montague, J. R.; Kozen, A. C.; Wei, X.; Landry, B. R.; Pearson, K. R.; Turnbull, M. M.; Landee, C. P.

    2007-03-01

    We compare the zero-field and magnetic field-dependent optical spectra of the Haldane chain compound NENB (Ni[en]2NO2BF4; en = C2N2H8) and the paramagnetic compound, Ni(en) 3(ClO4)2,H2O. Due to similar electronic coordination of Ni^2+, the two materials show similar zero-field d-d electronic transitions, including a spin-forbidden (SF) transition at 1.58 eV, overlapping a broad spin-allowed band at 1.45 eV. The relatively greater intensity of the SF band in the Haldane compound suggests activation by a spin exchange mechanism, whereas a spin-orbit coupling origin is likely in the paramagnet. A second narrower SF spin flip transition appears in NENB at 1.66 eV. In both compounds, the SF excitations are sensitive to applied field H. In NENB, the SF intensity is suppressed by H, consistent with behavior of spin exchange-activated bands. In Ni(en)3(ClO4)-2,H2O, the SF field sensitivity appears to combine an energy shift and intensity decrease. Details of the H dependence reflect the magnetic ground state of the material: the field sensitivity commences only above HC 10 T, in the Haldane compound, whereas the field-induced modifications begin immediately at H = 0 T in the paramagnet.

  3. The Catalytic Characteristics of β-glucuronidase in Systems Containing Ionic liquids%离子液体对重组β-葡萄糖醛酸苷酶催化特性的影响

    Institute of Scientific and Technical Information of China (English)

    陈金燕; 刘桂艳; 李春

    2011-01-01

    The hydrolysis of P-Nitrophenyl beta-D-Galactopyranoside (pNPG) to P-Nitrophenyl (pNP) catalyzed by β-glucuroni-dase in system containing 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) or 1-butyl-3-methylimidazolium tet-rafluoroborate ([Bmim]BF4) were performed. The reactions in [Bmim]PF6/buffer biphasic system were mainly studied,and with the buffer single-phase system as control. The optimal conditions of reaction in [Bmim]PF6/buffer biphasic system were determined,the optimum ionic liquid concentration,buffer pH,substrate concentration,temperature were 40%,4. 8~6. 2,10. 0 mmol/L,35~50 ℃,respectively. The kinetics and thermodynamics parameters were as follows in [Bmim]PF6/buffer biphasic system:Vmax = 0. 153 mmoI/(L · min),Km = 0. 773 mmol/L. The activation energy of hydrolyzing of pNPG in [Bmim]PF6/ buffer biphasic system is 35. 386 kJ/moL,and in monophasic buffer system is 48. 199 kJ/moL.%研究了重组β-葡萄糖醛酸苷酶分别在含疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)和亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)的体系中催化4-硝基苯基-β-D-吡喃半乳糖苷(pNPG)生成对硝基苯酚(pNP)的反应,并以缓冲液单相反应体系作为对照,考察离子液体对酶催化反应特性的影响.结果显示:[Bmim]PF6/缓冲液两相体系中最适底物浓度为10.0 mmol/L,较缓冲液单相体系提高了1倍,确定了该体系动力学与热力学参数Vmax为0.153 mmol/(L·min),Km为0.773 mmol/L,表观活化能Ea为35.386 kJ/mol;而缓冲液单相反应体系中Vmax为0.094 mmol/(L·min),Km为0.620 mmol/L,E为48.199 kJ/moL,说表明离子液体[Bmim]PF6降低了反应活化能并提高了反应速率.

  4. A New Series of Complexes Possessing Rare “Tertiary” Sulfonamide Nitrogen-to-Metal Bonds of Normal Length: fac-[Re(CO)3(N(SO2R)dien)]PF6 Complexes with Hydrophilic Sulfonamide Ligands

    OpenAIRE

    Abhayawardhana, Pramuditha L.; Marzilli, Patricia A.; Fronczek, Frank R.; Marzilli, Luigi G.

    2014-01-01

    Tertiary sulfonamide nitrogen-to-metal bonds of normal length are very rare. We recently discovered such a bond in one class of fac-[Re(CO)3(N(SO2R)(CH2Z)2)]n complexes (Z = 2-pyridyl) with N(SO2R)dpa ligands derived from di-(2-picolyl)amine (N(H)dpa). fac-[M(CO)3(N(SO2R)(CH2Z)2)]n agents (M = 186/188Re, 99mTc) could find use as radiopharmaceutical bioconjugates when R is a targeting moiety. However, the planar, electron-withdrawing 2-pyridyl groups of N(SO2R)dpa destabilize the ligand to bas...

  5. Superconductivity in the family of organic salts based on the tetramethyltetraselenafulvalene (TMTSF) molecule: (TMTSF)2X (X = Cl04, PF6, AsF6, SbF6, TaF6)

    International Nuclear Information System (INIS)

    Resistivity measurements along the high-conductivity axis of (TMTSF)2Cl04, (TMTSF)2TaF6 and (TMTSF)2SbF6 are reported for various hydrostatic pressures up to 12.5 kbar, and for transverse magnetic fields of up to 50 kG, in the temperature range 100 mK-4 K. These measurements show that all three compounds have a superconducting phase transition near 1 K when sufficient pressure is applied. (TMTSF)2SbF6 and (TMTSF)2TaF6 become superconducting for pressures above 10 kbar and 11 kbar respectively. At lower pressures a metal-insulator phase transition is observed which is probably associated with a spin density wave (SDW) instability. A superconducting phase transition is observed in (TMTSF)2Cl04 at much lower pressures (2X salts. (author)

  6. Cu(II complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

    Directory of Open Access Journals (Sweden)

    Saha Sanjoy

    2015-01-01

    Full Text Available Two Cu(II complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II salts. The synthesized Cu(II complexes were tested for biological activity.

  7. 咪唑类离子液体的微波水浴合成及性能研究%Study on microwave-assisted synthesis and performance of imidazole ionic liquids

    Institute of Scientific and Technical Information of China (English)

    李昌家; 李景印; 李娜; 郭玉凤; 刘方方

    2012-01-01

    以N-甲基咪唑、氯代正丁烷、KPF6及NaBF4等为原料,分别在微波和水浴2种加热条件下利用二步法合成出2种咪唑类离子液体[BMIM]PF6和[BMIM]BF4.比较了2种方法在中间体合成及阴离子置换中的优势和劣势,并利用IR,TGA和LSV等方法表征了所得离子液体的结构特征及电化学性能.结果表明,2种方法所合成的离子液体在物化性质上无明显差异.微波法在合成中间体时可显著缩短反应时间,产率可达90%以上;水浴加热法则更有利于阴离子置换.故采用微波法与水浴加热法相结合的方式合成离子液体可收到良好的效果.%Two kinds of imidazole ionic liquids([BM1M]PF6 and [BMIM]BF4) are synthesized from N-methyl-midazolium, chlorobutane, KPF6 and NaBF4 under microwave irradiation and water bath heating respectively by two-step method. The advantage and disadvantage in the synthesis of intermediate and anion exchange are compared, and the structure characteristics and electrochemical performance are characterized. The result shows that the ionic liquids synthesized by two different methods have no evident discrepancy. The reaction time can be cut down markedly under the microwave, and the productivity can exceed 90% , while the water bath heating is propitious to anion exchange. So combining the two methods will get a favorable result.

  8. Ionic liquid-based hydrothermal synthesis and luminescent properties of CaF2:Ce3+/Mn2+ nanocrystals

    International Nuclear Information System (INIS)

    CaF2:Ce3+/Mn2+ sub-micro cubes and nanospheres were successfully prepared through an ionic liquid-based hydrothermal method. OmimPF6 and OmimBF4 were utilized to introduce a new fluoride source and act as templates. The effects of ionic liquid amount and species on the morphologies and sizes of the nanocrystals have been studied. The photoluminescence properties of CaF2:Ce3+/Mn2+ sub-micro cubes have been discussed, and the results show that the emission intensity of Mn2+ ions can be enhanced by co-doping with Ce3+ ions through an efficient resonance-type energy transfer process.

  9. Ion exchange synthesis and thermal characteristics of some $[\\text{N}^{+}_{2222}]$ based ionic liquids

    Indian Academy of Sciences (India)

    Vasishta D Bhatt; Kuldip Gohil

    2013-11-01

    Eight salts were obtained by reacting tetraethylammonium cation $[\\text{N}^{+}_{2222}]$ with inorganic anions like BF$^{-}_{4}$, NO$^{-}_{3}$, NO$^{-}_{2}$, SCN-, BrO$^{-}_{3}$, IO$^{-}_{3}$, PF$^{-}_{6}$ and HCO$^{-}_{3}$ using ion exchange method. These ionic liquids (ILs) were characterized using thermal methods, infrared spectroscopy and densitometry. Thermophysical properties such as density, coefficient of volume expansion, heat of fusion, heat capacity and thermal energy storage capacity were determined. Thermal conductivity of the samples was determined both in solid and liquid phases. Owing to high values of thermal energy storage capacity coupled with handsome liquid phase thermal conductivity, ILs under investigation were recommended as materials for thermal energy storage (TES) as well as heat transfer applications.

  10. Anion Solvation in Carbonate Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengcheng

    2015-11-16

    With the correlation between Li+ solvation and interphasial chemistry on anodes firmly established in Li-ion batteries, the effect of cation–solvent interaction has gone beyond bulk thermodynamic and transport properties and become an essential element that determines the reversibility of electrochemistry and kinetics of Li-ion intercalation chemistries. As of now, most studies are dedicated to the solvation of Li+, and the solvation of anions in carbonate-based electrolytes and its possible effect on the electrochemical stability of such electrolytes remains little understood. As a mirror effort to prior Li+ solvation studies, this work focuses on the interactions between carbonate-based solvents and two anions (hexafluorophosphate, PF6–, and tetrafluoroborate, BF4–) that are most frequently used in Li-ion batteries. The possible correlation between such interaction and the interphasial chemistry on cathode surface is also explored.

  11. Compatibility and thermal stability studies on plasticized PVC/PMMA blend polymer electrolytes complexed with different lithium salts

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2005-03-01

    Full Text Available The lithium salt (x (X= LiAsF6, LiPF6, LiN(C2F5SO22 , LiN(CF3SO22, LiBF4 was complexed with a host of poly(vinyl chloride (PVC/ poly(methyl methacrylate (PMMA blend polymer and plasticized with a combination of ethylene carbonate (EC and propylene carbonate(PC. The polymer electrolyte films were prepared for constant PVC/PMMA blend ratio. The electrochemical stability and thermal stability of the solid polymer electrolytes were reported. The role of PMMA to the phenomena occurring at the interface between the electrolyte and the lithium metal electrode was explored.

  12. The Anion Effect on Li+ Ion Coordination Structure in Ethylene Carbonate Solutions

    CERN Document Server

    Jiang, Bo; Shen, Yuneng; Yang, Xueming; Yuan, Kaijun; Vetere, Valentina; Mossa, Stefano; Skarmoutsos, Ioannis; Zhang, Yufan; Zheng, Junrong

    2016-01-01

    Rechargeable lithium ion batteries are an attractive alternative power source for a wide variety of applications. To optimize their performances, a complete description of the solvation properties of the ion in the electrolyte is crucial. A comprehensive understanding at the nanoscale of the solvation structure of lithium ions in nonaqueous carbonate electrolytes is, however, still unclear. We have measured by femtosecond vibrational spectroscopy the orientational correlation time of the CO stretching mode of Li+-bound and Li+-unbound ethylene carbonate molecules, in LiBF4, LiPF6, and LiClO4 ethylene carbonate solutions with different concentrations. Surprisingly, we have found that the coordination number of ethylene carbonate in the first solvation shell of Li+ is only two, in all solutions with concentrations higher than 0.5 M. Density functional theory calculations indicate that the presence of anions in the first coordination shell modifies the generally accepted tetrahedral structure of the complex, all...

  13. Magnetically rotational reactor for absorbing benzene emissions by ionic liquids

    Institute of Scientific and Technical Information of China (English)

    Yangyang; Jiang; Chen; Guo; Huizhou; Liu

    2007-01-01

    A magnetically rotational reactor (MRR) has been developed and used in absorbing benzene emissions. The MRR has a permanent magnet core and uses magnetic ionic liquid [bmim]FeCl4 as absorbent. Benzene emissions were carried by N2 into the MRR and were absorbed by the magnetic ionic liquid. The rotation of the permanent magnet core provided impetus for the agitation of the magnetic ionic liquid, enhancing mass transfer and making benzene better dispersed in the absorbent. 0.68 g benzene emissions could be absorbed by a gram of [bmim]FeCl4, 0.27 and 0.40 g/ghigher than that by [bmim]PF6 and [bmim]BF4, respectively. The absorption rate increased with increasing rotation rate of the permanent magnet.

  14. Translational diffusion in mixtures of imidazolium ILs with polar aprotic molecular solvents.

    Science.gov (United States)

    Marekha, Bogdan A; Kalugin, Oleg N; Bria, Marc; Buchner, Richard; Idrissi, Abdenacer

    2014-05-22

    Self-diffusion coefficients of cations and solvent molecules were determined with (1)H NMR in mixtures of 1-n-butyl-3-methylimidazolium (Bmim(+)) tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)), trifluoromethanesulfonate (TfO(-)), and bis(trifluoromethylsulfonyl)imide (TFSI(-)) with acetonitrile (AN), γ-butyrolactone (γ-BL), and propylene carbonate (PC) over the entire composition range at 300 K. The relative diffusivities of solvent molecules to cations as a function of concentration were found to depend on the solvent but not on the anion (i.e., IL). In all cases the values exhibit a plateau at low IL content (x(IL) inversion point of relative ionic diffusivities was found around equimolar composition and does not depend on the solvent. At this point, a distinct change in the ion-diffusion mechanism appears to take place.

  15. Pyrrole-Pyridine and Pyrrole-Naphthyridine Hosts for Anion Recognition

    Directory of Open Access Journals (Sweden)

    M. Angeles García

    2015-05-01

    Full Text Available The association constants of the complexes formed by two hosts containing pyrrole, amide and azine (pyridine and 1,8-naphthyridine groups and six guests, all monoanions (Cl−, CH3CO2−, NO3−, H2PO4−, BF4−, PF6−, have been determined using NMR titrations. The X-ray crystal structure of the host N2,N5-bis(6-methylpyridin-2-yl-3,4-diphenyl-1H-pyrrole- 2,5-dicarboxamide (1 has been solved (P21/c monoclinic space group. B3LYP/6-31G(d,p and calculations were carried out in an attempt to rationalize the trends observed in the experimental association constants.

  16. Imidazolium ionic liquid-supported sulfonic acids: Efficient and recyclable catalysts for esterification of benzoic acid

    Institute of Scientific and Technical Information of China (English)

    Yue Qin Cai; Guo Qiang Yu; Chuan Duo Liu; Yuan Yuan Xu; Wei Wang

    2012-01-01

    Several imidazolium ionic liquid (IL)-supported sulfonic acids with different anions,[C3SO3Hmim]HSO4,[C3SO3Hmim]BF4,[C3SO3Hmim]PF6,and [C3SO3Hmim]CF3SO3,were synthesized and applied as catalysts for esterification reaction of benzoic acid.The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO4- shows the best catalytic activity.Only when less [C3SO3Hmim]HSO4 (0.3 equiv.) applied,was the product obtained with high yield of 97%.Furthermore,the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.

  17. Study of 6- cyclic -perimeter hydrocarbon ruthenium complexes bearing functionalized pyridyl diketones: Isolation of complexes with 2-N∩O and 4-N∩O bonding modes of ligands

    Indian Academy of Sciences (India)

    Saphidabha L Nongbri; Babulal Das; Mohan Rao Kollipara

    2012-11-01

    Chelating mono- and di-pyridyl functionalized -diketones, viz. 1-phenyl-3-(2-pyridyl) propane-1,3-dione (pppdH) and 1,3-di(2-pyridyl)propane-1,3-dione (dppdH) ligands yielded new water soluble 6-arene ruthenium(II) complexes of the formulation [(6-arene)Ru(2-N-O-pppdH)Cl]+ (arene = C6H6 1, pPrC6H4Me 2, C6Me6 3) and [(6-arene)2Ru2(4-N-O-dppd)Cl2]+ (arene = C6H6 4, -PrC6H4Me 5, C6Me6 6), as their (complexes 1-4, 6) PF6 salt or (complex 5) BF4 salt. The complexes were obtained by treatment of respective precursors, [(6-arene)Ru(-Cl)Cl]2 (arene = C6H6, -PrC6H4Me, C6Me6) in 1:2 and 1:1 molar ratio with pppdH and dppdH in the presence of NH4PF6/NH4BF4. All the complexes have been characterized on the basis of FT-IR and NMR spectroscopic data as well as by elemental analysis. Molecular structures of representative complexes 2, 5 and 6 have been confirmed by single crystal X-ray diffraction studies. The `O-C-C-C-O' fragment of the coordinated ligand (pppdH) is neutral in complexes 1-3 and that of the dppdH ligand existed as a neutral as well as concomitantly uninegative fashion in complexes 4-6 due to the delocalization of -electrons.

  18. Non-covalent interactions in ionic liquid ion pairs and ion pair dimers: a quantum chemical calculation analysis.

    Science.gov (United States)

    Marekha, Bogdan A; Kalugin, Oleg N; Idrissi, Abdenacer

    2015-07-14

    Ionic liquids (ILs) being composed of bulky multiatomic ions reveal a plethora of non-covalent interactions which determine their microscopic structure. In order to establish the main peculiarities of these interactions in an IL-environment, we have performed quantum chemical calculations for a set of representative model molecular clusters. These calculations were coupled with advanced methods of analysis of the electron density distribution, namely, the quantum theory of atoms in molecules (QTAIM) and the non-covalent interaction (NCI; J. Am. Chem. Soc., 2010, 132, 6499) approaches. The former allows for profound quantitative characterization of non-covalent interactions between atoms while the latter gives an overview of spatial extent, delocalization, and relative strength of such interactions. The studied systems consist of 1-butyl-3-methylimidazolium (Bmim(+)) cations and different perfluorinated anions: tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)), trifluoromethanesulfonate (TfO(-)), and bis(trifluoromethanesulfonyl)imide (TFSI(-)). IL ion pairs and ion pair dimers were considered as model structures for the neat ILs and large aggregates. Weak electrostatic hydrogen bonding was found between the anions and the imidazolium ring hydrogen atoms of cations. Weaker but still appreciable hydrogen bonding was also noted for hydrogen atoms adjacent to the imidazolium ring alkyl groups of Bmim(+). The relative strength of the hydrogen bonding is higher in BmimTfO and BmimBF4 ILs than in BmimPF6 and BmimTFSI, whereas BmimTfO and BmimTFSI reveal higher sensitivity of hydrogen bonding at the different hydrogen atoms of the imidazolium ring. PMID:26059822

  19. Structural characterization and DFT study of V(IV)O(acac)2 in imidazolium ionic liquids.

    Science.gov (United States)

    Mota, Andreia; Hallett, Jason P; Kuznetsov, Maxim L; Correia, Isabel

    2011-09-01

    We report the structural characterization of vanadyl acetylacetonate in imidazolium room temperature ionic liquids--bbimNTf(2), bmimNTf(2), C(3)OmimNTf(2), bm(2)imNTf(2), bmimPF(6), bmimOTf, bmimBF(4), bmimMeCO(2), bmimMeSO(4), bmimMe(2)PO(4) and bmimN(CN)(2)--and organic solvents. The complex was characterized by visible electronic (Vis) and EPR spectroscopies. VO(acac)(2) shows solvatochromism in the selected ionic liquids and behaves as in organic solvents, evidencing coordination of the ionic liquid anion in the solvents with higher coordinating ability. The Lewis basicity order obtained for the IL anions was: PF(6)(-) < NTf(2)(-) < OTf(-)≈ MeCO(2)(-) < MeSO(4)(-) < BF(4)(-)≈ N(CN)(2)(-) < Me(2)PO(4)(-). The solvent effect on the spectroscopic data was tentatively examined using linear solvation energy relationships based on the Kamlet-Taft solvent scale (α, β and π*), however no suitable correlation was found with all data. The EPR characterization showed the presence of two isomers in bmimOTf, bmimMeCO(2) and bmimMe(2)PO(4), suggesting coordination of the ionic liquid anions in both equatorial and axial positions. The full geometry optimization of cis-/trans-VO(acac)(2)(OTf)(-) and cis-/trans-VO(acac)(2)(OTf)(mmim) structures was done at the B3P86/6-31G* level of theory. The calculations confirm that the anion OTf(-) is able to coordinate to VO(acac)(2) with the trans isomer being more stable than the cis by 4.8 kcal mol(-1). PMID:21789301

  20. Enzymatic hydrolysis of penicillin in mixed ionic liquids/water two-phase system.

    Science.gov (United States)

    Jiang, Yangyang; Xia, Hansong; Guo, Chen; Mahmood, Iram; Liu, Huizhou

    2007-01-01

    In this paper, an integrated process involving the mixed ionic liquids/water two-phase system (MILWS) is proposed to improve the efficiency for enzymatic hydrolysis of penicillin G. First, hydrophilic [C4mim]BF4 (1-butyl-3-methylimidazolium tetrafluoraborate) and NaH2PO4 salt form an ionic liquids aqueous two-phase system (ILATPS), which could extract penicillin from its fermentation broth efficiently. Second, a hydrophobic [C4mim]PF6 (1-butyl-3-methylimidazolium hexafluoraphosphate) is introduced into the ionic liquids-rich phase of ILATPS containing penicillin and converses it into MILWS. Penicillin is hydrolyzed by penicillin acylase in the water phase of MILWS at pH 5. The byproduct phenylacetic acid (PAA) is partitioned into the ionic liquids mixture phase, while the intended product 6-aminopenicillanic acid (6-APA) is precipitated at this pH. In comparison with a similar butyl acetate/water system (BAWS) at pH 4, MILWS exhibits two advantages. (1) The selectivity between PAA and penicillin is greatly optimized at pH 5 by varying the mole ratio of [C4mim]PF6/[C4mim]BF4 in MILWS, whereas in BAWS the unalterable nature of the organic solvent restricts the optimized pH for maximum selectivity between PAA and penicillin at pH 4. (2) The pH for 6-APA precipitation in BAWS is 4, whereas it shifts to pH 5 in MILWS due to the complexation between negatively charged 6-APA and the cationic surface of the ionic liquids micelle. As a result, the removal of the two products from the enzyme sphere at relatively high pH is permitted in MILWS, which is beneficial for enzymatic activity and stability in comparison with the acidic pH 4 environment in BAWS.

  1. LiODFB: A unique lithium salt for lithium ion battery%可用于锂离子电池的新型锂盐:LiODFB

    Institute of Scientific and Technical Information of China (English)

    谢辉; 唐致远; 李中延

    2007-01-01

    介绍一种新型的可用于锂离子电池的锂盐:LiODFB(lithium oxalyldifluoroborate).LiODFB独特的化学结构,使其结合了双乙二酸硼酸锂(LiBOB)及四氟硼酸锂(LiBF4)的优势.与LiBOB相比,LiODFB在碳酸酯中的溶解性和溶剂的黏度有了明显改善,从而使锂离子电池具有更好的低温性能和倍率放电性能.而与LiBF4相比,LiODFB能促进稳定固态电解液界面(solid electrolyte interface,SEI)的形成,改善了锂离子电池的高温性能.该种新型锂盐还具有以下优点:与金属锂的化学稳定性好,在高电位下能够很好地使铝箔得到钝化和提高锂离子电池安全性能及抗过充的能力.这些性能使得LiODFB成为一种极有可能替代LiPF6的新型锂盐.

  2. Application of a group contribution equation of state for the thermodynamic modeling of binary systems (gas + ionic liquids) with bis[(trifluoromethyl)sulfonyl]imide anion

    International Nuclear Information System (INIS)

    The properties of ionic liquids (ILs) can be modified by appropriate selection of cations and anions. Even if an infinite number of ionic liquids can be generated, only a limited number of families of anions and cations are used. The group contribution equation of state (GC-EoS) is a promising method for calculating the phase behavior of systems with ILs. If the parameters of the characteristic functional group of a IL family are fitted by using data of a reduced number of ILs of the family, then the phase behavior of all the ILs of the same family can be predicted using exclusively the data of the pure components. Previously, the parameters of the IL families with an imidazolium-based cation and the anions PF6, BF4NO3, and Tf2N were fitted to experimental data , and some ternary systems (CO2 + organics + ionic liquid [bmim][BF4]) were also modeled . In this work, the GC-EoS was used to calculate phase behavior of gases {(CO2, O2, or SO2) + ionic liquids} with Tf2N anion and cations of the families 2,3-dimethyl-imidazolium, 1-alkyl-1-methyl-pyrrolidinium, and 1-alkyl-3-methyl-pyridinium. The GC-EoS was able to reproduce experimental data with deviations of the same order of experimental uncertainty. With the correlated parameters it will be possible to predict the phase behavior of systems with ILs of the families considered in this work.

  3. Combined main-chain/side-chain ionic liquid crystalline polymer based on ‘jacketing’ effect: Design, synthesis, supra-molecular self-assembly and photophysical properties

    Directory of Open Access Journals (Sweden)

    L. Weng

    2015-06-01

    Full Text Available Reasonably fabricating ordered structures of ionic polymers is very important for the development of novel functional materials. By combining the ions and liquid cry stalline polymer, we successfully designed and synthesized a series of novel combined main-chain/side-chain ionic liquid crystalline polymer (MCSC-ILCPs containing imidazolium groups and different counter-anions, poly (2,5-bis{[6-(4-butoxy-4'-imidazolium biphenylhexyl]oxycarbonyl}styrene salts poly(BImBHCS-X with the following types of counter-anions (Br¯, BF4¯, PF6¯ and TFSI¯. Combined technologies confirmed the chemical structures of the monomers and polymers with imidazolium cation and different counter-anions. Differential scanning calorimetry (DSC, polarized light microscopy (PLM and one- and two-dimensional wide-angle X-ray diffraction (1D and 2D WAXD results illustrated that the LC structures and the transitions of ordered structures depended on the nature of the counter-anion employed. The polymers with Br¯ and BF4¯ counter-anions exhibited smectic A (SmA LC behavior below the isotropic temperature. The another one, poly(BImBHCS–TFSI with the large volume of the TFSI¯ anion destroyed the packing of the LC ordered structure resulting in an amorphous structure. The photophysical properties of the polymers prepared can be adjusted by tuning the ionic interaction of the polymers by switching the counter-anion.

  4. 5 and 6 - cyclic -perimeter hydrocarbon platinum group metal complexes of 3-(2-pyridyl)pyrazole derived ligands with a pendant nitrile group: Syntheses, spectral and structural studies

    Indian Academy of Sciences (India)

    Gloria Sairem; Venkateswara Rao Anna; Peng Wang; Bbulal Das; Mohan Rao Kollipara

    2012-03-01

    Reaction of two equivalents 4-{(3-(pyridine-2-yl) 1H-pyrazole-1-yl}methyl benzonitrile (L1) and 3-{(3-(pyridine-2-yl)1H-pyrazole-1-yl}methyl benzonitrile (L2) with one equivalent of [(6-arene)Ru(- Cl)Cl]2 and [Cp∗M(-Cl)Cl]2 in methanol yielded mononuclear complexes of the formulae [(6-arene)Ru(L1/L2)Cl]BF4{arene =C6H6 (1, 6); C10H14 (2, 7); C6Me6 (3, 8)} and [Cp∗M(L1/L2)Cl]PF6/BF4 {Cp∗= 5-C5Me5, M=Rh (4, 8); Ir (5, 10)}. These complexes are characterized by IR, 1H NMR and identities of the structure are established by single crystal XRD studies of some of the representative complexes. It is confirmed from the spectral studies that the nitrile group is not taking part in complexation; instead it remains as a free pendant group only.

  5. Distribution of 1-alkyl-3-methylimidazolium ions and their ion pairs between dichloromethane and water.

    Science.gov (United States)

    Katsuta, Shoichi; Yamaguchi, Naoko; Ogawa, Ryuji; Kudo, Yoshihiro; Takeda, Yasuyuki

    2008-10-01

    The distribution behavior of the salts of a series of 1-alkyl-3-methylimidazolium cations (RMeIm(+); R = butyl, hexyl, and octyl) with tetrafluoroborate (BF(4)(-)), hexafluorophosphate (PF(6)(-)), bis(trifluoromethanesulfonyl)amide (NTf(2)(-)), and 2,4,6-trinitrophenolate (Pic(-)) anions has been investigated in a dichloromethane-water system at 25 degrees C. The distribution constants (K(D)) of the ion pairs and the transfer activity coefficients ((o)gamma(w)) of the single ions were determined. For the ion pairs with a given anion, the log K(D) value increases linearly with the number of methylene groups (N(CH2)) in the cation, which can be explained by using the regular solution theory. A similar relationship was observed between log (o)gamma(w) and N(CH2) for the free RMeIm(+) ions, and the result was discussed by decomposing the transfer activity coefficient into the Born-type electrostatic contribution and the non-electrostatic one. For the free anions and their ion pairs with a given cation, the (o)gamma(w) and K(D) values increase with increasing molar volume of the anion: i.e., BF(4)(-) ion-pair formation in water are also discussed by comparing the present results with those of tetraalkylammonium salts previously reported.

  6. DFT study of the energetic and noncovalent interactions between imidazolium ionic liquids and hydrofluoric acid.

    Science.gov (United States)

    Velarde, Marco V; Gallo, Marco; Alonso, P A; Miranda, A D; Dominguez, J M

    2015-04-16

    In this work, we evaluated the energetic interactions between imidazolium ionic liquids (ILs) and hydrofluoric acid, as well as the cation-anion interactions in ILs. We used DFT calculations that include dispersion corrections employing the PBE and M06 functionals. We tested 22 ILs, including [C4MIM][PF6], [C4MIM][NTf2], and [C4MIM][CH3COO], obtaining interaction energies in the range of -27 to -13 kcal/mol with the PBE functional. The NCI (noncovalent interaction) index developed by Yang and collaborators ( J. Am. Chem. Soc. 2010 , 132 , 6498 - 6506 ; J. Chem. Theory Comput. 2011 , 7 , 625 - 632 ) also was used for mapping the key noncovalent interactions (hydrogen bonds, van der Waals, and steric repulsions) between the anions and cations of ILs and also for interactions of ILs with hydrofluoric acid (HF). The results obtained show that the anions have a stronger effect with respect to cations in their capacity for interacting with hydrofluoric acid, and the strongest interaction energies occur in systems where the key noncovalent interactions are mainly hydrogen bonds. The [C4MIM][PF6], [C4MIM][NTf2], and [C4MIM][BF4] ionic liquids displayed the weakest cation-anion interactions.

  7. Translational diffusion in mixtures of imidazolium ILs with polar aprotic molecular solvents.

    Science.gov (United States)

    Marekha, Bogdan A; Kalugin, Oleg N; Bria, Marc; Buchner, Richard; Idrissi, Abdenacer

    2014-05-22

    Self-diffusion coefficients of cations and solvent molecules were determined with (1)H NMR in mixtures of 1-n-butyl-3-methylimidazolium (Bmim(+)) tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)), trifluoromethanesulfonate (TfO(-)), and bis(trifluoromethylsulfonyl)imide (TFSI(-)) with acetonitrile (AN), γ-butyrolactone (γ-BL), and propylene carbonate (PC) over the entire composition range at 300 K. The relative diffusivities of solvent molecules to cations as a function of concentration were found to depend on the solvent but not on the anion (i.e., IL). In all cases the values exhibit a plateau at low IL content (x(IL) < 0.2) and then increase steeply (AN), moderately (γ-BL), or negligibly (PC) at higher IL concentrations. This behavior was related to the different solvation patterns in the employed solvents. In BmimPF6-based systems, anionic diffusivities were followed via (31)P nuclei and found to be higher than the corresponding cation values in IL-poor systems and lower in the IL-rich region. The inversion point of relative ionic diffusivities was found around equimolar composition and does not depend on the solvent. At this point, a distinct change in the ion-diffusion mechanism appears to take place. PMID:24792375

  8. Transition metal complexes supported by a neutral tetraamine ligand containing N,N-dimethylaniline units.

    Science.gov (United States)

    Chu, Lei; Hardcastle, Kenneth I; MacBeth, Cora E

    2010-08-16

    First-row transition metal-halide complexes of tris(2-dimethylaminophenyl)amine, L(Me), have been synthesized and characterized. X-ray crystallographic studies on [Co(L(Me))Br]BPh(4), [Ni(L(Me))Cl]BPh(4), [Fe(L(Me))Cl]BPh(4), and [Cu(L(Me))Cl]BF(4) have been performed, and in all cases the ligand produces five-coordinate complexes with distorted trigonal bipyramidal coordination geometries. Where possible, comparisons have been made to the structures of related neutral tripodal ligands. Spectroscopic and magnetic studies of these complexes are also described. The Cu(I)-carbonyl complexes [Cu(L(Me))(CO)]PF(6) and [Cu(Me(6)tren)(CO)]PF(6) (Me(6)tren = tris(N,N-dimethylaminoethyl)amine) have also been prepared. Infrared spectroscopic investigations of these carbonyl complexes confirm that L(Me) is a less electron donating ligand than Me(6)tren and indicate that L(Me) can impart a different coordination number in the solid-state.

  9. Electrochemical and impedance investigation of the effect of lithium malonate on the performance of natural graphite electrodes in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiao-Guang [ORNL; Dai, Sheng [ORNL

    2010-01-01

    Lithium malonate (LM) was coated on the surface of a natural graphite (NG) electrode, which was then tested as the negative electrode in the electrolytes of 0.9 M LiPF6/EC-PC-DMC (1/1/3, by weight) and 1.0 M LiBF4/EC-PC-DMC (1/1/3, by weight) under a current density of 0.075 mA cm-2. LM was also used as an additive to the electrolyte of 1.0 M LiPF6/EC-DMC-DEC (1/1/1, by volume) and tested on a bare graphite electrode. It was found that both the surface coating and the additive approach were effective in improving first charge discharge capacity and coulomb efficiency. Electrochemical impedance spectra showed that the decreased interfacial impedance was coupled with improved coulomb efficiency of the cells using coated graphite electrodes. Cyclic voltammograms (CVs) on fresh bare and coated natural graphite electrodes confirmed that all the improvement in the half-cell performance was due to the suppression of the solvent decomposition through the surface modification with LM. The CV data also showed that the carbonate electrolyte with LM as the additive was not stable against oxidation, which resulted in lower capacity of the full cell with commercial graphite and LiCoO2 electrodes.

  10. Dinuclear metal(ii)-acetato complexes based on bicompartmental 4-chlorophenolate: syntheses, structures, magnetic properties, DNA interactions and phosphodiester hydrolysis.

    Science.gov (United States)

    Massoud, Salah S; Ledet, Catherine C; Junk, Thomas; Bosch, Simone; Comba, Peter; Herchel, Radovan; Hošek, Jan; Trávníček, Zdeněk; Fischer, Roland C; Mautner, Franz A

    2016-08-01

    A series of dinuclear metal(ii)-acetato complexes: [Ni2(μ-L(Cl)O)(μ2-OAc)2](PF6)·3H2O (1), [Ni2(μ-L(Cl)O)(μ2-OAc)2](ClO4)·CH3COCH3 (2), [Cu2(μ-L(Cl)O)(μ2-OAc)(ClO4)](ClO4) (3), [Cu2(μ-L(Cl)O)(OAc)2](PF6)·H2O (4), [Zn2(μ-L(Cl)O)(μ2-OAc)2](PF6) (5) and [Mn2(L(Cl)-O)(μ2-OAc)2](ClO4)·H2O (6), where L(Cl)O(-) = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-chlorophenolate, were synthesized. The complexes were structurally characterized by spectroscopic techniques and single crystal X-ray crystallography. Six-coordinate geometries with doubly bridged acetato ligands were found in Ni(ii), Zn(ii) and Mn(ii) complexes 1, 2, 5 and 6, whereas with Cu(ii) complexes a five-coordinate species was obtained with 4, and mixed five- and six-coordinate geometries with a doubly bridged dimetal core were observed in 3. The magnetic properties of complexes 1-4 and 6 were studied at variable temperatures and revealed weak to very weak antiferromagnetic interactions in 1, 2, 4 and 6 (J = -0.55 to -9.4 cm(-1)) and ferromagnetic coupling in 3 (J = 15.4 cm(-1)). These results are consistent with DFT calculations performed at the B3LYP/def2-TZVP(-f) level of theory. Under physiological conditions, the interaction of the dinculear complexes 1-5 with supercoiled plasmid ds-DNA did not show any pronounced nuclease activity, but Ni(ii) complexes 1 and 2 revealed a strong ability to unwind the supercoiled conformation of ds-DNA. The mechanistic studies performed on the interaction of the Ni(ii) complexes with DNA demonstrated the important impact of the nickel(ii) ion in the unwinding process. In combination with the DNA study, the phosphatase activity of complexes 1, 3, and 5 was examined by the phosphodiester hydrolysis of bis(2,4-dinitrophenol)phosphate (BDNPP) in the pH range of 5.5-10.5 at 25 °C. The Michaelis-Menten kinetics performed at pH 7 and 10.7 showed that catalytic efficiencies kcat/KM (kcat = catalytic rate constant, KM = substrate binding constant) decrease in the order

  11. Structures that should be Described in Higher-Symmetry,Centrosymmetric Space Groups. Part 2. The Structures of[Ni(C5H4NO-2-CH=N-CH2CH2-N = CH-2-C5H4NO)(H2O)2](ClO4)2,{Ni[C5H4NO-2-CH = N-CH(CH3)CH2-N = CH-2-C5H4NO](H2O)2}(ClO4)2,{Cu[(C5H4NO-2-CH = N-N = C

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The space groups of the transition metal-Schiff base complexes, [ Ni scribed in Cc), have been revised to C2/c. The general descriptions of the first two structures are unchanged in the higher-symmetry setting; for the last structure, the copper atom is re-assigned an octahedral coordination geometry instead of the reported square-pyramidal coordination geometry. The space group of Atomic coordinates for the revised structures are reported.

  12. Silver(I) complexes with phthalazine and quinazoline as effective agents against pathogenic Pseudomonas aeruginosa strains.

    Science.gov (United States)

    Glišić, Biljana Đ; Senerovic, Lidija; Comba, Peter; Wadepohl, Hubert; Veselinovic, Aleksandar; Milivojevic, Dusan R; Djuran, Miloš I; Nikodinovic-Runic, Jasmina

    2016-02-01

    Five silver(I) complexes with aromatic nitrogen-containing heterocycles, phthalazine (phtz) and quinazoline (qz), were synthesized, characterized and analyzed by single-crystal X-ray diffraction analysis. Although different AgX salts reacted with phtz, only dinuclear silver(I) complexes of the general formula {[Ag(X-O)(phtz-N)]2(μ-phtz-N,N')2} were formed, X=NO3(-) (1), CF3SO3(-) (2) and ClO4(-) (3). However, reactions of qz with an equimolar amount of AgCF3SO3 and AgBF4 resulted in the formation of polynuclear complexes, {[Ag(CF3SO3-O)(qz-N)]2}n (4) and {[Ag(qz-N)][BF4]}n (5). Complexes 1-5 were evaluated by in vitro antimicrobial studies against a panel of microbial strains that lead to many skin and soft tissue, respiratory, wound and nosocomial infections. The obtained results indicate that all tested silver(I) complexes have good antibacterial activity with MIC (minimum inhibitory concentration) values in the range from 2.9 to 48.0μM against the investigated strains. Among the investigated strains, these complexes were particularly efficient against pathogenic Pseudomonas aeruginosa (MIC=2.9-29μM) and had a marked ability to disrupt clinically relevant biofilms of strains with high inherent resistance to antibiotics. On the other hand, their activity against the fungus Candida albicans was moderate. In order to determine the therapeutic potential of silver(I) complexes 1-5, their antiproliferative effect on the human lung fibroblastic cell line MRC5, has been also evaluated. The binding of complexes 1-5 to the genomic DNA of P. aeruginosa was demonstrated by gel electrophoresis techniques and well supported by molecular docking into the DNA minor groove. All investigated complexes showed an improved cytotoxicity profile in comparison to the clinically used AgNO3.

  13. Preparation and Crystal Structures of Silver(I), Mercury(II), and Lead(II) Complexes of Oxathia-Tribenzo-Macrocycles

    International Nuclear Information System (INIS)

    An investigation of the coordination behavior of sulfur-containing mixed-donor tribenzo-macrocycles L1-L3 (L1: 20-membered O3S2, L2: 20-membered O2S3, and L3: 23-membered O4S2) with d10-metal (Ag+, Hg2+, and Pb2+) salts is reported. The X-ray structures of five complexes (1-5) with different structural types and stoichiometries, including mono- to dinuclear species have been determined. Reactions of L2 and L3 with the silver(I) salts (PF6- and SCN-) afforded two dinuclear 2:2 (metal-to-ligand) complexes with different arrangements: a sandwich-type cyclic dinuclear complex [Ag2(L2)2](PF6)2·3CH2Cl2 (1) and a linear dinuclear complex [Ag2(L3)2(SCN)2] (2), in which two monosilver(I) complex units are linked by an Ag-Ag contact. Reactions of L1 and L2 with mercury(II) salts (SCN- and Cl-) gave a mononuclear 1:1 complexes [Hg(L1)(SCN)2] (3) and [Hg(L2)Cl2] (4) with anion coordination in both cases. L2 reacts with lead(II) perchlorate to yield a mononuclear sandwich-type complex [Pb(L2)2(ClO4)2] (5), giving an overall metal coordination geometry of eight with a square antiprism arrangement. From these results, the effects of the donor variation and the anion-coordination ability on the resulting topologies of the soft metal complexes are discussed

  14. Extraction of lithium from salt lake brine using room temperature ionic liquid in tributyl phosphate

    International Nuclear Information System (INIS)

    Highlights: • We proposed a new system for Li recovery from salt lake brine by extraction using an ionic liquid. • Cation exchange was proposed to be the mechanism of extraction followed in ionic liquid. • This ionic liquid system shown considerable extraction ability for lithium and the single extraction efficiency of lithium reached 87.28% under the optimal conditions. - Abstract: Lithium is known as the energy metal and it is a key raw material for preparing lithium isotopes which have important applications in nuclear energy source. In this work, a typical room temperature ionic liquid (RTILs), 1-butyl-3-methyl-imidazolium hexafluorophosphate ([C4mim][PF6]), was used as an alternative solvent to study liquid/liquid extraction of lithium from salt lake brine. In this system, the ionic liquid, NaClO4 and tributyl phosphate (TBP) were used as extraction medium, co-extraction reagent and extractant respectively. The effects of solution pH value, phase ratio, ClO4− amount and other factors on lithium extraction efficiency had been investigated. Optimal extraction conditions of this system include the ratio of TBP/IL at 4/1 (v/v), O/A at 2:1, n(ClO4−)/n(Li+) at 2:1, the equilibration time of 10 min and unadjusted pH. Under the optimal conditions, the single extraction efficiency of lithium was 87.28% which was much higher than the conventional extraction system. Total extraction efficiency of 99.12% was obtained by triple-stage countercurrent extraction. Study on the mechanism revealed that the use of ionic liquid increased the extraction yield of lithium through cation exchange in this system. Preliminary results indicated that the use of [C4mim][PF6] as an alternate solvent to replace traditional organic solvents (VOCs) in liquid/liquid extraction was very promising

  15. 共萃剂ClO4-作用下磷酸三丁酯分离盐湖卤水锂镁%Lithium and Magnesium Separation from Salt Lake Brine by Tributyl Phosphate under Action of Co-extraction Reagent ClO4-

    Institute of Scientific and Technical Information of China (English)

    杨立新; 邬赛祥; 刘肖丽; 何靖; 陈文光

    2013-01-01

    采用磷酸三丁酯(TBP)作为萃取剂、NaClO4作为共萃剂从高镁锂比盐湖卤水中提取锂,考察了萃取温度、溶液pH值、相比和ClO4-用量等因素对Li+萃取率的影响.结果表明,卤水一次萃取的最佳操作条件为:萃取时间10 min,温度25℃,Vo/Vw=2.0,n(ClO4) /n(Li+)=2.0,pH=5~8,Li+和Mg2+的最高萃取率分别为65.41%和13.31%,锂镁分离系数达到12.32.用水在Vw/Vo=1.0、50℃时进行反相萃取,Li+的反萃率达到81.52%,此时镁锂质量比由45.61下降至8.45.锂镁离子萃取过程呈放热效应,金属离子的萃入对TBP中H的化学位移没有影响,但会导致P=O双键的红外伸缩振动吸收峰从1280 cm-1移至1264 cm-1.25℃时用斜率法测定K+萃合物的组成接近2LiClO4·5TBP,反萃液经深度除镁后可制备碳酸锂.%Aiming at salt lake brine with a high ratio of magnesium/lithium, extracting lithium was researched via the extractant tributyl phosphate ( TBP) as well as the co-extraction reagent NaC104, and the effects of temperature, solution pH value, phase ratio, CIO-4 amount and other factors on Li+ extraction rate have been investigated in detail. The optimum operating conditions of a single extraction from brine are the following: the extraction time of 10 min, temperature of 25 ℃, Vo/Vw=2.0, n(C1O-4)/n(Ii+)= 2.0 and pH value in a range of 5—8. Under these conditions, the highest extraction rate for Li+ and Mg2+ was 65.41% and 13. 31% , respectively, and the Li/Mg separation coefficient reached 12. 32. Reversed phase extraction was carried out with water in Vw/V0 = 1.0 and 50℃ , the stripping rate of Li+ reached 81. 52% , and the mass ratio of Mg/Ii decreased from 45. 61 to 8.45. The extraction process of Li+ and Mg2+ presented exothermic effect, metal ions extracted into the organic phase had no effect on the chemical shifts of H in TBP, but made the IR stretching vibration frequencies of P =O double bond shift to 1264 cm-1 from 1280 cm-1. The composition of extracted complex of Li+ was close to 2LiClO4 ? 5 TBP determined by the slope method at 25 ℃ and Li2CO3 was prepared by the strip liquor after demagnesium deeply.

  16. A mixed Ni(II) ionic complex containing V-shaped water trimer: Synthesis, spectral, structural and thermal properties of {[Ni(2,2′-bpy)3][Ni(2-cpida)(2,2′ -bpy)]} (ClO4).3H2O

    Indian Academy of Sciences (India)

    Nallasamy Palanisami; Kabali Senthilkumar; Mohan Gopalakrishnan; Il-Shik Moon

    2015-05-01

    A mixed Ni(II) ionic complex of {[Ni(2,2′-bpy)3][Ni(2-cpida)(2,2′-bpy)]}(ClO4).3H2O (1) (2-H3cpida = N-(2-carboxyphenyl)iminodiacetic acid, 2,2′-bpy = 2,2′-bipyridyl) has been synthesized and characterized by infrared, ultraviolet and fluorescence spectroscopy, elemental and thermogravimetric analysis. The molecular structure of compound 1, as determined by single-crystal X-ray diffraction studies, showed all the three carboxylate groups are in monodendate mode. Compound 1 consists of a discrete mononuclear [Ni(2,2′-bpy)3]2+ cation, a [Ni(2-cpida)(2,2′-bpy)]− anion, a ClO$^{−}_{4}$ anion and three lattice water molecules. The H-bonding interaction between three lattice water molecule forms a V-shaped trimer (H2O)3 which gives rise to a 1-D polymeric structure in the solid state.

  17. Synthesis and structural characterization of anion complexes with azacalix[2]dipyrrolylmethane: effect of anion charge on the conformation of the macrocycle.

    Science.gov (United States)

    Guchhait, Tapas; Mani, Ganesan; Schulzke, Carola

    2016-08-01

    Tetrahomodiazacalix[2]dipyrrolylmethane 1, [-CH2(C4H3N)CR2(C4H3N)CH2N(Me)-]2 an expanded version of the calix[4]pyrrole system, has the tendency to change its ring conformation (1,3-alternate) upon anion binding analogous to calix[4]pyrrole. However, owing to its tertiary amine nitrogen atoms in the ring, it can be protonated and becomes a powerful cationic receptor for anions, besides its inherent hydrogen bonding features. Macrocycle 1 binds with a series of monoanions BF4(-), Cl(-), PhCOO(-) and ClO4(-), and their X-ray structures showed that the ring conformation constitutes the 1,2-alternate form. Upon binding with dianions SO4(2-), CrO4(2-), SiF6(2-) and S2O3(2-), the ring conformation changes to the cone conformation. The intermediate partial cone conformation results for complexes with NO3(-) and Cr2O7(2-) ions. The change in the orientation of the pyrrole NH groups depending on the charge of the anion demonstrates the flexibility of the macrocycle and the dicationic macrocycle stabilizes the anions via both hydrogen bonding and electrostatic interactions. PMID:27356484

  18. Hydrogen Bonding and Multiphonon Structure in One- and Two-Dimensional Polymeric Magnets

    Science.gov (United States)

    Musfeldt, J. L.; Brown, S.; Cao, J.; Conner, M. M.; McConnell, A. C.; Southerland, H. I.; Manson, J. L.; Schlueter, J. A.; Phillips, M. D.; Turnbull, M. M.; Landee, C. P.

    2007-03-01

    We report a systematic investigation of the temperature dependent infrared vibrational spectra of a family of chemically related coordination polymeric magnets based upon two different bridging anions, fluoride (F^-) and bifluoride (HF2^-), in copper-pyrazine complexes including Cu(HF2)(pyz)2BF4, Cu(HF2)(pyz)2ClO4, and CuF2(H2O)(pyz)). We compare our results with several one- and two-dimensional prototype materials including Cu(NO3)2(pyz) and Cu(ClO4)(pyz) 2. Unusual low temperature hydrogen bonding, local structural transitions associated with stronger low-temperature hydrogen bonding, and striking multiphonon effects that derive from coupling of an infrared-active fundamental with strong Raman-active modes of the pyrazine building-block molecule are observed. Based on the spectroscopic evidence, these interactions are common to this family of coordination polymers and work to stabilize the low temperature magnetic state. Similar interactions are likely to be present in other molecule-based magnets.

  19. Spectroscopic studies on the inhibitory effects of ionic liquids on lipase activity

    Science.gov (United States)

    Fan, Yunchang; Dong, Xing; Li, Xiaojing; Zhong, Yingying; Kong, Jichuan; Hua, Shaofeng; Miao, Juan; Li, Yan

    2016-04-01

    The effects of ionic liquids (ILs) on the lipase activity were studied by UV-Vis spectroscopy and the IL-lipase interaction mechanism at the molecular level was investigated by fluorescence technique. Experimental results indicated that the lipase activity was inhibited by ILs and the degree of inhibition highly depended on the chemical structures of ILs. The inhibitory ability of the Cl-- and Br--based ILs increased with increasing the alkyl chain length in the IL cation. Thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were obtained by analyzing the fluorescence behavior of lipase with the addition of ILs. Both ΔH and ΔS were positive suggesting hydrophobicity was the major driven force for the Cl-- and Br--based ILs. For the BF4--, CF3SO3--, ClO4-- and N(CN)2--based ILs, hydrogen bonding was the main driven force. For a more comprehensive understanding of the effects of ILs on lipase activity, the roles of hydrophobicity and hydrogen bonding must be considered simultaneously. A regression-based equation was developed to describe the relationship of the inhibitory ability of ILs and their hydrophobicity and hydrogen bonding ability.

  20. Comparison of Magnetic Field-Modified Electronic Excitations in Ni(II) Compounds

    Science.gov (United States)

    Long, Virginia; Schundler, E. C.; Makumbe, P. O.; Wei, X.; Landry, B. R.; Maxcy, K. R.; Turnbull, M. M.; Landee, C. P.

    2006-03-01

    NTDN (Ni[tn]2[NO2]2) can be considered a paramagnetic analog material to the Haldane compounds NENP and NENB (Ni[en]2NO2ClO4 and Ni[en]2NO2BF4; where en = C2N2H8 and tn = C2N3H10). Except for the different bonding of one NO2 group and the absence or presence of spin chains, NTDN and the Haldane compounds have nearly identical electronic coordination around the Ni^2+ ions. Here, we report and compare the magnetic field (H)-dependent polarized optical transmittance of the three materials in the range 9,000 to 22,000 cm-1. The H dependence is manifest in the varying intensities of certain electronic absorptions with applied field. Although all three materials possess similar H- sensitive excitations, the details of the H dependence differ with the magnetic ground states. In NTDN, the intensity changes commence at H = 0 and saturate at 10 T, whereas in the Haldane compounds, the onset of changes is at the gap- closing critical field, HC, above which the intensity is linearly modified with field. The mechanism of the H- dependence is yet to be clarified and probably depends on the nature of the electronic excitation. Intensity variations with applied field are observed in both Ni^2+-to-NO2^- charge transfer transitions and Ni^2+ d-d spin forbidden excitations.

  1. Stretchable Self-Healing Polymeric Dielectrics Cross-Linked Through Metal-Ligand Coordination.

    Science.gov (United States)

    Rao, Ying-Li; Chortos, Alex; Pfattner, Raphael; Lissel, Franziska; Chiu, Yu-Cheng; Feig, Vivian; Xu, Jie; Kurosawa, Tadanori; Gu, Xiaodan; Wang, Chao; He, Mingqian; Chung, Jong Won; Bao, Zhenan

    2016-05-11

    A self-healing dielectric elastomer is achieved by the incorporation of metal-ligand coordination as cross-linking sites in nonpolar polydimethylsiloxane (PDMS) polymers. The ligand is 2,2'-bipyridine-5,5'-dicarboxylic amide, while the metal salts investigated here are Fe(2+) and Zn(2+) with various counteranions. The kinetically labile coordination between Zn(2+) and bipyridine endows the polymer fast self-healing ability at ambient condition. When integrated into organic field-effect transistors (OFETs) as gate dielectrics, transistors with FeCl2 and ZnCl2 salts cross-linked PDMS exhibited increased dielectric constants compared to PDMS and demonstrated hysteresis-free transfer characteristics, owing to the low ion conductivity in PDMS and the strong columbic interaction between metal cations and the small Cl(-) anions which can prevent mobile anions drifting under gate bias. Fully stretchable transistors with FeCl2-PDMS dielectrics were fabricated and exhibited ideal transfer characteristics. The gate leakage current remained low even after 1000 cycles at 100% strain. The mechanical robustness and stable electrical performance proved its suitability for applications in stretchable electronics. On the other hand, transistors with gate dielectrics containing large-sized anions (BF4(-), ClO4(-), CF3SO3(-)) displayed prominent hysteresis due to mobile anions drifting under gate bias voltage. This work provides insights on future design of self-healing stretchable dielectric materials based on metal-ligand cross-linked polymers. PMID:27099162

  2. Synthesis and structures of ligand-dominated one-dimensional silver(I)-bis(pyridylmethyl)amine coordination chains

    Science.gov (United States)

    Lin, Hung-Jui; Liu, Yu-Chiao; Tseng, Yu-Jui; Wu, Jing-Yun

    2016-10-01

    Reactants slow diffusion of Ag(I) salts with 3,4‧-bis(pyridylmethyl)amine (3,4‧-bpma), an unsymmetric bis-pyridyl ligand equipped with a non-innocent amine backbone, afforded polymeric coordination adducts 1-5 having a general formula {[Ag(3,4‧-bpma)(solv)]X}n (solv = H2O, CH3OH, and none; X= CF3CO2-, BF4-, ClO4-, CF3SO3-, and SbF6-). Single-crystal X-ray diffraction (SCXRD) analyses reveal that colorless crystals of Ag(I) coordination polymers (CPs) 1-5 have very similar one-dimensional (1D) non-flat chain structures, which are preferentially depicted as a "zipper-like" rather than a ladder-like or a double-stranded chain topologies. The 3,4‧-bpma ligand in these Ag(I) CPs displays a μ3-bridging mode with a gauche-trans (1,4, and 5) and a trans-trans (2 and 3) conformations. Noteworthy, anions do not show strong influence on structural modulation of Ag(I) CPs in the solid state, but really affect CP conformations and packing fashions, indicative of a ligand-dominated assembly process for such a Ag(I)-3,4‧-bpma system. Thermal stabilities and solid-state photoluminescence properties of crystalline materials 1-5 were investigated.

  3. Highly porous lithium-ion conducting solvent-free poly(vinylidene fluoride-co-hexafluoropropylene)/poly(ethyl methacrylate) based polymer blend electrolytes for Li battery applications

    International Nuclear Information System (INIS)

    Plasticised polymer blend electrolytes based on poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP) and poly(ethyl methacrylate) (PEMA) were prepared for different lithium salts LiX (X = ClO4, CF3SO3, BF4 and N[CF3SO2]2) using facile solution casting. To confirm the structures and complexations of the electrolyte films, the prepared electrolytes were subjected to XRD and FTIR analysis. TG–DTA was used to ascertain the thermal stability of the electrolytes, and the porous nature of the electrolytes was identified using scanning electron microscopy via ion-hopping conduction. AC impedance analysis was performed for all the electrolyte samples at various temperatures from 303 to 363 K. The results suggest that among the various lithium salts, LiN[CF3SO2]2-based electrolytes exhibited the highest ionic conductivity (0.918 × 10−3 S cm−1). The temperature dependence of the ionic conductivity also complies with the VTF relation

  4. Detoxification of lignocellulosic prehydrolyzate using imidazolium-based ionic liquid%咪唑类离子液体对木质纤维预水解液的脱毒

    Institute of Scientific and Technical Information of China (English)

    杨金龙; 荣亚运; 高露; 朱均均; 徐勇; 勇强; 欧阳嘉; 余世袁

    2016-01-01

    Aiming at the effect of inhibitors on yeast ethanol fermentation during the fuel ethanol biorefinery process, a new green detoxification technology-ionic liquid extraction was developed for detoxification of the prehydrolyzate obtained from washed acid-catalyzed steam-exploded corn stover (ASC). The extractive performances of two kinds of imidazolium-based ionic liquids (alkylimidazolium hexafluorophosphate [Cnmim][PF6](n=4,6,8) and alkylimidazolium tetrafluoroborate [Cnmim][BF4](n=6,8)) for the ASC prehydrolyzate were investigated and compared. The results indicated that the extraction efficiency of the inhibitors decreased with the increase of alkyl chain length on the cation of ionic liquids. Ionic liquid with4BF− anion had much higher extraction efficiency for the inhibitors than those with6PF− anion because of the stronger effective charge in4BF−. Compared to the extraction efficiency of sugars and inhibitors, [C8mim][BF4] was selected as the extractant for detoxification of the ASC prehydrolyzate. Its detoxification results indicated that 85.13% of 5-hydroxymethylfurfural, 53.22% of formic acid, 47.53% of acetic acid and 65.05% of total phenols could be removed, while the loss of sugars was less than 6%.%针对燃料乙醇生物炼制过程中抑制物对酵母乙醇发酵的抑制作用,以水洗稀酸蒸汽爆破预处理玉米秸秆得到的预水解液为研究对象,采用新型绿色脱毒技术——离子液体进行萃取脱毒,研究比较了两种咪唑类离子液体[烷基咪唑六氟磷酸盐离子液体[Cnmim][PF6](n=4,6,8)和烷基咪唑四氟硼酸盐离子液体[Cnmim][BF4](n=6,8)]对预水解液的萃取性能。结果表明,随着咪唑类离子液体阳离子烷基链长度的增加,离子液体对抑制物的萃取性能下降,具有更强电负性的阴离子为4BF−的离子液体比阴离子为6PF−的离子液体萃取效率更高。通过比较糖与抑制物的萃取率,最终选择[C8mim][BF4]作为

  5. Contribution to the characterization of room temperature ionic liquids under ionizing irradiation

    International Nuclear Information System (INIS)

    Room-Temperature Ionic Liquids are potentially interesting for nuclear fuel treatment. Within this framework, ionic liquids stability towards ionizing radiations (α, β or γ) is determining their potential application. The aim of this work is to assess a better understanding of ionic liquids behaviour under radiolysis. Ionic liquids chosen in these studies are constituted with BuMeIm+ (or Bu3MeN+) cation associated with various anions: Tf2N-, TfO-, PF6- and BF4-. Moreover, development of suitable chemical analysis tools crucial for characterization of these compounds has been realized. Ionic liquids stability has been mainly studied under γ irradiation, but also under electron beam or heavy particles irradiations. Ionic liquids degradation under radiolysis has been determined with two complementary approaches. The first one aims at understanding radio-induced degradation mechanisms with radical species analysis by Electron Paramagnetic Resonance spectroscopy (EPR). The second one aims at characterizing stable radiolysis products formed in liquid and gaseous phases. Studies were conducted with several analytical techniques: Electro Spray Ionisation Mass Spectrometry (ESI-MS), High Pressure Liquid Chromatography (HPLC, HPLC/UV-VIS, HPLC/ESI-MS), Gas Analysis Mass Spectrometry (Gas MS) and Gas Chromatography hyphenated with Mass Spectrometry (GC/MS). Firstly, the ionic liquid [Bu3MeIm][Tf2N] has been studied under γ irradiation. Radiolytic stability has been quantitatively assessed for high doses of radiations and a proposal of degradation scheme has been proposed on the basis of radio-induced radicals and radiolysis products analysis. Those data have been compared to those obtained for the γ radiolysis of the ionic liquid [Bu3MeN][Tf2N], enabling to assess cation influence on ionic liquids radiolysis. Secondly, degradation under γ irradiation of ionic liquids [BuMeIm][X] (X- Tf2N-, TfO-, PF6-, BF4-) has been quantitatively and qualitatively compared. Those data

  6. Ionic Liquids Assisted Synthesis of ZnO Nanostructures: Controlled Size,Morphology and Antibacterial Properties

    Institute of Scientific and Technical Information of China (English)

    R.Rajiv Gandhi; S.Gowri; J.Suresh; M.Sundrarajan

    2013-01-01

    Systematic analysis about the exploitation of imidazolium based ionic liquids (ILs),[BMIM] BF4 [IL1],[EMIM] BF4 [IL2] and [BMIM] PF6 [IL3] as the morphological template on the basic sol-gel method adopted synthesis of nanostructured zinc oxide (ZnO) is presented.X-ray diffraction (XRD),particle size analysis (PSA) and scanning electron microscopy (SEM) have been employed for the characterization of structure and morphology of the synthesized ZnO particles.Well-defined capsule like shaped morphology with lower nanosize is observed for the ZnO nanoparticles with IL1 than those with IL2 and IL3.This confirms that IL1 served as an effective templating material due to their unique properties.Especially the effective aggregation of ZnO particles with a self-organized frame of IL1 was the essential factor to produce the lower nanosized ZnO with capsule shaped structure.The synthesized ZnO samples with IL2 and IL3 fabricated the flake like shaped and rod like shaped morphologies in the range of nanoscale.The formed ZnO nanoparticles with IL2 exhibit higher nanosize than the ZnO nanoparticles produced by IL1,owing to shorter length of alkyl group in its cation which restricts steric effect and permits the nanoparticles to grow longer.Even though IL3 produced the discrete ZnO nanorods,the hydrophobic nature of IL3 created the higher nanosize than the ZnO nanoparticles formed by other two ionic liquids.Antibacterial properties of the synthesized ZnO nanostructures were investigated against Staphylococcus aureus (gram positive) and Escherichia coli (gram negative) bacteria by Agar diffusion test method.Microbial experiments indicate that the synthesized ZnO samples show a wide spectrum of antimicrobial activities and performed better against S.aureus than E.coli with the same concentration of ZnO.

  7. Binuclear ruthenium η6-arene complexes with tetradentate N,S-ligands containing the ortho-aminothiophenol motif.

    Science.gov (United States)

    Acosta-Ramirez, Alberto; Cross, Edward D; McDonald, Robert; Bierenstiel, Matthias

    2014-02-28

    A series of cationic binuclear (η(6)-cymene-Ru)2 complexes with N2S2-ligands were synthesized in 64% to 85% yield by reaction of [Ru(η(6)-cymene)Cl2]2 with bis-S,S'-(ortho-aminothiophenol)-xylenes as BF4(-) and PF6(-) salts. The compounds were studied using NMR, HRMS, UV-vis and IR spectroscopy, EA and inductively coupled plasma (ICP) MS. It was determined that the hinged binuclear Ru complexes were anti and syn diastereomers obtained in 2 : 1 ratio for ortho- and meta-xylylene bridged ligands and in a 1 : 1 ratio for the para-xylylene bridged ligand. An anion effect was found for the presence of NaBF4 with the meta-xylylene bridged system yielding the targeted binuclear Ru complex and a mononuclear Ru complex. This mononuclear S,S'-coordinated η(6)-cymene Ru chloride structure lacked amine-metal coordination and was obtained in a 1 : 3 ratio of anti : syn diastereomers which were insoluble in CH2Cl2 and soluble in DMSO and DMF. X-ray crystallographic analysis was obtained for the N2S2 ligand, 1,2-bis{(2-aminophenyl)thiomethyl}benzene, showing a CS symmetry with amine groups facing outwards with a tilt of 28.95° from the ortho-aminothiophenol pendant ring. The interatomic sulfur-sulfur distance (S-S') is 4.6405 Å within the crystal structure while accommodating a potential metal bite angle from 1.0 Å to 5.9 Å when allowing rotation of the methylene phenyl bond. PMID:24284434

  8. Electron oxidation of graphite by fluorospecies

    International Nuclear Information System (INIS)

    The fluoride-ion affinity (A/sub F-/) of phosphorus pentafluoride was determined to be 100 kcal/mole from the heats of reaction of the Lewis bases SF4 and ClO2F with PF5 near room temperature. The fluoride-ion affinity of boron trifluoride was determined to be 92 kcal/mole from the heat of reaction of ClO2F with BF3. The crystal structure of ClO2BF4 was determined and a precise lattice energy was calculated from this structure and used to determined A/sub F-/. Both PF5 and BF3 were found to react with graphite in the presence of fluorine gas to yield a variety of non-stoichiometric compounds. The fluoride-ion affinity of silicon tetrafluoride is not known, but it does not react with graphite and F2 except at high pressures. These and previous results suggested a threshold in oxidizing power of intercalating species below which the oxidative intercalation reaction would not occur. The reduction of C/sub x/PF6 by PF3 proved that the reaction is thermodynamically controlled to some extent. The displacement of PF5 in C/sub x/PF6 by BF3 (with a smaller A/sub F-/) suggested that two BF3 molecules may have a larger fluoride-ion affinity than one PF5 and that B2F7- may be a stable anion in graphite. Conductivity studies of PF/sub x/ and BF/sub y/ salts showed that a large drop in conductivity when the reaction reaches first stage is due in the most part to direct fluorination of carbon in graphite

  9. Synthesis, structure and photophysical properties of a highly luminescent terpyridine-diphenylacetylene hybrid fluorophore and its metal complexes.

    Science.gov (United States)

    Ghosh, Biswa Nath; Topić, Filip; Sahoo, Prasit Kumar; Mal, Prasenjit; Linnera, Jarno; Kalenius, Elina; Tuononen, Heikki M; Rissanen, Kari

    2015-01-01

    A new fluorescent terpyridyl-diphenylacetylene hybrid fluorophore 4'-[4-{(4-methoxyphenyl)ethynyl}phenyl]-2,2':6',2''-terpyridine, L, was synthesized via Sonogashira cross-coupling of 4'-(4-bromophenyl)-2,2':6',2''-terpyridine and 4-ethynylanisole in the presence of Pd(PPh3)4/CuI as a catalyst. The solid state structure of L shows a trans arrangement of pyridine nitrogen atoms along the interannular bond in the terpyridine domain. Five transition metal complexes of L, {[FeL2](CF3SO3)2 (1), [ZnL2](ClO4)2 (2), [CdL2](ClO4)2 (3), [RuL2](PF6)2 (4), and PtMe3IL (5)}, have also been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. The X-ray crystal structures of complexes 1-3 show a distorted octahedral MN6 arrangement with tridentate coordination of the two terpyridine ligands, whereas in complex 5 the ligand L binds in a bidentate fashion. The ligand L displays bright blue emission in the solid state and in both non-polar and polar organic media. The fluorescence quantum yield of L is exceptionally high for a monoterpyridine ligand of its kind, which can be rationalized with density functional theory calculations. The electronic structure of L shows that the fluorescence involves intramolecular charge transfer from the diphenylacetylene moiety to the terpyridine group, and it is not affected by the usual non-radiative relaxation processes such as pyridine rotation. The Fe(II), Ru(II) and Pt(IV) complexes of L were found to be non-emissive, whereas both Zn(II) and Cd(II) complexes displayed significant green emission attributed to intra-ligand charge transfer states. These results were supported by the observed red-shift of the emission maxima of complexes 2 and 3 with increasing the solvent polarity. PMID:25373423

  10. Life-Cycle Perspectives on Aquatic Ecotoxicity of Common Ionic Liquids.

    Science.gov (United States)

    Mehrkesh, Amirhossein; Karunanithi, Arunprakash T

    2016-07-01

    This study compares the aquatic ecotoxicity impacts of production- and use-phase release of five common ionic liquids (ILs). Integrating toxicity data, physical properties, and fate and transport parameters with the USEtox model, we report, for the first time, the freshwater ecotoxicity characterization factors for [Bmim](+)[Br](-), [Bmim](+)[Cl], [Bmim](+)[BF4](-), [Bmim](+)[PF6](-), and [BPy](+)[Cl](-) as 624, 748, 823, 927, and 1768 CTUe/kg, respectively. IL Production life cycle inventories were modeled and utilized to estimate their production-side ecotoxicity impacts. Literature on environmental aspects of ILs propagates either their green characteristics (no air emissions and high recyclability) or their nongreen aspects due to toxicity concerns of their release to water. This study adds a third dimension by showing that the upstream ecotoxicity impacts of producing ILs could outweigh the potential ecotoxicity impacts of direct release during use. Furthermore, for the studied ILs, an average of 83% of ecotoxicity impacts associated with their production can be linked to chemicals and materials released during the upstream synthesis steps, while only 17% of ecotoxicity impacts relate to life-cycle energy consumption. The findings underscore the need to develop sustainable synthesis routes, tight control over chemical releases during production, and careful selection of precursor materials and production processes. PMID:26599072

  11. Synthesis of gold nanoparticles by laser ablation of an Au foil inside and outside ionic liquids

    Science.gov (United States)

    Wender, Heberton; Andreazza, Marcos L.; Correia, Ricardo R. B.; Teixeira, Sérgio R.; Dupont, Jairton

    2011-03-01

    Stable gold nanoparticles (AuNPs) were prepared by simple laser ablation of an Au foil placed inside or outside four ionic liquids (ILs), without the addition of any external chemical reagent. Irregular spherical AuNPs with a diameter range of 5 to 20 nm were produced after laser ablation of an Au foil located inside or outside the ILs 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4), 1-n-butyl-3-methylimidazolium hexafluorophosphate (BMI.PF6) and 1-(3-cyanopropyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((BCN)MI.NTf2). Additionally, whereas laser ablation inside the IL 1-n-butyl-3-methylimidazolium dicyanamide BMI.N(CN)2 produced flower-like shaped nanoparticles of about 50 nm in size, ablation outside this IL presented similar results to the others ILs studied, as determined by TEM and UV-Vis. The size and shape of the prepared NPs were related to where NP nucleation and growth occurred, i.e., at the IL surface or within the IL. Indeed, the chemical composition of the IL/air interface and surface ion orientation played important roles in the stabilization of the AuNPs formed by laser ablation outside the ILs.

  12. Liquid-liquid extraction to lithium isotope separation based on room-temperature ionic liquids containing 2,2'-binaphthyldiyl-17-crown-5

    International Nuclear Information System (INIS)

    A novel liquid-liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquids (ILs = C8mim+PF6-, C8mim+BF4-, and C8mim+NTf2-) as extraction solvent and 2,2'-binaphthyldiyl-17-crown-5 (BN-17-5) as extractant. The effects of the concentration of lithium salt, counter anion of lithium salt, initial pH of aqueous phase, extraction temperature, and time on the lithium isotopes separation were discussed. Under optimized conditions, the maximum single-stage separation factor α of 6Li/7Li obtained in the present study was 1.046 ± 0.002, indicating the lighter isotope 6Li was enriched in IL phase while the heavier isotope 7Li was concentrated in the solution phase. The formation of 1:1 complex Li(BN-17-5)+ in the IL phase was determined on the basis of slope analysis method. The large value of the free energy change (-ΔG° = 92.89 J mol-1) indicated the high separation capability of the Li isotopes by BN-17-5/IL system. Lithium in Li(BN-17-5)+ complex was stripped by 1 mol L-1 HCl solution. The extraction system offers high efficiency, simplicity, and green application prospect to lithium isotope separation. (author)

  13. Sulfone-carbonate ternary electrolyte with further increased capacity retention and burn resistance for high voltage lithium ion batteries

    Science.gov (United States)

    Xue, Leigang; Lee, Seung-Yul; Zhao, Zuofeng; Angell, C. Austen

    2015-11-01

    Safety and high energy density are the two focus issues for current lithium ion batteries. For safety, it has been demonstrated that sulfone electrolytes are much less flammable than the prevailing all-carbonate type, and they are also promising for high voltage batteries due to the high oxidization resistance. However, the high melting points and viscosities greatly restricted their application. Based on our previous work on use of fluidity-enhancing cosolvents to make binary sulfone-carbonate electrolytes, we report here a three-component system that is more conductive and should be even less flammable while additionally having better low temperature stability. The conductivity-viscosity relations have been determined for this electrolyte and are comparable to those of the "standard" carbonate electrolyte. The additional component also produces much improved capacity retention for the LiNi0.5Mn1.5O4 cathode. As with carbonate electrolytes, increase of temperature to 55 °C leads to rapid capacity decrease during cycling, but the capacity loss is due to the salt, not the solvent. The high discharge capacity observed at 25 °C when LiBF4 replaces LiPF6, is fully retained at 55 °C.

  14. Interfacial structure and orientation of confined ionic liquids on charged quartz surfaces.

    Science.gov (United States)

    Wang, Yong-Lei; Laaksonen, Aatto

    2014-11-14

    Atomistic molecular dynamics simulations have been performed to study microscopic ionic structures and orientational preferences of absorbed [BMIM] cations and four paired anions ([BF4], [PF6], [TFO] and [TF2N]) on quartz surfaces. Two chemically different quartz surface models were adopted: one is saturated with silanol Si(OH)2 groups, and the other one is covered by silane SiH2 groups, respectively. Simulation results reveal that dense ionic layers, characterized by distinct mass, number, charge and electron densities, are formed in quartz interfacial region. The orientational preferences of confined ionic groups are characterized with different features depending on the size and shape of anionic groups, and the quartz surface charge. The [BMIM] cations attach exclusively onto the negatively charged Si(OH)2 surface. The imidazolium rings lie preferentially perpendicular to Si(OH)2 surface, to which the directly connected methyl and butyl chains are oriented and elongated along Si(OH)2 surface, respectively. The anions are mainly absorbed on positively charged SiH2 surface. The main axes of asymmetric [TFO] and [TF2N] anions are perpendicular and parallel to SiH2 surface, respectively. Such distinct structural and orientational preferences of confined ionic groups attribute to the strong electrostatic interactions and the formation of hydrogen bonds between confined ionic species and quartz interfacial groups. PMID:25260202

  15. Improvement of the cloud point extraction of uranyl ions by the addition of ionic liquids.

    Science.gov (United States)

    Gao, Song; Sun, Taoxiang; Chen, Qingde; Shen, Xinghai

    2013-12-15

    The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

  16. Solubility of β-cyclodextrin in different mixed solvents

    Institute of Scientific and Technical Information of China (English)

    Yu Yong; Li Jiguang; Sun Yan; Liang Qianqing; Peng Xiaoming; Liu Yansheng; Hu Yufeng

    2008-01-01

    The solubility of β-cyclodextrin(β-CD)in ionic liquid/N,N-dimethyl-acetamide(IL/DMAC)mixed solvent and in LiCl/DMAC mixed solvent was investigated at 323.15 K and 353.15 K.The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature,but decreased in LiCl/DMAC system.β-CD had the highest solubility in IL/DMAC system with[Cl]- or[Br]- anions.The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or[Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions(e.g[BF4]- or[PF6]-).The effects of substituent groups(benzyl and butyl)of cation and the structure of cations on β-cyclodextrin solubility were also investigated.

  17. Microwave-assisted ionic liquid homogeneous liquid-liquid microextraction coupled with high performance liquid chromatography for the determination of anthraquinones in Rheum palmatum L.

    Science.gov (United States)

    Wang, Zhibing; Hu, Jianxue; Du, Hongxia; He, Shuang; Li, Qing; Zhang, Hanqi

    2016-06-01

    The microwave-assisted ionic liquid homogeneous liquid-liquid microextraction (MA-IL-HLLME) coupled with high performance liquid chromatography with diode array detection (HPLC-DAD) was developed for the determination of anthraquinones, including aloe-emodin, emodin, chrysophanol and physcion in root of Rheum palmatum L. Several experimental parameters influencing the extraction efficiency, including amount of sample, type and volume of ionic liquid, volume and pH value of extraction medium, microwave power and extraction time, concentration of NH4PF6 as well as centrifugal condition were optimized. When 140μL of ionic liquid ([C8MIM][BF4]) was used as an extraction solvent, target analytes can be extracted from sample matrix in one minute with the help of microwave irradiation. The MA-IL-HLLME is simple and quick. The calibration curves exhibited good linear relationship (r>0.9984). The limits of detection and quantification were in the range of 0.015-0.026 and 0.051-0.088μgmL(-1), respectively. The spiked recovery for each analyte was in the range of 81.13-93.07% with relative standard deviations lower than 6.89%. The present method is free of volatile organic solvents, and represents lower expenditures of sample, extraction time and solvent, compared with ultrasonic and heat reflux extraction. The results indicated that the present method can be successfully applied to the determination of anthraquinones in medicinal plant.

  18. The Anion Effect on Li(+) Ion Coordination Structure in Ethylene Carbonate Solutions.

    Science.gov (United States)

    Jiang, Bo; Ponnuchamy, Veerapandian; Shen, Yuneng; Yang, Xueming; Yuan, Kaijun; Vetere, Valentina; Mossa, Stefano; Skarmoutsos, Ioannis; Zhang, Yufan; Zheng, Junrong

    2016-09-15

    Rechargeable lithium ion batteries are an attractive alternative power source for a wide variety of applications. To optimize their performances, a complete description of the solvation properties of the ion in the electrolyte is crucial. A comprehensive understanding at the nanoscale of the solvation structure of lithium ions in nonaqueous carbonate electrolytes is, however, still unclear. We have measured by femtosecond vibrational spectroscopy the orientational correlation time of the CO stretching mode of Li(+)-bound and Li(+)-unbound ethylene carbonate molecules, in LiBF4, LiPF6, and LiClO4 ethylene carbonate solutions with different concentrations. Surprisingly, we have found that the coordination number of ethylene carbonate in the first solvation shell of Li(+) is only two, in all solutions with concentrations higher than 0.5 M. Density functional theory calculations indicate that the presence of anions in the first coordination shell modifies the generally accepted tetrahedral structure of the complex, allowing only two EC molecules to coordinate to Li(+) directly. Our results demonstrate for the first time, to the best of our knowledge, the anion influence on the overall structure of the first solvation shell of the Li(+) ion. The formation of such a cation/solvent/anion complex provides a rational explanation for the ionic conductivity drop of lithium/carbonate electrolyte solutions at high concentrations.

  19. Screening of lignan patterns in Schisandra species using ultrasonic assisted temperature switch ionic liquid microextraction followed by UPLC-MS/MS analysis.

    Science.gov (United States)

    Dong, Wei; Yu, Shuijing; Deng, Yangwu; Pan, Tao

    2016-01-01

    The ultrasonic assisted temperature-switch ionic liquid microextraction (UATS-ILME) has been successfully applied in extracting of seven lignans from Schisandra. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) aqueous solution was selected for extracting the target analytes in raw material at 80°C. The lignans were deposited into a single drop by in situ forming 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) by cooling down to 0°C and centrifuging for 10min. The extracts were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in a robust multiple-reaction monitoring (MRM) mode in five minutes. Meanwhile, the proposed method was validated and successfully applied to the determination of seven lignans in twelve Schisandra species. The results indicated that UATS-ILME combined with UPLC-MS/MS is a powerful and practical tool, which has great potential for comprehensive quality control of herbal medicines.

  20. Electrochemical behavior of sebaconitrile as a cosolvent in the formulation of electrolytes at high potentials for lithium-ion batteries

    International Nuclear Information System (INIS)

    The electrochemical behavior of new high potential electrolyte containing sebaconitrile in LiPF6/EC:DMC or LiBF4 was studied on glassy carbon and LiCoO2, LiCoPO4 as positive electrode materials. The increase of sebaconitrile concentration in EC:DMC electrolyte provides better electrolyte stability at higher potentials on glassy carbon as observed by cyclic voltammetry. Promising electrochemical results showing good reversibility and insertion/deinsertion efficiency have been also obtained on LiCoPO4 electrode cycled up to 5.3 V vs Li+/Li as upper potential limit. However, the cycling of LiCoPO4 at higher potential (6 V vs Li+/Li) shows lower reversibility and efficiency of insertion/deinsertion process due to the oxidative decomposition of the electrolyte at high potentials. The surface analysis performed by X-ray photoelectron spectroscopy confirms the formation of a surface layer induced by electrolyte degradation on both types of positive electrodes, which hinder the Li diffusion. The layer composition and morphology vary as a function of electrolyte composition and type of electrode

  1. Effect of the Structure of Cations and Anions of Ionic Liquids on Separation of Aromatics from Hydrocarbon Mixtures

    Institute of Scientific and Technical Information of China (English)

    Liu Yansheng; Zhang Zhongxin; Zhang Guofu; Liu Zhichang; Hu Yufeng; Shi Quan; Ji Dejun

    2006-01-01

    The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The results showed that the corresponding separation factors were considerably larger than those of the traditional solvents (Benzene+Hexane+sulfolane), and that the ionic liquids could be used as novel solvents for the separation of aromatics from hydrocarbon mixtures. The key parameters governing the ability of ionic liquids for separating aromatics from hydrocarbon sources were investigated. It was found that the effectiveness of the ionic liquids, based on the same anion, changed in the cation order of [BIqu]+< [BPy]+< [BMIM]+. The selectivity of the ionic liquid toward aromatics decreased apparently with the increasing length of the substituted alkyl chain of its cationic head ring. The separation factors, based on the same cation, changed in the anion order of [Tf2N]-<[PF6]-<[BF4]-<[C2H5SO4]-. The solubilities of the aromatics were greater in the ionic liquids based on the former three anions than that in the ionic liquids involving [C2H5SO4]-.

  2. Probing the effects of the ester functional group, alkyl side chain length and anions on the bulk nanostructure of ionic liquids: a computational study.

    Science.gov (United States)

    Fakhraee, Mostafa; Gholami, Mohammad Reza

    2016-04-14

    The effects of ester addition on nanostructural properties of biodegradable ILs composed of 1-alkoxycarbonyl-3-alkyl-imidazolium cations ([C1COOCnC1im](+), n = 1, 2, 4) combined with [Br](-), [NO3](-), [BF4](-), [PF6](-), [TfO](-), and [Tf2N](-) were explored by using the molecular dynamics (MD) simulations and quantum theory of atoms in molecules (QTAIM) analysis at 400 K. Various thermodynamic properties of these ILs were extensively computed in our earlier work (Ind. Eng. Chem. Res., 2015, 54, 11678-11700). Nano-scale segregation analysis demonstrates the formation of a small spherical island-like hydrocarbon within the continuous ionic domain for ILs with short alkyl side chain ([C1COOC1C1im]), and a sponge-like nanostructure for the compound with long alkyl side chain ([C1COOC4C1im]). Ester-functionalized ILs with ethyl side chain ([C1COOC2C1im]) are the turning point between two different morphologies. Non-polar channels were observed for [C1COOC4C1im] ILs composed of smaller anions such as [Br] and [NO3], whereas clustering organization was found for the other anions. Formation of the spherical micelle-like nanostructure was seen for lengthened cations. Finally, the incorporation of an ester group into the alkyl side chain of the cation leads to stronger segregation between charged and uncharged networks, which consequently increased the possibility of self-assembly and micelle formation. PMID:27001746

  3. Anion effect on radiochemical stability of room-temperature ionic liquids under gamma irradiation

    International Nuclear Information System (INIS)

    Radiochemical stability of imidazolium-based ionic liquids constituted of the BuMeIm+ cation and associated with four commonly used anions (X-: Tf2N-, TfO-, PF6- and BF4-) has been investigated under gamma irradiation for high irradiation doses (up to 2.0 MGy). The anion effect has been examined by quantifying the radiolytic yields of disappearance for cation and anions and by identifying corresponding radiolysis products with several analytical techniques. On the one hand, a large number of radiolysis products are formed throughout the irradiation in ionic liquid solutions, resulting from reactions of primary generated species of cation and anion by indirect radiolysis. Primary generated species can react together throughout the irradiation by indirect radiolysis to form numerous radiolysis products in small quantities, indicating that several complex degradation pathways are involved for these radiation doses. This degradation pattern has been confirmed by identification of numerous gaseous radiolytic products. On the other hand, quantitative studies show that radiochemical stabilities of ionic liquids are in the same range of values as systems envisioned in nuclear fuel reprocessing with relatively low hydrogen yields. Indeed, this present work emphasizes the suitability of ionic liquids for applications in the nuclear fuel cycle. (authors)

  4. Aqueous Solutions of Ionic Liquids: Microscopic Assembly.

    Science.gov (United States)

    Vicent-Luna, Jose Manuel; Dubbeldam, David; Gómez-Álvarez, Paula; Calero, Sofia

    2016-02-01

    Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure-property relationships of such systems is hence desirable. One of the crucial molecular-level interactions that influences the macroscopic behavior is hydrogen bonding. In this work, we conduct molecular dynamics simulations to investigate the effects of ionic liquids on the hydrogen-bond network of water in dilute aqueous solutions of ionic liquids with various combinations of cations and anions. Calculations are performed for imidazolium-based cations with alkyl chains of different lengths and for a variety of anions, namely, [Br](-), [NO3](-), [SCN](-) [BF4](-), [PF6](-), and [Tf2N](-). The structure of water and the water-ionic liquid interactions involved in the formation of a heterogeneous network are analyzed by using radial distribution functions and hydrogen-bond statistics. To this end, we employ the geometric criterion of the hydrogen-bond definition and it is shown that the structure of water is sensitive to the amount of ionic liquid and to the anion type. In particular, [SCN](-) and [Tf2N](-) were found to be the most hydrophilic and hydrophobic anions, respectively. Conversely, the cation chain length did not influence the results.

  5. The Geometry and Structural Properties of the 4,8,12-Trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrene System in the Cationic State. Structures of a Planar Organic Cation with Various Monovalent- and Divalent Anions

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Laursen, Bo W.; Johannsen, Ib;

    1999-01-01

    The geometry of the 4,8,12-trioxa-4,8,12,12c- tetrahydrodibenzo[cd,mn]pyrene system in the cationic state was established by X-ray structural resolution of the salts formed between the cationand various anions. The geometry was found to be planar for the 4,8,12-trioxa-4,8,12,12c- tetrahydrodibenzo...... [cd,mn]pyrenylium and 2,6,10-tri (tert-butyl)-4,8,12-trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyre nylium cations with the monovalentanions I-, BF4-, PF6- AsF6-, HNO3. NO3- and CF3SO3-, and the divalent anions S2O62- and Mo6Cl142-. The salts were found to crystallize in distinct space groups...... following a characteristic pattern. Mixed cation-anion stacking resulted in space groups with high symmetry: Pbca in three cases and R (3) over bar c in one; a temperature study of the latter was made at ten different temperatures. The formation of dimers of anions and cations resulted in lower...

  6. Spin-crossover studies on a series of 1-D chain and dinuclear iron(II) triazine-dipyridylamine compounds

    International Nuclear Information System (INIS)

    Four isostructural one-dimensional polymeric iron(II) spin crossover materials containing the ligand 2-chloro-4,6-bis(dipyrid-2-ylamino)-1,3,5-triazine (cddt) have been synthesized and magnetically and structurally characterized. The polymeric material Fe(NCS)2(cddt)·n(guest) (1), self assembles into three crystallographically distinct phases; the compounds 1b and 1c, [Fe(NCS)2(cddt)]·2(CH3OH), are polymorphs, however, 1a, [Fe(NCS)2(cddt)]·1/2(CHCl3)·(H2O) contains a different solvent system. Each phase shows very different magnetic behavior; phases 1a and 1b remain high spin over all temperatures, whilst phase 1c undergoes a half spin crossover between 225 and 125 K. The structural consequences of the spin transition in 1c have been followed using variable temperature synchrotron powder X-ray diffraction techniques. Variation of the chalcogenide ligand in the complex [Fe(NCSe)2(cddt)]·2(CH3OH), 2, leads to a full one-step spin crossover with a T1/2 of 200 K. Structural analysis of 1c below the transition temperature reveals alternating, crystallographically distinct, HS and LS iron(II) centers (HS: high spin, LS: low spin) along the chain, and structural analysis of 2 below the transition temperature reveals all LS iron(II) centers. Also reported are the structural characterizations of two dinuclear materials, containing the ligand 2,4,6-tris(dipyridin-2-ylamino)-1,3,5-triazine (tdt), of the formula [Fe(tdt)(X)2]2·(ClO4)·(solvent) (X = H2O, Cl- for 3a, 3b) which are analogous to those recently reported by Gamez et al. In addition, the structural characterizations are described for dinuclear materials, containing the ligand cddt, of the formula [Fe(cddt)(Cl)(X)]2·(Y)2·n(solvent) (X: H2O or NCCH3, Y: ClO4-, BF4- 4a, 4b and 4d) and for a cobalt(II) analogue, [Co(cddt)(Cl)(H2O)]2·(BF4)2·n(solvent) (4c)

  7. Fe(II) Spin Transition Materials Including an Amino-Ester 1,2,4-Triazole Derivative, Operating at, below, and above Room Temperature.

    Science.gov (United States)

    Dîrtu, Marinela M; Naik, Anil D; Rotaru, Aurelian; Spinu, Leonard; Poelman, Dirk; Garcia, Yann

    2016-05-01

    A new family of one-dimensional Fe(II) 1,2,4-triazole spin transition coordination polymers for which a modification of anion and crystallization solvent can tune the switching temperature over a wide range, including the room temperature region, is reported. This series of materials was prepared as powders after reaction of ethyl-4H-1,2,4-triazol-4-yl-acetate (αEtGlytrz) with an iron salt from a MeOH/H2O medium affording: [Fe(αEtGlytrz)3](ClO4)2 (1); [Fe(αEtGlytrz)3](ClO4)2·CH3OH (2); [Fe(αEtGlytrz)3](NO3)2·H2O (3); [Fe(αEtGlytrz)3](NO3)2 (4); [Fe(αEtGlytrz)3](BF4)2·0.5H2O (5); [Fe(αEtGlytrz)3](BF4)2 (6); and [Fe(αEtGlytrz)3](CF3SO3)2·2H2O (7). Their spin transition properties were investigated by (57)Fe Mossbauer spectroscopy, superconducting quantum interference device (SQUID) magnetometry, and differential scanning calorimetry (DSC). The temperature dependence of the high-spin molar fraction derived from (57)Fe Mössbauer spectroscopy in 1 reveals an abrupt single step transition between low-spin and high-spin states with a hysteresis loop of width 5 K (Tc(↑) = 296 K and Tc(↓) = 291 K). The properties drastically change with modification of anion and/or lattice solvent. The transition temperatures, deduced by SQUID magnetometry, shift to Tc(↑) = 273 K and Tc(↓) = 263 K for (2), Tc(↑) = 353 K and Tc(↓) = 333 K for (3), Tc(↑) = 338 K and Tc(↓) = 278 K for (4), T(↑) = 320 K and T(↓) = 305 K for (5), Tc(↑) = 106 K and Tc(↓) = 92 K for (6), and T(↑) = 325 K and T(↓) = 322 K for (7). Annealing experiments of 3 lead to a change of the morphology, texture, and magnetic properties of the sample. A dehydration/rehydration process associated with a spin state change was analyzed by a mean-field macroscopic master equation using a two-level Hamiltonian Ising-like model for 3. A new structural-property relationship was also identified for this series of materials [Fe(αEtGlytrz)3](anion)2·nSolvent based on Mössbauer and DSC

  8. 配位聚合物[Mn(4,4'-bpy)1.5(H2O)3](CIO4)·(4,4'-bpy)(L)·H2O的水热合成和晶体结构%Hydrothermal Synthesis and Crystal Structure of Coordination Polymer [Mn(4,4'-bpy)1.5(H2O)3] (ClO4)· (4,4'-bpy)(L)· H2O

    Institute of Scientific and Technical Information of China (English)

    黄妙龄

    2007-01-01

    The title compound, [Mn(4,4'-bpy)1.5(H2O)3](C1O4)·(4,4'-bpy)(L)· H2O(1), where L=2,4,6-trimethylbenzoic acid, was synthesized and its crystal structure was determined by X-ray diffraction analysis. The crystal is of triclinic, space group P(-1) with a=2.929 9(6) nm, b=1.0364(2) nm, c=8.222 0(1) nm, α=105.300(2)°, β=97.495(2)°,0.135 2. The Mn atoms are octahedrally coordinated by three N atoms of three 4,4'-bipyridine ligands and three O atoms of water. The complex shows a one-dimensional chain structure bridged by water and 4,4'-bipyridine molecules. CCDC: 615707.

  9. Synthesis and Crystal Structure of a Novel Tetranuclear Yttrium Complex With Proline Ligands at High pH Value%高pH下钇-L-脯氨酸四核配合物[Y4(HPrO)4(PRO)2 (μ3-OH)4 (H2O)7] (ClO4)6@6H2O的合成与晶体结构*

    Institute of Scientific and Technical Information of China (English)

    陈德; 张大顺; 李琳; 马宝清; 金天柱

    2000-01-01

    在水溶液中,调节pH至6.3,合成了高氯酸钇与L-脯氨酸的配合物[Y4(HPrO)4(PrO)2(μ3-OH)4(H2O)7](CIO4)6@6H2O单晶,并测定了其晶体结构.该晶体属菱形晶系,R3空间群,晶胞参数:a=b=c=12.786 3(15)A,α=β=γ=100.217(17)0,V=1977.0(4)A3,Z=1,最终偏差因子R1=0.086 9,wR2=0.220 3.每个晶胞以四个Y3+通过四个μ3-OH-离子、六个脯氨酸羧基桥联成四核簇状结构.其中三个Y3+每个均与三个μ3-OH、三个羧基氧原子、两个水分子配位,其配位数为8;另一个Y3+与三个μ3-OH、三个羧基氧原子、一个水分子配位,其配位数为7.

  10. Macrocyclic nickel(II) complexes: Synthesis, characterization, superoxide scavenging activity and DNA-binding

    Science.gov (United States)

    Ramadan, Abd El-Motaleb M.

    2012-05-01

    A new series of nickel(II) complexes with the tetraaza macrocyclic ligand have been synthesized as possible functional models for nickel-superoxide dismutase enzyme. The reaction of 5-amino-3-methyl-1-phenylpyrazole-4-carbaldehyde (AMPC) with itself in the presence of nickel(II) ion yields, the new macrocyclic cationic complex, [NiL(NO3)2], containing a ligand composed of the self-condensed AMPC (4 mol) bound to a single nickel(II) ion. A series of metathetical reactions have led to the isolation of a number of newly complexes of the types [NiL]X2; X = ClO4 and BF4, [NiLX2], X = Cl and Br (Scheme 1). Structures and characterizations of these complexes were achieved by several physicochemical methods namely, elemental analysis, magnetic moment, conductivity, and spectral (IR and UV-Vis) measurements. The electrochemical properties and thermal behaviors of these chelates were investigated by using cyclic voltammetry and thermogravimetric analysis (TGA and DTG) techniques. A distorted octahedral stereochemistry has been proposed for the six-coordinate nitrato, and halogeno complexes. For the four-coordinate, perchlorate and fluoroborate, complex species a square-planar geometry is proposed. The measured superoxide dismutase mimetic activities of the complexes indicated that they are potent NiSOD mimics and their activities are compared with those obtained previously for nickel(II) complexes. The probable mechanistic implications of the catalytic dismutation of O2rad - by the synthesized nickel(II) complexes are discussed. The DNA-binding properties of representative complexes [NiLCl2] and [NiL](PF4)2 have been investigated by the electronic absorption and fluorescence measurements. The results obtained suggest that these complexes bind to DNA via an intercalation binding mode and the binding affinity for DNA follows the order: [NiLCl2] □ [NiL](PF4)2.

  11. Structural diversity in iron(II) complexes of 2,6-di(pyrazol-1-yl)pyridine and 2,6-di(3-methylpyrazol-1-yl)pyridine.

    Science.gov (United States)

    Elhaïk, Jérôme; Kilner, Colin A; Halcrow, Malcolm A

    2006-02-14

    The syntheses, magnetochemistry and crystallography of [Fe(L1)2]I0.5[I3]1.5 (1), [Fe(L1)2][Co(C2B9H11)2]2 (2) and [Fe(L2)2][SbF6]2 (3) (L1 = 2,6-di(pyrazol-1-yl)pyridine; L2 = 2,6-di(3-methylpyrazol-1-yl)pyridine) are described. Compounds 1 and 3 are high-spin between 5-300 K. For 1, this reflects a novel variation of an angular Jahn-Teller distortion at the iron centre, which traps the molecule in its high-spin state. No such distortion is present in 3; rather, the high-spin nature of this compound may reflect ligand conformational strain caused by an intermolecular steric contact in the crystal lattice. Compound 2 exhibits a gradual high --> low spin transition upon cooling with T(1/2) = 318 +/- 3 K, that is only 50% complete. This reflects the presence of two distinct, equally populated iron environments in the solid. One of these unique iron centres adopts the same angular structural distortion shown by 1 and so is trapped in its high-spin state, while the other, which undergoes the spin-crossover, has a more regular coordination geometry. In contrast with 3, the solvated salts [Fe(L2)2][BF4]2 x 4 CH3CN and [Fe(L2)2][ClO4]2 x (CH3)2CO both undergo gradual thermal spin-transitions centred at 175 +/- 3 K. PMID:16437177

  12. Encapsulated discrete octameric water cluster, 1D water tape, and 3D water aggregate network in diverse MOFs based on bisimidazolium ligands

    Science.gov (United States)

    Shi, Ruo-Bing; Pi, Min; Jiang, Shuang-Shuang; Wang, Yuan-Yuan; Jin, Chuan-Ming

    2014-08-01

    Four new metal-organic frameworks, [Zn(2-mBIM)2(SO3CF3)2·(H2O)4] (1), [Zn(BMIE)(1,4-BDC)]·(H2O)3 (2), [Cd(BIM)2(OH)(H2O)2(PF6)]·(H2O)4 (3), and [Cd(PA-BIM)2 (ClO4)2]·11.33H2O (4) (2-mBIM = bis(2-methylimidazol-1-yl)methane, BMIE = 1,2-bis[1-(2-methylimidazole)-diethoxy]ethane, BIM = bis(imidazol-1-yl)methane, and PA-BIM = 1,1-bis [(2-phenylazo)imidazol-1-yl]methane) have been prepared and structurally characterized. Complex 1 exhibits an infinite 1D cationic beaded-chain structure, which encapsulated discrete octameric water clusters that are comprised of a chair-like hexameric water cluster with two extra water molecules dangling on two diagonal vertices of the chair. Complex 2 forms a 1D infinite zigzag metal-organic chain structure with a 1D T4(0)A(4) water tape. Complexes 3 show a 2D grid-like sheet structure with the 1D water tape T4(0)A(0)2(0) motif. Complex 4 is a porous 3D MOF with tetrahedron-coordinated Cd(II) centers and trans-conformation PA-BIM ligands. These holes are occupied by a fascinating three-dimensional water clathrate network, which consists of cage-shaped structural tetradecameric water cluster (H2O)14 units and six independent bridged water molecules. The results suggest that the bisimidazolium ligands and anions play crucial roles in the formation of the different host structures and different guest water aggregations. Additionally, the thermal stabilities and photoluminescence spectra of the complexes have been discussed.

  13. Measurement of lithium ion transference numbers of electrolytes for lithium-ion batteries. A comparative study with five various methods.; Messung von Lithium-Ionen Ueberfuehrungszahlen an Elektrolyten fuer Lithium-Ionen Batterien. Eine vergleichende Studie mit fuenf verschiedenen Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Zugmann, Sandra

    2011-03-30

    number and ideally activity coefficients. The new electrolyte lithium difluoromono(oxalato)borate LiDFOB in EC/DEC (3/7) was for example fully determined at 25 C in this work. In comparison with other salts (LiPF6 und LiBF4) it proves to be an appropriate electrolyte for lithium-ion batteries. It generates no HF by hydrolysis that avoids the use of environment friendly and cost-effective manganese spinels, and it much better soluble as lithium bis(oxalato)borate LiBOB. In addition LiDFOB protects aluminum from corrosion and is more thermal stable as the standard salt LiPF6.

  14. 锂盐型电力复合脂的导电性和摩擦学性能%Electrical Conductivities and Tribological Properties of Lithium Salts Conductive Grease

    Institute of Scientific and Technical Information of China (English)

    葛翔宇; 夏延秋; 冯欣; 宋玉旺; 樊小强

    2015-01-01

    以三种锂盐:四氟硼酸锂(LiBF4)、六氟磷酸锂(LiPF6)和双三氟甲烷磺酰亚胺锂(LiNTf2)作为锂基润滑脂导电剂制得了三种电力复合脂。分别采用 DDSJ-308A型电导率仪,GEST-121型体积表面电阻率测试仪和HLY-200A型回路电阻测试仪对电力复合脂的导电性进行了测试。并采用Optimol SRV-I型振荡往复摩擦磨损试验机对电力复合脂在室温下的摩擦学性能进行了测试。结果表明,三种锂盐可以提高润滑脂的导电性,还可以改善润滑脂的摩擦学性能。利用Micro-XAM3D 轮廓扫描仪测量了磨痕体积,采用扫描电子显微镜和PHI-5702型多功能X射线光电子能谱仪对磨损表面进行了表征和分析。分析结果表明,在摩擦过程中形成了包含吸附膜和化学反应膜的边界膜,使得减摩抗磨性能得到了改善。%Three kinds of conductive grease are prepared by adding three lithium salts, including lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6) and lithium bis (trifluoromethane sulfonamide) (LiNTf2) in lithium grease. The electrical conductive properties of the prepared conductive greases are evaluated by using a DDSJ-308A conductivity meter, a GEST-121 volume surface resistance tester and a HLY-200A circuit resistance tester, respectively. And the tribological behaviors of three kinds of lithium salts are investigated by an Optimol SRV-I oscillating reciprocating friction and wear tester at room temperature (RT). The results demonstrate that the addition of lithium salts can enhance the lithium grease conductivity and also dramatically improve the tribological properties of lithium grease, the wear volumes are valued by Micro-XAM3D noncontact surface mapping profiler, wear surface are characterized and analyzed based on scanning electron microscope (SEM) and PHI-5702 multifunctional X-ray photoelectron spectrometer (XPS). The results indicate the improvement of tribological properties

  15. High flash point electrolyte for use in lithium-ion batteries

    International Nuclear Information System (INIS)

    Highlights: → Substitution of linear carbonates in conventional electrolytes with adiponitrile allows the realization of high flash point electrolytes. → EC:ADN based electrolytes display a higher anodic stability than a conventional electrolyte based on EC:DEC. → Graphite and NCM electrodes used in combination with the EC:ADN based electrolyte display a performance comparable with that of conventional electrolytes. - Abstract: The high flash point solvent adiponitrile (ADN) was investigated as co-solvent with ethylene carbonate (EC) for use as lithium-ion battery electrolyte. The flash point of this solvent mixture was more than 110 deg. C higher than that of conventional electrolyte solutions involving volatile linear carbonate components, such as diethyl carbonate (DEC) or dimethyl carbonate (DMC). The electrolyte based on EC:ADN (1:1 wt) with lithium tetrafluoroborate (LiBF4) displayed a conductivity of 2.6 mS cm-1 and no aluminum corrosion. In addition, it showed higher anodic stability on a Pt electrode than the standard electrolyte 1 M lithium hexafluorophosphate (LiPF6) in EC:DEC (3:7 wt). Graphite/Li half cells using this electrolyte showed excellent rate capability up to 5C and good cycling stability (more than 98% capacity retention after 50 cycles at 1C). Additionally, the electrolyte was investigated in NCM/Li half cells. The cells were able to reach a capacity of 104 mAh g-1 at 5C and capacity retention of more than 97% after 50 cycles. These results show that an electrolyte with a considerably increased flash point with respect to common electrolyte systems comprising linear carbonates, could be realized without any negative effects on the electrochemical performance in Li-half cells.

  16. Saturation properties of 1-alkyl-3-methylimidazolium based ionic liquids.

    Science.gov (United States)

    Rane, Kaustubh S; Errington, Jeffrey R

    2014-07-24

    We study the liquid-vapor saturation properties of room temperature ionic liquids (RTILs) belonging to the homologous series 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][NTf2]) using Monte Carlo simulation. We examine the effect of temperature and cation alkyl chain length n on the saturated densities, vapor pressures, and enthalpies of vaporization. These properties are explicitly calculated for temperatures spanning from 280 to 1000 K for RTILs with n = 2, 4, 6, 8, 10, and 12. We also explore how the identity of the anion influences saturation properties. Specifically, we compare results for [C(4)mim][NTf2] with those for 1-butyl-3-methylimidazolium tetrafluoroborate ([C(4)mim][BF4]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF6]). Simulations are completed with a recently developed realistic united-atom force field. A combination of direct grand canonical and isothermal-isobaric temperature expanded ensemble simulations are used to construct phase diagrams. Our results are compared with experimental data and Gibbs ensemble simulation data. Overall, we find good agreement between our results and those measured experimentally. We find that the vapor pressures and enthalpies of vaporization show a strong dependence on the size of the alkyl chain at low temperatures, whereas no particular trend is observed at high temperatures. Finally, we also discuss the effect of temperature on liquid phase nanodomains observed in RTILs with large hydrophobic groups. We do not observe a drastic change in liquid phase structure upon variation of the temperature, which suggests there is not a sharp phase transition between a nanostructured and homogeneous liquid, as has been suggested in earlier studies. PMID:24986360

  17. Hydroxyl-functionalized 1-(2-hydroxyethyl)-3-methyl imidazolium ionic liquids: thermodynamic and structural properties using molecular dynamics simulations and ab initio calculations.

    Science.gov (United States)

    Fakhraee, Mostafa; Zandkarimi, Borna; Salari, Hadi; Gholami, Mohammad Reza

    2014-12-11

    The influences of hydroxyl functional group (-OH) on the thermodynamic and structural properties of ionic liquids (ILs) composed of 1-(2-Hydroxyethyl)-3-methyl imidazolium ([C2OHmim](+)) cation and the six different conventional anions, including [Cl](-), [NO3](-), [BF4](-), [PF6](-), [TfO](-), and [Tf2N](-) have been extensively investigated using classical molecular dynamics (MD) simulations combined with ab initio calculations over a wide range of temperature (298-550 K). The volumetric thermodynamic properties, enthalpy of vaporization, cohesive energy density, Hildebrand solubility parameter, and heat capacity at constant pressure were estimated at desired temperature. The simulated densities were in good agreement with the experimental data with a slight overestimation. The interionic interaction of selected ILs was also computed using both the MD simulations and ab initio calculations. It was found that the highest association of cation and anion is attributed to [C2OHmim][Cl] followed by [C2OHmim][NO3], and [C2OHmim][Tf2N] with the bulkiest anion has the weakest interionic interaction among chosen ILs. The similar trend of interactions energies was nearly observed from cohesive energy density results. Additional structural details were comprehensively yielded by calculating radial distribution functions (RDFs) and spatial distribution function (SDFs) at 358 K. The most stable configurations of isolated and dimer ion pairs of these ILs were in excellent consistency with RDFs and SDFs results. Significant changes in arrangement of anions around the [C2OHmim](+) cation in comparison with conventional imidazolium-based ILs can be inferred from the MD simulations and ab initio results. Also, microscopic structural properties disclosed that the most strong cation-cation interaction is ascribed to the hydroxyl-functionalized ILs composed of bulkier anions, whereas ILs incorporating [Cl](-) and [NO3](-) anions are mainly involved in cation-anion interactions. The

  18. Ionic liquids as an electrolyte for the electro synthesis of organic compounds.

    Science.gov (United States)

    Kathiresan, Murugavel; Velayutham, David

    2015-12-25

    The use of ionic liquids (ILs) as a solvent and an electrolyte for electro organic synthesis has been reviewed. To date several ILs exist, however the ILs based on tetraalkylammonium, pyrrolidinium, piperidinium and imidazolium cations with BF4(-), PF6(-), and TFSI anions have been widely used and explored the most. Electro organic synthesis in ionic liquid media leading to the synthesis of a wide range of organic compounds has been discussed. Anodic oxidation or cathodic reduction will generate radical cation or anion intermediates, respectively. These radicals can undergo self coupling or coupling with other molecules yielding organic compounds of interest. The cation of the IL is known to stabilize the radical anion extensively. This stabilization effect has a specific impact on the electrochemical CO2 reduction and coupling to various organics. The relative stability of the intermediates in IL leads to the formation of specific products in higher yields. Electrochemical reduction of imidazolium or thiazolium based ILs generates N-heterocyclic carbenes that have been shown to catalyze a wide range of base or nucleophile catalyzed organic reactions in IL media, an aspect that falls into the category of organocatalysis. Electrochemical fluorination or selective electrochemical fluorination is another fascinating area that delivers selectively fluorinated organic products in Et3N·nHF or Et4NF·nHF adducts (IL) via anodic oxidation. Oxidative polymerization in ILs has been explored the most; although morphological changes were observed compared to the conventional methods, polymers were obtained in good yields and in some cases ILs were used as dopants to improve the desired properties.

  19. Free volume in ionic liquids: a connection of experimentally accessible observables from PALS and PVT experiments with the molecular structure from XRD data.

    Science.gov (United States)

    Beichel, Witali; Yu, Yang; Dlubek, Günter; Krause-Rehberg, Reinhard; Pionteck, Jürgen; Pfefferkorn, Dirk; Bulut, Safak; Bejan, Dana; Friedrich, Christian; Krossing, Ingo

    2013-06-14

    In the current work, free volume concepts, primarily applied to glass formers in the literature, were transferred to ionic liquids (ILs). A series of 1-butyl-3-methylimidazolium ([C4MIM](+)) based ILs was investigated by Positron Annihilation Lifetime Spectroscopy (PALS). The phase transition and dynamic properties of the ILs [C4MIM][X] with [X](-) = [Cl](-), [BF4](-), [PF6](-), [OTf](-), [NTf2](-) and [B(hfip)4](-) were reported recently (Yu et al., Phys. Chem. Chem. Phys., 2012, 14, 6856-6868). In this subsequent work, attention was paid to the connection of the free volume from PALS (here the mean hole volume, ) with the molecular structure, represented by volumes derived from X-ray diffraction (XRD) data. These were the scaled molecular volume Vm,scaled and the van der Waals volume V(vdw). Linear correlations of at the "knee" temperature ((T(k))) with V(m,scaled) and V(vdw) gave good results for the [C4MIM](+) series. Further relationships between volumes from XRD data with the occupied volume Vocc determined from PALS/PVT (Pressure Volume Temperature) measurements and from Sanchez-Lacombe Equation of State (SL-EOS) fits were elaborated (V(occ)(SL-EOS) ≈ 1.63 V(vdw), R(2) = 0.981 and V(occ)(SL-EOS) ≈ 1.12 V(m,scaled), R(2) = 0.980). Finally, the usability of V(m,scaled) was justified in terms of the Cohen-Turnbull (CT) free volume theory. Empirical CT type plots of viscosity and electrical conductivity showed a systematic increase in the critical free volume with molecular size. Such correlations allow descriptions of IL properties with the easily accessible quantity V(m,scaled) within the context of the free volume.

  20. Modeling stability and flexibility of α-Chymotrypsin in room temperature ionic liquids.

    Science.gov (United States)

    Latif, Muhammad A M; Tejo, Bimo A; Abedikargiban, Roghayeh; Abdul Rahman, Mohd B; Micaêlo, Nuno M

    2014-01-01

    We investigate the structure and dynamics of α-Chymotrypsin in five room temperature ionic liquids (RTILs) sharing a common cation, hydrated with different water percentages (w/w) (weight of water over protein). Results from molecular dynamics simulations are correlated with experimental evidences from studies on the activity of enzymes in RTILs. α-Chymotrypsin protein structure is closer to its native crystallographic structure in RTILs than in aqueous environment. We show that the structural properties of α-Chymotrypsin were affected by the water concentration assayed in a typical bell-shaped profile, which is also frequently reported for organic solvents. The protein structure was more native like at 10-20% of water (w/w) for all RTILs except for [BMIM][Cl]. We found that the fluctuations of the main chain in [BMIM][BF4] and [BMIM][TfO] were not significantly affected by the increasing amount of water. However, we were able to show that the flexible regions were the ones more hydrated, indicating that water is responsible for the flexibility of the protein. The solvation of the enzyme in water-immiscible RTILs, such as [BMIM][PF6] and [BMIM][Tf2N] lead to higher enzyme flexibility at increased water content. Enzyme solvation by [BMIM][Cl] resulted in ion penetration in the core enzyme structure, causing incremented flexibility and destabilization at low water percentages. All RTILs stripped water molecules from the protein surface, following a similar behavior also found in organic solvents. Anions formed structured arrangements around the protein, which allowed non-stripped water molecules to localize on the protein surface. PMID:23844874

  1. Ultrafast vibrational spectroscopy (2D-IR) of CO2 in ionic liquids: Carbon capture from carbon dioxide's point of view

    Science.gov (United States)

    Brinzer, Thomas; Berquist, Eric J.; Ren, Zhe; Dutta, Samrat; Johnson, Clinton A.; Krisher, Cullen S.; Lambrecht, Daniel S.; Garrett-Roe, Sean

    2015-06-01

    The CO2ν3 asymmetric stretching mode is established as a vibrational chromophore for ultrafast two-dimensional infrared (2D-IR) spectroscopic studies of local structure and dynamics in ionic liquids, which are of interest for carbon capture applications. CO2 is dissolved in a series of 1-butyl-3-methylimidazolium-based ionic liquids ([C4C1im][X], where [X]- is the anion from the series hexafluorophosphate (PF 6- ), tetrafluoroborate (BF 4- ), bis-(trifluoromethyl)sulfonylimide (Tf2N-), triflate (TfO-), trifluoroacetate (TFA-), dicyanamide (DCA-), and thiocyanate (SCN-)). In the ionic liquids studied, the ν3 center frequency is sensitive to the local solvation environment and reports on the timescales for local structural relaxation. Density functional theory calculations predict charge transfer from the anion to the CO2 and from CO2 to the cation. The charge transfer drives geometrical distortion of CO2, which in turn changes the ν3 frequency. The observed structural relaxation timescales vary by up to an order of magnitude between ionic liquids. Shoulders in the 2D-IR spectra arise from anharmonic coupling of the ν2 and ν3 normal modes of CO2. Thermal fluctuations in the ν2 population stochastically modulate the ν3 frequency and generate dynamic cross-peaks. These timescales are attributed to the breakup of ion cages that create a well-defined local environment for CO2. The results suggest that the picosecond dynamics of CO2 are gated by local diffusion of anions and cations.

  2. Ultrafast vibrational spectroscopy (2D-IR) of CO2 in ionic liquids: Carbon capture from carbon dioxide’s point of view

    International Nuclear Information System (INIS)

    The CO2ν3 asymmetric stretching mode is established as a vibrational chromophore for ultrafast two-dimensional infrared (2D-IR) spectroscopic studies of local structure and dynamics in ionic liquids, which are of interest for carbon capture applications. CO2 is dissolved in a series of 1-butyl-3-methylimidazolium-based ionic liquids ([C4C1im][X], where [X]− is the anion from the series hexafluorophosphate (PF6−), tetrafluoroborate (BF4−), bis-(trifluoromethyl)sulfonylimide (Tf2N−), triflate (TfO−), trifluoroacetate (TFA−), dicyanamide (DCA−), and thiocyanate (SCN−)). In the ionic liquids studied, the ν3 center frequency is sensitive to the local solvation environment and reports on the timescales for local structural relaxation. Density functional theory calculations predict charge transfer from the anion to the CO2 and from CO2 to the cation. The charge transfer drives geometrical distortion of CO2, which in turn changes the ν3 frequency. The observed structural relaxation timescales vary by up to an order of magnitude between ionic liquids. Shoulders in the 2D-IR spectra arise from anharmonic coupling of the ν2 and ν3 normal modes of CO2. Thermal fluctuations in the ν2 population stochastically modulate the ν3 frequency and generate dynamic cross-peaks. These timescales are attributed to the breakup of ion cages that create a well-defined local environment for CO2. The results suggest that the picosecond dynamics of CO2 are gated by local diffusion of anions and cations

  3. 1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled β-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes.

    Science.gov (United States)

    Ansari, Mohd Asif; Mandal, Abhishek; Paretzki, Alexa; Beyer, Katharina; Fiedler, Jan; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2016-06-01

    The dinuclear complexes {(μ-H2L)[Ru(bpy)2]2}(ClO4)2 ([3](ClO4)2), {(μ-H2L)[Ru(pap)2]2}(ClO4)2 ([4](ClO4)2), and the asymmetric [(bpy)2Ru(μ-H2L)Ru(pap)2](ClO4)2 ([5](ClO4)2) were synthesized via the mononuclear species [Ru(H3L)(bpy)2]ClO4 ([1]ClO4) and [Ru(H3L)(pap)2]ClO4 ([2]ClO4), where H4L is the centrosymmetric 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochemistry of the structurally characterized [1]ClO4, [2]ClO4, [3](ClO4)2, [4](ClO4)2, and [5](ClO4)2 reveals multistep oxidation and reduction processes, which were analyzed by electron paramagnetic resonance (EPR) of paramagnetic intermediates and by UV-vis-NIR spectro-electrochemistry. With support by time-dependent density functional theory (DFT) calculations the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 3(3+) versus largely bridge-centered spin in 4(3+)-a result of the presence of Ru(II)-stabilizig pap coligands. In addition to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asymmetric system 5(3+) with about equal contributions from a radical bridge formulation. In comparison to the analogues with the deprotonated 1,4-diaminoanthraquinone isomer the centrosymmetric H2L(2-) bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites.

  4. Use of starch and potato peel waste for perchlorate bioreduction in water.

    Science.gov (United States)

    Okeke, Benedict C; Frankenberger, William T

    2005-07-15

    The cost of carbon substrates for microbial reduction of perchlorate (ClO(4)(-)) is central to the success and competitiveness of a sustainable bioremediation strategy for ClO(4)(-). This study explored the potential application of starch in combination with an amylolytic bacterial consortia and potato peel waste for ClO(4)(-) bioreduction. We obtained a potent amylolytic bacterial consortium that consisted of a Citrobacter sp. S4, Streptomyces sp. S2, Flavobacterium sp. S6, Pseudoxanthomonas sp. S5, Streptomyces sp. S7, and an Aeromonas sp. S8 identified by 16S rDNA sequencing. ClO(4)(-) concentration substantially decreased in purified starch medium inoculated with the amylolytic bacterial consortium and Dechlorosoma sp. perclace. Potato peel waste supported ClO(4)(-) reduction by perclace with the rate of ClO(4)(-) reduction being dependent on the amount of potato peels. Over 90% ClO(4)(-) removal was achieved in 4 days in a single time point experiment with 2% (w/v) potato peels waste. ClO(4)(-) reduction in a non-sterile 0.5% potato peel media inoculated with perclace occurred with an initial concentration of 10.14+/-0.04 mg L(-1) to 2.87+/-0.4 mg L(-1) (71.7% reduction) within 5 days. ClO(4)(-) was not detected in the cultures in 6 days. In a non-sterile 0.5% potato media without perclace, ClO(4)(-) depletion occurred slowly from an initial value of 9.99+/-0.15 mg L(-1) to 6.33+/-0.43 mg L(-1) (36.63% reduction) in 5 days. Thereafter, ClO(4)(-) was rapidly degraded achieving 77.1% reduction in 7 days and not detected in 9 days. No susbstantial reduction of ClO(4)(-) was observed in the sterile potato peel media without perclace in 7 days. Redox potential of the potato peel cultures was favorable for ClO(4)(-) reduction, decreasing to as low as -294 mV in 24 h. Sugar levels remained very low in cultures effectively reducing ClO(4)(-) and was substantially higher in sterilized controls. Our results indicate that potato peel waste in combination with amylolytic microorganisms and Dechlorosoma sp. perclace can be economically used to achieve complete ClO(4)(-) removal from water.

  5. Use of starch and potato peel waste for perchlorate bioreduction in water.

    Science.gov (United States)

    Okeke, Benedict C; Frankenberger, William T

    2005-07-15

    The cost of carbon substrates for microbial reduction of perchlorate (ClO(4)(-)) is central to the success and competitiveness of a sustainable bioremediation strategy for ClO(4)(-). This study explored the potential application of starch in combination with an amylolytic bacterial consortia and potato peel waste for ClO(4)(-) bioreduction. We obtained a potent amylolytic bacterial consortium that consisted of a Citrobacter sp. S4, Streptomyces sp. S2, Flavobacterium sp. S6, Pseudoxanthomonas sp. S5, Streptomyces sp. S7, and an Aeromonas sp. S8 identified by 16S rDNA sequencing. ClO(4)(-) concentration substantially decreased in purified starch medium inoculated with the amylolytic bacterial consortium and Dechlorosoma sp. perclace. Potato peel waste supported ClO(4)(-) reduction by perclace with the rate of ClO(4)(-) reduction being dependent on the amount of potato peels. Over 90% ClO(4)(-) removal was achieved in 4 days in a single time point experiment with 2% (w/v) potato peels waste. ClO(4)(-) reduction in a non-sterile 0.5% potato peel media inoculated with perclace occurred with an initial concentration of 10.14+/-0.04 mg L(-1) to 2.87+/-0.4 mg L(-1) (71.7% reduction) within 5 days. ClO(4)(-) was not detected in the cultures in 6 days. In a non-sterile 0.5% potato media without perclace, ClO(4)(-) depletion occurred slowly from an initial value of 9.99+/-0.15 mg L(-1) to 6.33+/-0.43 mg L(-1) (36.63% reduction) in 5 days. Thereafter, ClO(4)(-) was rapidly degraded achieving 77.1% reduction in 7 days and not detected in 9 days. No susbstantial reduction of ClO(4)(-) was observed in the sterile potato peel media without perclace in 7 days. Redox potential of the potato peel cultures was favorable for ClO(4)(-) reduction, decreasing to as low as -294 mV in 24 h. Sugar levels remained very low in cultures effectively reducing ClO(4)(-) and was substantially higher in sterilized controls. Our results indicate that potato peel waste in combination with amylolytic microorganisms and Dechlorosoma sp. perclace can be economically used to achieve complete ClO(4)(-) removal from water. PMID:16084965

  6. 1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled β-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes.

    Science.gov (United States)

    Ansari, Mohd Asif; Mandal, Abhishek; Paretzki, Alexa; Beyer, Katharina; Fiedler, Jan; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2016-06-01

    The dinuclear complexes {(μ-H2L)[Ru(bpy)2]2}(ClO4)2 ([3](ClO4)2), {(μ-H2L)[Ru(pap)2]2}(ClO4)2 ([4](ClO4)2), and the asymmetric [(bpy)2Ru(μ-H2L)Ru(pap)2](ClO4)2 ([5](ClO4)2) were synthesized via the mononuclear species [Ru(H3L)(bpy)2]ClO4 ([1]ClO4) and [Ru(H3L)(pap)2]ClO4 ([2]ClO4), where H4L is the centrosymmetric 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochemistry of the structurally characterized [1]ClO4, [2]ClO4, [3](ClO4)2, [4](ClO4)2, and [5](ClO4)2 reveals multistep oxidation and reduction processes, which were analyzed by electron paramagnetic resonance (EPR) of paramagnetic intermediates and by UV-vis-NIR spectro-electrochemistry. With support by time-dependent density functional theory (DFT) calculations the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 3(3+) versus largely bridge-centered spin in 4(3+)-a result of the presence of Ru(II)-stabilizig pap coligands. In addition to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asymmetric system 5(3+) with about equal contributions from a radical bridge formulation. In comparison to the analogues with the deprotonated 1,4-diaminoanthraquinone isomer the centrosymmetric H2L(2-) bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites. PMID:27171539

  7. Effect of side-chain asymmetry on the intermolecular structure and order-disorder transition in alkyl-substituted polyfluorenes

    DEFF Research Database (Denmark)

    Knaapila, Matti; Stepanyan, R.; Torkkeli, M.;

    2016-01-01

    or below the average grafting distance). Calorimetry and x-ray scattering indicate the condition TODT(PF6)∼TODTbi(PF1−8) following the low grafting prediction. PF6 side chains coming from the alternating backbone layers appear as two separate layers with thickness H(PF6), whereas PF1-8 side chains...

  8. Treatment of Amiodarone-Induced Thyrotoxicosis Type 2 : A Randomized Clinical Trial

    NARCIS (Netherlands)

    Eskes, Silvia A.; Endert, Erik; Fliers, Eric; Geskus, Ronald B.; Dullaart, Robin P. F.; Links, Thera P.; Wiersinga, Wilmar M.

    2012-01-01

    Context: Amiodarone-induced thyrotoxicosis (AIT) type 2 is self-limiting in nature, but most physicians are reluctant to continue amiodarone. When prednisone fails to restore euthyroidism, possibly due to mixed cases of AIT type 1 and 2, perchlorate (ClO4) might be useful because ClO4 reduces the cy

  9. Molecular sieve supported ionic liquids as efficient adsorbent for CO2 capture

    OpenAIRE

    Yang Na; Wang Rui

    2015-01-01

    [NH3e-mim][BF4], [OHe-mim][BF4] and [HOEAm] were selected and supported onto molecular sieves NaY, USY, SAPO-34 and MCM-41, to prepare supported ionic liquids. It was found that [NH3e-mim][BF4]/NaY has excellent CO2 adsorption performance, with adsorption capacity of 0.108 mmolCO2/g. This paper investigates the optimal adsorption conditions and recyclability of [NH3e-mim][BF4]/NaY. The results show that [NH3e-mim][BF4]/NaY has good CO2 adsorption under the ...

  10. Determination of three physical properties of quinoline ionic liquids with hexafluorophosphate

    OpenAIRE

    Tang Dan; Wang Litao; Yao Shun; Chen Yanwen; Wang Daocai; Song Hang

    2016-01-01

    Densities of one acidic ionic liquid (IL) Quinolinum hexafluorophosphate ([HBpy][PF6]), and four neutral dicationic ionic liquids (ILs) based on quinoline and hexafluoro-phosphate and linked with poly(ethylene glycol) (PEG): ([PEG200-DIL][PF6]2, [PEG400-DIL][PF6]2, [PEG800-DIL][PF6]2 and [PEG1000-DIL][PF6]2) were determined. In addition, the solubilities of six ILs in six lower alcohols, water, acetonitrile and diethyl ether were measured at 288.15 K; and the hydroscopicity of above five ILs ...

  11. Perchlorate content of plant foliage reflects a wide range of species-dependent accumulation but not ozone-induced biosynthesis

    International Nuclear Information System (INIS)

    Perchlorate (ClO4−) interferes with uptake of iodide in humans. Emission inventories do not explain observed distributions. Ozone (O3) is implicated in the natural origin of ClO4−, and has increased since pre-industrial times. O3 produces ClO4−in vitro from Cl−, and plant tissues contain Cl− and redox reactions. We hypothesize that O3 exposure may induce plant synthesis of ClO4−. We exposed contrasting crop species to environmentally relevant O3 concentrations. In the absence of O3 exposure, species exhibited a large range of ClO4− accumulation but there was no relationship between leaf ClO4− and O3, whether expressed as exposure or cumulative flux (dose). Older, senescing leaves accumulated more ClO4− than younger leaves. O3 exposed vegetation is not a source of environmental ClO4−. There was evidence of enhanced ClO4− content in the soil surface at the highest O3 exposure, which could be a significant contributor to environmental ClO4−. -- Highlights: • Exposure to ozone in crop species does not induce accumulation nor biosynthesis of perchlorate. • Older leaves accumulate more perchlorate than younger leaves. • Soil surface may accumulate perchlorate following exposure to ozone. • Species differ greatly in accumulation of perchlorate from the rhizosphere, independent of ozone. • Ozone exposed vegetation is not a candidate source of environmental perchlorate. -- Exposure of crop species to ozone did not lead to biosynthesis or greater accumulation of foliar perchlorate. Older leaves accumulated more perchlorate than younger leaves

  12. Heteropolyhedral silver compounds containing the polydentate ligand N,N,O-E-[6-(hydroxyimino)ethyl]-1,3,7-trimethyllumazine. Preparation, spectral and XRD structural study and AIM calculations.

    Science.gov (United States)

    Jiménez-Pulido, Sonia B; Hueso-Ureña, Francisco; Fernández-Liencres, M Paz; Fernández-Gómez, Manuel; Moreno-Carretero, Miguel N

    2013-01-14

    The oxime derived from 6-acetyl-1,3,7-trimethyllumazine (1) ((E-6-(hydroxyimino)ethyl)-1,3,7-trimethylpteridine-2,4(1H,3H)-dione, DLMAceMox) has been prepared and its molecular and crystal structure determined from spectral and XRD data. The oxime ligand was reacted with silver nitrate, perchlorate, thiocyanate, trifluoromethylsulfonate and tetrafluoroborate to give complexes with formulas [Ag(2)(DLMAceMox)(2)(NO(3))(2)](n) (2), [Ag(2)(DLMAceMox)(2)(ClO(4))(2)](n) (3), [Ag(2)(DLMAceMox)(2)(SCN)(2)] (4), [Ag(2)(DLMAceMox)(2)(CF(3)SO(3))(2)(CH(3)CH(2)OH)]·CH(3)CH(2)OH (5) and [Ag(DLMAceMox)(2)]BF(4) (6). Single-crystal XRD studies show that the asymmetrical residual unit of complexes 2, 3 and 5 contains two quite different but connected silver centers (Ag1-Ag2, 2.9-3.2 Å). In addition to this, the Ag1 ion displays coordination with the N5 and O4 atoms from both lumazine moieties and a ligand (nitrato, perchlorato or ethanol) bridging to another disilver unit. The Ag2 ion is coordinated to the N61 oxime nitrogens, a monodentate and a (O,O)-bridging nitrato/perchlorato or two monodentate O-trifluoromethylsulfonato anions. The coordination polyhedra can be best described as a strongly distorted octahedron (around Ag1) and a square-based pyramid (around Ag2). The Ag-N and Ag-O bond lengths range between 2.22-2.41 and 2.40-2.67 Å, respectively. Although the structure of 4 cannot be resolved by XRD, it is likely to be similar to those described for 2, 3 and 5, containing Ag-Ag units with S-thiocyanato terminal ligands. Finally, the structure of the tetrafluoroborate compound 6 is mononuclear with a strongly distorted tetrahedral AgN(4) core (Ag-N, 2.27-2.43 Å). Always, the different Ag-N distances found clearly point to the more basic character of the oxime N61 nitrogen atom when compared with the pyrazine N5 one. A topological analysis of the electron density within the framework provided by the quantum theory of atoms in molecules (QTAIM) using DFT(M06L) levels of

  13. Developing New Electrolytes for Advanced Li-ion Batteries

    Science.gov (United States)

    McOwen, Dennis Wayne

    synthesized for this investigation: dilithium 1,2,5-thiadiazolidine-3,4-dione-1,1-dioxide (Li2TDD), lithium ethyl N-trifluoroacetylcarbamate (LiETAC), lithium hexafluoroisopropoxide (LiHFI), lithium pentafluorophenolate (LiPFPO), and lithium 2-trifluoromethyl-4,5-dicyanoimidazolide (LiTDI). Using crystalline solvate structure analysis and electrolyte solvation numbers, each of these lithium salts were compared to more well-characterized lithium salts, such as LiPF6 and LiBF4. From this study, links between anion structural characteristics and the anion...Li+ cation interactions (i.e., ionic association strength) were made. From the screening of the five lithium salts that were synthesized, LiTDI was determined to be a promising candidate for Li-ion battery electrolytes. Further characterization of carbonate- and mixed carbonate-LiTDI electrolytes (e.g., ionic conductivity) confirmed this to be the case. Coin cells containing LiTDI or LiPF6 electrolytes showed that cells with either electrolyte could deliver nearly identical power density at 25 °C. Additionally, thermogravimetric analysis (TGA) and NMR suggested that the LiTDI salt and carbonate-LiTDI electrolytes are thermally stable up to at least 60 °C. Further supporting this finding, coin cells cycled at 60 °C with LiPF6 lost significantly more capacity than those with LiTDI. Therefore, LiTDI is a prime candidate for the complete replacement of LiPF6 to significantly increase Li-ion battery tolerance to heat, improving the safety characteristics. In addition to searching for new lithium salts, the effect of lithium salt concentration on electrolyte physicochemical properties was investigated. This radically different approach to modifying electrolyte properties determined that amorphous, highly concentrated carbonate-lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolytes have drastically different behavior than more dilute electrolytes. For example, the thermal stability and anodic stability vs. a Pt

  14. Performance analysis of absorption heat transformer cycles using ionic liquids based on imidazolium cation as absorbents with 2,2,2-trifluoroethanol as refrigerant

    International Nuclear Information System (INIS)

    Highlights: • TFE + [emim][BF4] (or [bmim][BF4]) absorption heat transformer cycles are studied. • Influence of various operating conditions on cycle’s performance is investigated. • Performance comparisons with H2O + LiBr and TFE + TEGDME cycles are done. • Enthalpy data for TFE + [emim][BF4] (or [bmim][BF4]) liquid mixtures are calculated. • TFE + [emim][BF4] (or [bmim][BF4]) cycles have higher gross temperature lift (GTL). - Abstract: A detailed thermodynamic performance analysis of a single-stage absorption heat transformer and double absorption heat transformer cycles using new working pairs composed of ionic liquids (1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4])) as absorbent and 2,2,2-trifluoroethanol (TFE) as refrigerant has been studied. Several performance indicators were used to evaluate and compare the performance of the cycles using the TFE + [emim][BF4] and TFE + [bmim][BF4] working pairs with the conventional H2O + LiBr and organic TFE + TEGDME working pairs. The obtained results show that the ionic liquid based working pairs are suitable candidates to replace the conventional H2O + LiBr working pairs in order to avoid the disadvantages associated with it mainly crystallization and corrosion and also they perform better (higher gross temperature lift) than TFE + TEGDME working pair at several operating conditions considered in this work

  15. Temporal and spatial variation of perchlorate in streambed sediments: results from in-situ dialysis samplers

    International Nuclear Information System (INIS)

    The fate of perchlorate (ClO4-) in streambed sediments is becoming a concern due to the increasing number of groundwater and surface water contamination sites in the United States. Dialysis samplers were deployed at three sites over a period of 1 year to determine the vertical distribution of ClO4-in sediment pore water. Results indicated that the spatial and temporal ClO4-penetration into sediments could be affected by numerous factors, such as temperature, microbial degradation, ClO4-surface water concentration, and sediment physico-geological properties. In general, maximum ClO4-penetration into sediments at the studied sites was 30 cm below the sediment-water surface. The vertical sequential depletion of electron acceptors in sediments suggested that microbial reduction was responsible for ClO4-depletion in stream sediments. Biodegradation of ClO4-occurred over a seasonally variable active depth zone of 1-10 cm. Results implied that there was a rapid natural attenuation potential of perchlorate in saturated near-surface sediments. -Perchlorate may be rapidly attenuated in saturated near-surface sediments

  16. Perchlorate in Lake Water from an Operating Diamond Mine.

    Science.gov (United States)

    Smith, Lianna J D; Ptacek, Carol J; Blowes, David W; Groza, Laura G; Moncur, Michael C

    2015-07-01

    Mining-related perchlorate [ClO4(-)] in the receiving environment was investigated at the operating open-pit and underground Diavik diamond mine, Northwest Territories, Canada. Samples were collected over four years and ClO4(-) was measured in various mine waters, the 560 km(2) ultraoligotrophic receiving lake, background lake water and snow distal from the mine. Groundwaters from the underground mine had variable ClO4(-) concentrations, up to 157 μg L(-1), and were typically an order of magnitude higher than concentrations in combined mine waters prior to treatment and discharge to the lake. Snow core samples had a mean ClO4(-) concentration of 0.021 μg L(-1) (n=16). Snow and lake water Cl(-)/ClO4(-) ratios suggest evapoconcentration was not an important process affecting lake ClO4(-) concentrations. The multiyear mean ClO4(-) concentrations in the lake were 0.30 μg L(-1) (n = 114) in open water and 0.24 μg L(-1) (n = 107) under ice, much below the Canadian drinking water guideline of 6 μg L(-1). Receiving lake concentrations of ClO4(-) generally decreased year over year and ClO4(-) was not likely [biogeo]chemically attenuated within the receiving lake. The discharge of treated mine water was shown to contribute mining-related ClO4(-) to the lake and the low concentrations after 12 years of mining were attributed to the large volume of the receiving lake.

  17. Close Columnar Packing of Triangulenium Ions in Langmuir Films

    DEFF Research Database (Denmark)

    Simonsen, Jens B.; Kjær, Kristian; Howes, Paul;

    2009-01-01

    (GIXD). Compounds 5a center dot PF6 and 5b center dot PF6 both self-assemble into 2D-crystalline Langmuir monolayers, in which the planar triangular shaped carbenium ions form columnar aggregates segregated from the PF6- ions. The column width is found to be close to the width of the triangulenium......Three new tris(dialkylamino)trioxatriangulenium (ATOTA(+)) salts rendered amphiphilic by attachment of two (5a center dot PF6 and 5b center dot PF6) or four (5c center dot PF6) n-decyl chains have been synthesized, and their Langmuir films have been studied by grazing incidence X-ray diffraction...

  18. The electrochemistry of arylated anthraquinones in room temperature ionic liquids

    OpenAIRE

    Gomis Berenguer, Alicia; Gómez Mingot, María; García Cruz, Leticia; Thiemann, Thies; Banks, Craig E.; Montiel Leguey, Vicente; Iniesta Valcárcel, Jesús

    2013-01-01

    Arylated anthraquinone derivatives of different sizes and different π-basicities have been prepared, and the electrochemical behaviour of these substances has been studied on screen printed graphite electrodes in the three room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]), 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) and 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]). Half redox potentials for the first and...

  19. The base-catalyzed H/D--exchange of anisole moiety of ruthenium complex in cooperation with demethylation by hydroxide anion in methanol-d4

    International Nuclear Information System (INIS)

    [Ru (η5-C5H5)(η6-arene A)]BF4 (arene A = nitrobenzene, m- or p-nitrotoluene, anisole, phenetole, m- or p-methylanisole) were quantitatively converted to pure [Ru(η5-C5H5)(η-arene B)]BF4 (arene B = phenoxido-2d, m- or p-monodeuterated methylphenoxido) in the presence of excess KOH in CD3OD, whereas [Ru(η5-C5H5)(η6-anisole)]BF4 was quantitatively obtained by treatment [Ru(η5-C5H5)(η6-nitrobenzene)]BF4 with 1 equivalent KOH or CH3OK. (author)

  20. Fluorescence quenching of coumarin 153 by hydroxyl-functionalized room temperature ionic liquids

    Science.gov (United States)

    Li, Shuang; Yu, Anchi; Lu, Rong

    2016-08-01

    Steady-state absorption and fluorescence as well as time-resolved fluorescence of coumarin 151 (C151) and coumarin 153 (C153) were measured in hydroxyl-functionalized ionic liquids ([HOEmim][BF4] and [HOEmim][N(CN)2]) and in nonhydroxyl-functionalized ionic liquids ([Emim][BF4] and [Emim][N(CN)2]). Both the steady-state fluorescence and time-resolved fluorescence observations reveal that hydroxyl-functionalized ionic liquid quenches the fluorescence of C153 while the nonhydroxyl-functionalized ionic liquid does not. We also measured the time-resolved fluorescence anisotropy of C151 and C153 in both [HOEmim][BF4] and [Emim][BF4]. It is found that the ratio of the rotational relaxation lifetime of C153 in [HOEmim][BF4] with respect to that in [Emim][BF4] is about 15% larger than that of C151 in [HOEmim][BF4] with respect to that in [Emim][BF4], indicating extra interaction between C153 and [HOEmim][BF4] exists except the effect of the viscosity of ionic liquid.

  1. Local Structure in Terms of Nearest-Neighbor Approach in 1-Butyl-3-methylimidazolium-Based Ionic Liquids: MD Simulations.

    Science.gov (United States)

    Marekha, Bogdan A; Koverga, Volodymyr A; Chesneau, Erwan; Kalugin, Oleg N; Takamuku, Toshiyuki; Jedlovszky, Pál; Idrissi, Abdenacer

    2016-06-01

    Description of the local microscopic structure in ionic liquids (ILs) is a prerequisite to obtain a comprehensive understanding of the influence of the nature of ions on the properties of ILs. The local structure is mainly determined by the spatial arrangement of the nearest neighboring ions. Therefore, the main interaction patterns in ILs, such as cation-anion H-bond-like motifs, cation-cation alkyl tail aggregation, and ring stacking, were considered within the framework of the nearest-neighbor approach with respect to each particular interaction site. We employed classical molecular dynamics (MD) simulations to study in detail the spatial, radial, and orientational relative distribution of ions in a set of imidazolium-based ILs, in which the 1-butyl-3-methylimidazolium (C4mim(+)) cation is coupled with the acetate (OAc(-)), chloride (Cl(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)), trifluoromethanesulfonate (TfO(-)), or bis(trifluoromethanesulfonyl)amide (TFSA(-)) anion. It was established that several structural properties are strongly anion-specific, while some can be treated as universally applicable to ILs, regardless of the nature of the anion. Namely, strongly basic anions, such as OAc(-) and Cl(-), prefer to be located in the imidazolium ring plane next to the C-H(2/4-5) sites. By contrast, the other four bulky and weakly coordinating anions tend to occupy positions above/below the plane. Similarly, the H-bond-like interactions involving the H(2) site are found to be particularly enhanced in comparison with the ones at H(4-5) in the case of asymmetric and/or more basic anions (C4mimOAc, C4mimCl, C4mimTfO, and C4mimTFSA), in accordance with recent spectroscopic and theoretical findings. Other IL-specific details related to the multiple H-bond-like binding and cation stacking issues are also discussed in this paper. The secondary H-bonding of anions with the alkyl hydrogen atoms of cations as well as the cation-cation alkyl chain

  2. Derivation of structure-activity relationships from the anticancer properties of ruthenium(II) arene complexes with 2-aryldiazole ligands.

    Science.gov (United States)

    Martínez-Alonso, Marta; Busto, Natalia; Jalón, Félix A; Manzano, Blanca R; Leal, José M; Rodríguez, Ana M; García, Begoña; Espino, Gustavo

    2014-10-20

    The ligands 2-pyridin-2-yl-1H-benzimidazole (HL(1)), 1-methyl-2-pyridin-2-ylbenzimidazole (HL(2)), and 2-(1H-imidazol-2-yl)pyridine (HL(3)) and the proligand 2-phenyl-1H-benzimidazole (HL(4)) have been used to prepare five different types of new ruthenium(II) arene compounds: (i) monocationic complexes with the general formula [(η(6)-arene)RuCl(κ(2)-N,N-HL)]Y [HL = HL(1), HL(2), or HL(3); Y = Cl or BF4; arene = 2-phenoxyethanol (phoxet), benzene (bz), or p-cymene (p-cym)]; (ii) dicationic aqua complexes of the formula [(η(6)-arene)Ru(OH2)(κ(2)-N,N-HL(1))](Y)2 (Y = Cl or TfO; arene = phoxet, bz, or p-cym); (iii) the nucleobase derivative [(η(6)-arene)Ru(9-MeG)(κ(2)-N,N-HL(1))](PF6)2 (9-MeG = 9-methylguanine); (iv) neutral complexes consistent with the formulation [(η(6)-arene)RuCl(κ(2)-N,N-L(1))] (arene = bz or p-cym); (v) the neutral cyclometalated complex [(η(6)-p-cym)RuCl(κ(2)-N,C-L(4))]. The cytototoxic activity of the new ruthenium(II) arene compounds has been evaluated in several cell lines (MCR-5, MCF-7, A2780, and A2780cis) in order to establish structure-activity relationships. Three of the compounds with the general formula [(η(6)-arene)RuCl(κ(2)-N,N-HL(1))]Cl differing in the arene moiety have been studied in depth in terms of thermodynamic dissociation constants, aquation kinetic constants, and DNA binding measurements. The biologically most active compound is the p-cym derivative, which strongly destabilizes the DNA double helix, whereas those with bz and phoxet have only a small effect on the stability of the DNA double helix. Moreover, the inhibitory activity of several compounds toward CDK1 has also been evaluated. The DNA binding ability of some of the studied compounds and their CDK1 inhibitory effect suggest a multitarget mechanism for their biological activity. PMID:25302401

  3. Ionic liquids for nano- and microstructures preparation. Part 2: Application in synthesis.

    Science.gov (United States)

    Łuczak, Justyna; Paszkiewicz, Marta; Krukowska, Anna; Malankowska, Anna; Zaleska-Medynska, Adriana

    2016-01-01

    Ionic liquids (ILs) are widely applied to prepare metal nanoparticles and 3D semiconductor microparticles. Generally, they serve as a structuring agent or reaction medium (solvent), however it was also demonstrated that ILs can play a role of a co-solvent, metal precursor, reducing as well as surface modifying agent. The crucial role and possible types of interactions between ILs and growing particles have been presented in the Part 1 of this review paper. Part 2 of the paper gives a comprehensive overview of recent experimental studies dealing with application of ionic liquids for preparation of metal and semiconductor based nano- and microparticles. A wide spectrum of preparation routes using ionic liquids is presented, including precipitation, sol-gel technique, hydrothermal method, nanocasting and ray-mediated methods (microwave, ultrasound, UV-radiation and γ-radiation). It was found that ionic liquids formed of a 1-butyl-3-methylimidazolium [BMIM] combined with tetrafluoroborate [BF4], hexafluorophosphate [PF6], and bis(trifluoromethanesulfonyl)imide [Tf2N] are the most often used ILs in the synthesis of nano- and microparticles, due to their low melting temperature, low viscosity and good transportation properties. Nevertheless, examples of other IL classes with intrinsic nanoparticles stabilizing abilities such as phosphonium and ammonium derivatives are also presented. Experimental data revealed that structure of ILs (both anion and cation type) affects the size and shape of formed metal particles, and in some cases may even determine possibility of particles formation. The nature of the metal precursor determines its affinity to polar or nonpolar domains of ionic liquid, and therefore, the size of the nanoparticles depends on the size of these regions. Ability of ionic liquids to form varied extended interactions with particle precursor as well as other compounds presented in the reaction media (water, organic solvents etc.) provides nano- and

  4. ANALYSIS OF HYDROPONIC FERTILIZER MATRIXES FOR PERCHLORATE: COMPARISON OF ANALYTICAL TECHNIQUES

    Science.gov (United States)

    Seven retail hydroponic nitrate fertilizer products, two liquid and five solid, were comparatively analyzed for the perchlorate anion (ClO4-) by ion chromatography (IC) with suppressed conductivity detection, complexation electrospray ionization mass spectrometry (cESI-MS), norma...

  5. Soil, plant, and terrain effects on natural perchlorate distribution in a desert landscape

    Science.gov (United States)

    Andraski, Brian J.; Jackson, W.A.; Welborn, Toby L.; Böhlke, John Karl; Sevanthi, Ritesh; Stonestrom, David A.

    2014-01-01

    Perchlorate (ClO4−) is a contaminant that occurs naturally throughout the world, but little is known about its distribution and interactions in terrestrial ecosystems. The objectives of this Amargosa Desert, Nevada study were to determine (i) the local-scale distribution of shallow-soil (0–30 cm) ClO4− with respect to shrub proximity (far and near) in three geomorphic settings (shoulder slope, footslope, and valley floor); (ii) the importance of soil, plant, and terrain variables on the hillslope-distribution of shallow-soil and creosote bush [Larrea tridentata (Sessé & Moc. ex DC.) Coville] ClO4−; and (iii) atmospheric (wet plus dry, including dust) deposition of ClO4− in relation to soil and plant reservoirs and cycling. Soil ClO4− ranged from 0.3 to 5.0 μg kg−1. Within settings, valley floor ClO4− was 17× less near shrubs due in part to enhanced leaching, whereas shoulder and footslope values were ∼2× greater near shrubs. Hillslope regression models (soil, R2 = 0.42; leaf, R2 = 0.74) identified topographic and soil effects on ClO4− deposition, transport, and cycling. Selective plant uptake, bioaccumulation, and soil enrichment were evidenced by leaf ClO4− concentrations and Cl−/ClO4− molar ratios that were ∼8000× greater and 40× less, respectively, than soil values. Atmospheric deposition ClO4− flux was 343 mg ha−1 yr−1, ∼10× that for published southwestern wet-deposition fluxes. Creosote bush canopy ClO4− (1310 mg ha−1) was identified as a previously unrecognized but important and active reservoir. Nitrate δ18O analyses of atmospheric deposition and soil supported the leaf-cycled–ClO4− input hypothesis. This study provides basic data on ClO4− distribution and cycling that are pertinent to the assessment of environmental impacts in desert ecosystems and broadly transferable to anthropogenically contaminated systems.

  6. Manganese (III) cyclam complexes with aqua, iodo, nitrito, perchlorato and acetic acid/acetato axial ligands

    DEFF Research Database (Denmark)

    Mossin, Susanne; Sørensen, Henning Osholm; Weihe, Høgni;

    2005-01-01

    The syntheses, structures and magnetic properties of five new manganese (III) cyclam complexes, trans-[Mn(cyclam)(OH2)(2)]-(CF3SO3)(3)center dot-H2O, trans-[Mn(cyclam)I-2]I, trans-[Mn(cyclam)(ONO)(2)]ClO4, trans-[Mn(cyclam)(OClO3)(2)]ClO4 and trans-[Mn(cyclam) (CH3COO)(CH3COOH)](ClO4)(2), are rep...

  7. Analysis of Redox Series of Unsymmetrical 1,4-Diamido-9,10-anthraquinone-Bridged Diruthenium Compounds.

    Science.gov (United States)

    Mandal, Abhishek; Hoque, Md Asmaul; Grupp, Anita; Paretzki, Alexa; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2016-03-01

    The unsymmetrical diruthenium complexes [(bpy)2Ru(II)(μ-H2L(2-))Ru(III)(acac)2]ClO4 ([3]ClO4), [(pap)2RuII(μ-H2L(2-))Ru(III)(acac)2]ClO4 ([4]ClO4), and [(bpy)2Ru(II)(μ-H2L(2-))Ru(II)(pap)2](ClO4)2 ([5](ClO4)2) have been obtained by way of the mononuclear precursors [(bpy)2Ru(II)(H3L(-))]ClO4 ([1]ClO4) and [(pap)2Ru(II)(H3L(-))]ClO4 ([2]ClO4) (where bpy = 2,2′-bipyridine, pap = 2-phenylazopyridine, acac(-) = 2,4-pentanedionate, and H4L = 1,4-diamino-9,10-anthraquinone). Structural characterization by single-crystal X-ray diffraction and magnetic resonance (nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR)) were used to establish the oxidation state situation in each of the isolated materials. Cyclic voltammetry, EPR, and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroelectrochemistry were used to analyze the multielectron transfer series of the potentially class I mixed-valent dinuclear compounds, considering the redox activities of differently coordinated metals, of the noninnocent bridge and of the terminal ligands. Comparison with symmetrical analogues [L2′Ru(μ-H2L)RuL2′](n) (where L′ = bpy, pap, or acac(-)) shows that the redox processes in the unsymmetrical dinuclear compounds are not averaged, with respect to the corresponding symmetrical systems, because of intramolecular charge rearrangements involving the metals, the noninnocent bridge, and the ancillary ligands. PMID:26887785

  8. Varying Electronic Structures of Diosmium Complexes from Noninnocently Behaving Anthraquinone-Derived Bis-chelate Ligands.

    Science.gov (United States)

    Mandal, Abhishek; Grupp, Anita; Schwederski, Brigitte; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2015-08-17

    The new compounds [(bpy)2Os(II)(μ-L1(2-))Os(II)(bpy)2](ClO4)2 ([1](ClO4)2) and [(pap)2Os(II)(μ-L1(2-))Os(II)(pap)2](ClO4)2 ([2](ClO4)2) (H2L1 = 1,4-dihydroxy-9,10-anthraquinone, bpy = 2,2(/)-bipyridine, and pap = 2-phenylazopyridine) and [(bpy)2Os(II)(μ-L2(•-))Os(II)(bpy)2](ClO4)3 ([3](ClO4)3) and [(pap)2Os(II)(μ-L2(2-))Os(II)(pap)2](ClO4)2 ([4](ClO4)2) (H2L2 = 1,4-diamino-9,10-anthraquinone) have been analytically identified as the meso and rac diastereoisomers, respectively. The paramagnetic [3](ClO4)3 was also characterized by crystal structure determination. In CD3CN solution, [3](ClO4)3 displays rather narrow but widely split (13 > δ > -8 ppm) resonances in the (1)H NMR spectrum, yet no EPR signal was observed down to 120 K. Cyclic voltammetry and differential pulse voltammetry reveal several accessible redox states on oxidation and reduction, showing that the replacement of 1,4-oxido by imido donors causes cathodic shifts and that the substitution of bpy by the stronger π-accepting pap ligands leads to a strong increase of redox potentials. Accordingly, system 3(n) with the lowest (2+/3+) potential was synthetically obtained in the mono-oxidized (3+) form. The (3+) intermediates display small comproportionation constants Kc of about 10(3) and long-wavelength near-infrared absorptions; an EPR signal with appreciable g splitting (1.84, 1.96, and 2.03) was only observed for 4(3+), which exhibits the smallest spin density on the osmium centers. An oxidation state formulation [Os(III)(μ-L(•3-))Os(III)](3+) with some [Os(II)(μ-L(2-))Os(III)](3+) contribution was found to best describe the electronic structures. UV-vis-NIR absorption spectra were recorded for all accessible states by OTTLE spectroelectrochemistry and assigned on the basis of TD-DFT calculations. These results and additional EPR measurements suggest rather variegated oxidation state situations, e.g., the pap ligands competing with the bridge L for electrons, while the oxidation produces mixed spin systems with variable metal/ligand contributions.

  9. Evidence of water-in-ionic liquid microemulsion formation by nonionic surfactant Brij-35.

    Science.gov (United States)

    Rai, Rewa; Pandey, Siddharth

    2014-09-01

    Brij-35, a common and popular nonionic surfactant, is shown to form water-in-ionic liquid (w/IL) microemulsions with IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) as the bulk phase. The presence of w/[bmim][PF6] microemulsions is hinted by the significantly increased solubility of water in Brij-35 solution of [bmim][PF6]. The formation of w/[bmim][PF6] microemulsions by Brij-35 is confirmed using dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS) measurements. Brij-35 forms reverse micelle-type aggregates within [bmim][PF6] in the absence of added-water. These reverse micelles become w/[bmim][PF6] microemulsions as the water is added to the system. As the water loading (w0) is increased, the average diameter of the aggregates increases. Fourier transform infrared (FTIR) absorbance data reveal the presence of both "bound" and "free" water within the system. The "bound" water is associated with the water pools of the w/[bmim][PF6] microemulsions. Excited-state proton transfer (ESPT) involving probe pyranine shows deprotonation of pyranine within the water pools of the w/[bmim][PF6] microemulsions. PMID:25121578

  10. Raman and ab initio studies of simple and binary 1-alkyl-3-methylimidazolium ionic liquids

    DEFF Research Database (Denmark)

    Berg, R.W.; Deetlefs, M.; Seddon, K.R.;

    2005-01-01

    Raman spectra of the ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF6]), 1-hexyl-3-methylimidazolium chloride ([C(6)mim]Cl), and 1-hexyl-3-methylimidazolium hexafluorophosphate ([C(6)mim][PF6]), and binary mixtures thereof, have been assigned using ab initio MP2...

  11. The role of salicylic acid, L-ascorbic acid and oxalic acid in promoting the oxidation of alkenes with H(2)O(2) catalysed by [Mn(IV) (2)(O)(3)(tmtacn)(2)](2+)

    NARCIS (Netherlands)

    de Boer, Johannes W.; Alsters, Paul L.; Meetsma, Auke; Hage, Ronald; Browne, Wesley R.; Feringa, Ben L.

    2008-01-01

    The role played by the additives salicylic acid, L-ascorbic acid and oxalic acid in promoting the catalytic activity of [Mn(IV) (2)(O)(3)(tmtacn)(2)](PF(6))(2) {1(PF(6))(2), where tmtacn = N, N ', N ''-trimethyl-1,4,7-triazacyclononane} in the epoxidation and cis-dihydroxylation of alkenes with H(2)

  12. 二茂铁四氟硼酸盐用作潜热阳离子引发剂对环氧树脂的热固化引发环氧化合物阳离子热聚合%Novel Ferricenium Tetrafluoroborate Salt as Latent Thermal Cationic Initiator for Curing of Epoxy Resins

    Institute of Scientific and Technical Information of China (English)

    王涛; 王志华; 刘金萍

    2004-01-01

    A novel latent thermal initiator, ferricenium tetrafiuoroborate salt (FcBF4), for cationic polymerization of epoxides is reported. The activities of FcBF4 for different epoxides, including bisphenol-A-type epoxy oligomer E44, cycloaliphatic epoxy ERL4221, and glycidylether epoxy GGE, were evaluated by differential scanning calorimetry (DSC). The results showed a moderate thermal initiation activity for E44 and GGE at 78℃ and 108℃respectively. When adding GGE to E44, the reaction was enhanced. The temperature of thermal degradation of the cured specimens for the system of E44/FcBF4, E44+10%GGE/FcBF4 and E44+10%ERL4221/FcBF4 is higher than 350℃.

  13. Novel Ferricenium Tetrafluoroborate Salt as Latent Thermal Cationic Initiator for Curing of Epoxy Resins

    Institute of Scientific and Technical Information of China (English)

    王涛; 王志华; 刘金萍

    2004-01-01

    A novel latent thermal initiator, ferricenium tetrafluoroborate salt (FcBF4), for cationic polymerization of epoxides is reported. The activities of FcBF4 for different epoxides, including bisphenol-A-type epoxy oligomer E44, cycloaliphatic epoxy ERL4221, and glycidylether epoxy GGE, were evaluated by differential scanning calorimetry (DSC). The results showed a moderate thermal initiation activity for E44 and GGE at 78℃ and 108℃ respectively. When adding GGE to E44, the reaction was enhanced. The temperature of thermal degradation of the cured specimens for the system of E44/FcBF4, E44+10%GGE/FcBF4 and E44+10%ERL4221/FcBF4 is higher than 350℃.

  14. Reactions of hydridoirida-β-diketones with amines or with 2-aminopyridines: formation of hydridoirida-β-ketoimines, PCN terdentate ligands, and acyl decarbonylation.

    Science.gov (United States)

    Ciganda, Roberto; Garralda, María A; Ibarlucea, Lourdes; Mendicute-Fierro, Claudio; Torralba, M Carmen; Torres, M Rosario

    2012-02-01

    The hydridoirida-β-diketone [IrHCl{(PPh(2)(o-C(6)H(4)CO))(2)H}] (1) reacts with benzylamine (C(6)H(5)CH(2)NH(2)) to give the hydridoirida-β-ketoimine [IrHCl{(PPh(2)(o-C(6)H(4)CO))(PPh(2)(o-C(6)H(4)CNCH(2)C(6)H(5)))H}] (2), stabilized by an intramolecular hydrogen bond. 2 reacts with water to undergo hydrolysis and amine coordination giving hydridodiacylamino [IrH(PPh(2)(o-C(6)H(4)CO))(2)(C(6)H(5)CH(2)NH(2))] (3). Cyclohexylamine or dimethylamine lead to hydridodiacylamino [IrH(PPh(2)(o-C(6)H(4)CO))(2)L] (4-5). In chlorinated solvents hydridodiacylamino complexes undergo exchange of hydride by chloride to afford [IrCl(PPh(2)(o-C(6)H(4)CO))(2)L] (6-9). The reaction of 1 with hydrazine (H(2)NNH(2)) gives hydridoirida-β-ketoimine [IrHCl{(PPh(2)(o-C(6)H(4)CO))(PPh(2)(o-C(6)H(4)CNNH(2)))H}] (10), fluxional in solution with values for ΔH(‡) of 2.5 ± 0.3 kcal mol(-1) and for ΔS(‡) of -32.9 ± 3 eu. A hydrolysis/imination sequence can be responsible for fluxionality. 2-Aminopyridines (RHNC(5)H(3)R'N) react with 1 to afford cis-[IrCl(PPh(2)(o-C(6)H(4)CO))(PPh(2)(o-C(6)H(4)CHNRC(5)H(3)R'N))] (R = R' = H (11), R = CH(3), R' = H (12), R = H, R' = CH(3) (13)) containing new terdentate PCN ligands in a facial disposition and cis phosphorus atoms as kinetic products. The formation of 11-13 requires imination of the hydroxycarbene moiety of 1, coordination of the nitrogen atom of pyridine to iridium, and iridium to carbon hydrogen transfer. In refluxing methanol, complexes 11-13 isomerize to afford the thermodynamic products 14-16 with trans phosphorus atoms. Chloride abstraction from complexes [IrCl(PPh(2)(o-C(6)H(4)CO))(PPh(2)(o-C(6)H(4)CHNRC(5)H(4)N))] (R = H or CH(3)) leads to decarbonylation of the acylphosphine chelating group to afford cationic complexes [Ir(CO)(PPh(2)(o-C(6)H(4)))(PPh(2)(o-C(6)H(4)CHNRC(5)H(4)N))]A, 17 (R = H, A = ClO(4)) and 18 (R = CH(3), A = BF(4)) as a cis/trans = 4:1 mixture of isomers. Single crystal X-ray diffraction analysis was performed

  15. Study of microbial perchlorate reduction: Considering of multiple pH, electron acceptors and donors

    International Nuclear Information System (INIS)

    Graphical abstract: Schemes of perchlorate reduction in ClO4−/ClO3−–NO3− e−acceptor systems. - Highlights: • We created a multiple electron acceptor/donor system for ClO4− reduction. • Nitrate reduction was inhibited when using perchlorate-grown Azospira sp. KJ. • Reduction proceeded as an order of ClO3−, ClO4−and NO3−. • Oxidation of acetate was inhibited by succinate in acetate–succinate series. - Abstract: Bioremediation of perchlorate-cotaminated water by a heterotrophic perchlorate reducing bacterium creates a multiple electron acceptor-donor system. We experimentally determined the perchlorate reduction by Azospira sp. KJ at multiple pH, electron acceptors and donors systems; this was the aim of this study. Perchlorate reduction was drastically inhibited at the pH 6.0, and the maximum reduction of perchlorate by Azospira sp. KJ was observed at pH value of 8.0. Perchlorate reduction was retarded in ClO4−–ClO3−, ClO4−–ClO3−–NO3−,and ClO4−–NO3− acceptor systems, while being completely inhibited by the additional O2 in the ClO4−–O2 acceptor system. The reduction proceeded as an order of ClO3−, ClO4−, and NO3− in the ClO4−–ClO3−–NO3− system. KS,vmax, and qmax obtained at different e− acceptor and donor conditions are calculated as 140.5–190.6 mg/L, 8.7–13.2 mg-perchlorate/L-h, and 0.094–0.16 mg-perchlorate/mg-DW-h, respectively

  16. Crystal structures of Ca(ClO42·4H2O and Ca(ClO42·6H2O

    Directory of Open Access Journals (Sweden)

    Erik Hennings

    2014-12-01

    Full Text Available The title compounds, calcium perchlorate tetrahydrate and calcium perchlorate hexahydrate, were crystallized at low temperatures according to the solid–liquid phase diagram. The structure of the tetrahydrate consists of one Ca2+ cation eightfold coordinated in a square-antiprismatic fashion by four water molecules and four O atoms of four perchlorate tetrahedra, forming chains parallel to [01-1] by sharing corners of the ClO4 tetrahedra. The structure of the hexahydrate contains two different Ca2+ cations, each coordinated by six water molecules and two O atoms of two perchlorate tetrahedra, forming [Ca(H2O6(ClO4]2 dimers by sharing two ClO4 tetrahedra. The dimers are arranged in sheets parallel (001 and alternate with layers of non-coordinating ClO4 tetrahedra. O—H...O hydrogen bonds between the water molecules as donor and ClO4 tetrahedra and water molecules as acceptor groups lead to the formation of a three-dimensional network in the two structures. Ca(ClO42·6H2O was refined as a two-component inversion twin, with an approximate twin component ratio of 1:1 in each of the two structures.

  17. The effect of ionic liquid hydrophobicity and solvent miscibility on pluronic amphiphile self-assembly.

    Science.gov (United States)

    Sharma, Suraj Chandra; Atkin, Rob; Warr, Gregory G

    2013-11-21

    The phase behavior of the triblock copolymer, (EO)20(PO)70(EO)20 (P123), in the water-immiscible (hydrophobic) ionic liquids (ILs), 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6), and tris(pentafluoroethyl)trifluorophosphate (bmimFAP), has been investigated, and its amphiphilic self-assembly examined using small-angle X-ray scattering. The results obtained are contrasted with those for P123 in water. Direct and water-swellable micellar, hexagonal, and lamellar phases of P123 are found in bmimPF6, which behaves like a polar solvent despite being water immiscible, but bmimFAP behaves as a truly hydrophobic solvent, forming only a lamellar phase over a narrow composition range. The miscibility of bmimPF6 and water is increased by P123 addition, and at sufficiently high P123 concentrations, a single lamellar phase forms in which bmimPF6 and water are miscible in all proportions. In contrast, the preferential solubilization of bmimPF6 by PEO chains and bmimFAP by PPO chains causes the nanosegregation of these miscible ILs in concentrated P123 solutions. This leads to the formation of a P123/bmimPF6/bmimFAP microemulsion where bmimPF6 is the polar solvent and bmimFAP is the non-polar solvent. PMID:24138343

  18. Chemical Swarming: Depending on Concentration, an Amphiphilic Ruthenium Polypyridyl Complex Induces Cell Death via Two Different Mechanisms.

    Science.gov (United States)

    Siewert, Bianka; van Rixel, Vincent H S; van Rooden, Eva J; Hopkins, Samantha L; Moester, Miriam J B; Ariese, Freek; Siegler, Maxime A; Bonnet, Sylvestre

    2016-07-25

    The crystal structure and in vitro cytotoxicity of the amphiphilic ruthenium complex [3](PF6 )2 are reported. Complex [3](PF6 )2 contains a Ru-S bond that is stable in the dark in cell-growing medium, but is photosensitive. Upon blue-light irradiation, complex [3](PF6 )2 releases the cholesterol-thioether ligand 2 and an aqua ruthenium complex [1](PF6 )2 . Although ligand 2 and complex [1](PF6 )2 are by themselves not cytotoxic, complex [3](PF6 )2 was unexpectedly found to be as cytotoxic as cisplatin in the dark, that is, with micromolar effective concentrations (EC50 ), against six human cancer cell lines (A375, A431, A549, MCF-7, MDA-MB-231, and U87MG). Blue-light irradiation (λ=450 nm, 6.3 J cm(-2) ) had little influence on the cytotoxicity of [3](PF6 )2 after 6 h of incubation time, but it increased the cytotoxicity of the complex by a factor 2 after longer (24 h) incubation. Exploring the unexpected biological activity of [3](PF6 )2 in the dark elucidated an as-yet unknown bifaceted mode of action that depended on concentration, and thus, on the aggregation state of the compound. At low concentration, it acts as a monomer, inserts into the membrane, and can deliver [1](2+) inside the cell upon blue-light activation. At higher concentrations (>3-5 μm), complex [3](PF6 )2 forms supramolecular aggregates that induce non-apoptotic cell death by permeabilizing cell membranes and extracting lipids and membrane proteins. PMID:27373895

  19. Thermal stability of alkyl carbonate mixed-solvent electrolytes for lithium ion cells

    Science.gov (United States)

    Kawamura, Tetsuya; Kimura, Arihisa; Egashira, Minato; Okada, Shigeto; Yamaki, Jun-Ichi

    The thermal stability of some mixed-solvent electrolytes used in lithium cells was measured by differential scanning calorimetry (DSC) using airtight containers. The electrolytes used were ethylene carbonate ( EC)+ diethyl carbonate ( DEC) , EC+ dimethyl carbonate ( DMC) , propylene carbonate (PC)+DEC, and PC+DMC in which was dissolved 1 M LiPF 6 or 1 M LiClO 4. The influence of water addition and lithium metal addition on the thermal behavior of these electrolytes was also investigated. The exothermic peak of LiPF 6 electrolytes containing DEC was found at 255 °C, and the peak temperature of the electrolytes containing DEC was 15-20 °C lower than that of LiPF 6 electrolytes containing DMC. This effect was also observed in the electrolytes including LiClO 4. DMC was found to be more reactive than DEC. The thermal behavior of various kinds of LiPF 6 electrolytes with lithium metal was measured by DSC. The exothermic reaction of 1 M LiPF 6/EC+DEC, 1 M LiPF 6/EC+DMC, and 1 M LiPF 6/PC+DMC with lithium metal began at the melting point of lithium metal because of the break down of the solid electrolyte interface (SEI). The temperature was approximately 180 °C, whereas the self-heating of 1 M LiPF 6/PC+DEC occurred before the melting point of lithium metal. The temperature at which the self-exothermal reaction began was 140 °C. Therefore, the lithium metal in this electrolyte was found to be thermally unstable. When water was added to the above electrolytes with lithium metal, the exothermic reaction began at less than 130 °C, probably due to a collapse of SEI in response to the HF that was a product of the reaction between LiPF 6 and the added water.

  20. Synthesis and spectroscopic studies of silver and rhodium mono- and polynuclear complexes with multidentate phosphines (Ph2P)2CHR (R = H, Me, PPh2)

    NARCIS (Netherlands)

    Koten, G. van; Ploeg, A.F.M.J. van der

    1981-01-01

    Trinuclear [{(Ph{2}P){3}CH}Ag{3}(O{2}CR'){3}], dinuclear [{(Ph{2}P){2}CHR}Ag{2}(O{2}CR'){2}], [{(Ph{2}P){2}CHR}{2}Ag{2}](BF{4}){2} and (Rh{2}(Cl)(CO){2}{(Ph{2}P){2}CHMe}{2}][RhCl{2}(CO){2}], and mononuclear (Rh{(Ph{2}P){2}CHR}{2}](BF{4}), (Rh{(Ph{2}P){2}CHR}{2}HCl](BF{4}), d [Rh{(Ph{2}P){2}CHR}{2}Cl

  1. 一种新型固体聚合物电解质复合气体分离膜的制备及气体透过性能的研究%Preparation of new solid polymer electrolyte composite membrane and separation of propylene and propane

    Institute of Scientific and Technical Information of China (English)

    王雁北; 任吉中; 邓麦村

    2011-01-01

    采用单侧溶液交换法,把PEI/Pebax2533复合膜的Pebax2533外表面与AgBF4交换溶液接触,利用Ag+与Pebax2533分子链段中醚氧键之间的络合作用,将Ag+固定在PEI/Pebax2533复合膜中,从而制备了PEI/Pebax2533/AgBF4固体聚合物电解质复合气体分离膜.通过改变AgBF4交换溶液的浓度来调节复合膜表面银离子的负载量,控制复合膜对丙烯/丙烷的分离性能.随着AgBF4交换溶液浓度的增加,复合膜对烯烃出现明显的促进传递现象,塑性效应明显减弱.当AgBF4交换溶液浓度为8.0 mol/L时,PEI/Pebax2533/AgBF4复合膜丙烯/丙烷的分离系数远远超过1 000,塑性效应基本受到抑制.%A new solid polymer electrolyte PEI/Pebax2533/AgBF4 composite membrane is prepared with complexing method.By immersing the external surface of Pebax2533 layer of PEI/Pebax2533 composite membrane into AgBF4 solution, silver salt will transfer into Pebax2533 layer according to complexation with ether oxygen in Pebax2533 backbone, and a solid polymer electrolyte layer is formed.The silver salt content in the solid polymer electrolyte layer is dominated hy the AgBF4 concentration.The increase of AgBF4 concentration enhances carrier facilitated transport of propylene, and lowers its plasticization effect.For PEI/Pebax2533/AgBF4 composite membrane prepared with 8.0mol/L AgBF4 solution, its selectivity for propylene and propane is above 1000, and the plasticization effect is suppressed completely.

  2. CALCULATION OF CONDUCTANCE FOR ORGANIC SOLUTIONS OF LITHIUM SALT USING MEAN SPHERICAL APPROXIMATION THEORY%应用平均球近似理论计算锂盐有机溶液电导率

    Institute of Scientific and Technical Information of China (English)

    韩景立

    2004-01-01

    The molar conductance of electrolytes LiPF6-PC (propylene carbonate), LiPF6·2DG (diglyme)-PC and LiPF6·PMDETA (pentamethy[diethylenetriamine)-PC were calculated by using mean spherical approximation(MSA). The range of concentration was from 0.001 mol·L-1 to 1 mol·L-1. The dissociation equilibrium of salts is taken into account. The mean relative deviations were 5.6%, 4.2% and 4.7%,respectively.

  3. A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway.

    Science.gov (United States)

    Liu, Jinyong; Han, Mengwei; Wu, Dimao; Chen, Xi; Choe, Jong Kwon; Werth, Charles J; Strathmann, Timothy J

    2016-06-01

    Rapid reduction of aqueous ClO4(-) to Cl(-) by H2 has been realized by a heterogeneous Re(hoz)2-Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx(-) intermediates formed during reactions with concentrated ClO4(-) promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4(-) reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2(-) intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4(-) reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx(-) scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significantly mitigate Re complex decomposition by slightly lowering the OAT activity when immobilized in Pd/C. Further stability enhancement is then obtained by switching the nanoparticles from Pd to Rh, which exhibits high reactivity with ClOx(-) intermediates and thus prevents their deactivating reaction with the Re complex. Compared to Re(hoz)2-Pd/C, the new Re(hoz)(htz)-Rh/C catalyst exhibits similar ClO4(-) reduction activity but superior stability, evidenced by a decrease of Re leaching from 37% to 0.25% and stability of surface Re speciation following the treatment of a concentrated "challenge" solution containing 1000 ppm of ClO4(-). This work demonstrates the pivotal roles of coordination chemistry control and tuning of individual catalyst components for achieving both high activity and stability in environmental catalyst applications. PMID:27182602

  4. A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway.

    Science.gov (United States)

    Liu, Jinyong; Han, Mengwei; Wu, Dimao; Chen, Xi; Choe, Jong Kwon; Werth, Charles J; Strathmann, Timothy J

    2016-06-01

    Rapid reduction of aqueous ClO4(-) to Cl(-) by H2 has been realized by a heterogeneous Re(hoz)2-Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx(-) intermediates formed during reactions with concentrated ClO4(-) promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4(-) reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2(-) intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4(-) reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx(-) scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significantly mitigate Re complex decomposition by slightly lowering the OAT activity when immobilized in Pd/C. Further stability enhancement is then obtained by switching the nanoparticles from Pd to Rh, which exhibits high reactivity with ClOx(-) intermediates and thus prevents their deactivating reaction with the Re complex. Compared to Re(hoz)2-Pd/C, the new Re(hoz)(htz)-Rh/C catalyst exhibits similar ClO4(-) reduction activity but superior stability, evidenced by a decrease of Re leaching from 37% to 0.25% and stability of surface Re speciation following the treatment of a concentrated "challenge" solution containing 1000 ppm of ClO4(-). This work demonstrates the pivotal roles of coordination chemistry control and tuning of individual catalyst components for achieving both high activity and stability in environmental catalyst applications.

  5. Trinuclear manganese complexes of unsymmetrical polypodal diamino N3O3 ligands with an unusual [Mn3(μ-OR)4]5+ triangular core: synthesis, characterization, and catalase activity.

    Science.gov (United States)

    Ledesma, Gabriela N; Anxolabéhère-Mallart, Elodie; Rivière, Eric; Mallet-Ladeira, Sonia; Hureau, Christelle; Signorella, Sandra R

    2014-03-01

    Two new tri-Mn(III) complexes of general formula [Mn3L2(μ-OH)(OAc)]ClO4 (H3L = 1-[N-(2-pyridylmethyl),N-(2-hydroxybenzyl)amino]-3-[N'-(2-hydroxybenzyl),N'-(4-X-benzyl)amino]propan-2-ol; 1ClO4, X = Me; 2ClO4, X = H) have been prepared and characterized. X-ray diffraction analysis of 1ClO4 reveals that the complex cation possesses a Mn3(μ-alkoxo)2(μ-hydroxo)(μ-phenoxo)(4+) core, with the three Mn atoms bound to two fully deprotonated N3O3 chelating L(3-), one exogenous acetato ligand, and one hydroxo bridge, the structure of which is retained upon dissolution in acetonitrile or methanol. The three Mn atoms occupy the vertices of a nearly isosceles triangle (Mn1···Mn3 = 3.6374(12) Å, Mn2···Mn3 3.5583(13) Å, and Mn1···Mn2 3.2400(12) Å), with one substitution-labile site on the apical Mn ion occupied by terminally bound monodentate acetate. Temperature-dependent magnetic susceptibility studies indicate the presence of predominant antiferromagnetic intramolecular interactions between Mn(III) ions in 1ClO4. Complexes 1ClO4 and 2ClO4 decompose H2O2 at comparable rates upon initial binding of peroxide through acetate substitution, with retention of core structure during catalysis. Kinetic and spectroscopic studies suggest that these complexes employ the [Mn-(μ-oxo/aquo)-Mn](4+) moiety to activate peroxide, with the additional (μ-alkoxo)(μ-phenoxo)Mn(μ-alkoxo) metallobridge carrying out a structural function.

  6. Application of a Re-Pd bimetallic catalyst for treatment of perchlorate in waste ion-exchange regenerant brine.

    Science.gov (United States)

    Liu, Jinyong; Choe, Jong Kwon; Sasnow, Zachary; Werth, Charles J; Strathmann, Timothy J

    2013-01-01

    Concentrated sodium chloride (NaCl) brines are often used to regenerate ion-exchange (IX) resins applied to treat drinking water sources contaminated with perchlorate (ClO(4)(-)), generating large volumes of contaminated waste brine. Chemical and biological processes for ClO(4)(-) reduction are often inhibited severely by high salt levels, making it difficult to recycle waste brines. Recent work demonstrated that novel rhenium-palladium bimetallic catalysts on activated carbon support (Re-Pd/C) can efficiently reduce ClO(4)(-) to chloride (Cl(-)) under acidic conditions, and here the applicability of the process for treating waste IX brines was examined. Experiments conducted in synthetic NaCl-only brine (6-12 wt%) showed higher Re-Pd/C catalyst activity than in comparable freshwater solutions, but the rate constant for ClO(4)(-) reduction measured in a real IX waste brine was found to be 65 times lower than in the synthetic NaCl brine. Through a series of experiments, co-contamination of the IX waste brine by excess NO(3)(-) (which the catalyst reduces principally to NH(4)(+)) was found to be the primary cause for deactivation of the Re-Pd/C catalyst, most likely by altering the immobilized Re component. Pre-treatment of NO(3)(-) using a different bimetallic catalyst (In-Pd/Al(2)O(3)) improved selectivity for N(2) over NH(4)(+) and enabled facile ClO(4)(-) reduction by the Re-Pd/C catalyst. Thus, sequential catalytic treatment may be a promising strategy for enabling reuse of waste IX brine containing NO(3)(-) and ClO(4)(-).

  7. Lanthanide perchlorate complexes of quinoline-1-oxide and isoquinoline-2-oxide

    OpenAIRE

    Kalyanasundaram, R; Navaneetham, NS; Soundararajan, S.

    1985-01-01

    Complexes of lanthanide perchlorates with quinoline-1-oxide and isoquinoline-2-oxide have been isolated for the first time characterised by analysis, conductance and IR, NMR and electronic spectoral studies. The complexes of quinoline-1-oxide have the composition $Ln(QNO)_8$$(ClO_4)_3$ where Ln = La, Pr or Nd and $Ln(QNO)_7$ where Ln = Gd, Dy, Ho, Er, Yb. The isoquinoline-2-oxide complexes analyse for the formula $Ln(IsoQNO)_7(ClO_4)_3$ where Ln = La-Yb.

  8. Characterization of the Initial Intermediate Formed during Photoinduced Oxygenation of the Ruthenium(II) Bis(bipyridyl)flavonolate Complex.

    Science.gov (United States)

    Han, Xiaozhen; Klausmeyer, Kevin K; Farmer, Patrick J

    2016-08-01

    A ruthenium(II) flavonolate complex, [Ru(II)(bpy)2fla][BF4], was synthesized to model the reactivity of the flavonol dioxygenases. The treatment of dry CH3CN solutions of [Ru(II)(bpy)2fla][BF4] with dioxygen under light leads to the oxidative O-heterocyclic ring opening of the coordinated substrate flavonolate, resulting in the formation of [Ru(II)(bpy)2(carboxylate)][BF4] (carboxylate = O-benzoylsalicylate or benzoate) species, as determined by electrospray ionization mass spectrometry. Moderation of the excitation and temperature allowed isolation and characterization of an intermediate, [Ru(II)(bpy)2bpg][BF4] (bpg = 2-benzoyloxyphenylglyoxylate), generated by the 1,2-addition of dioxygen to the central flavonolate ring. PMID:27437831

  9. Nano-electromanipulation of Spin Crossover Nanorods: Towards Switchable Nanoelectronic Devices

    OpenAIRE

    Rotaru, Aurelian; Dugay, Julien; Tan, Reasmey P.; Gural'skiy, Il'ya A.; Salmon, Lionel; Demont, Philippe; Carrey, Julian; Molnar, Gabor; Respaud, Marc; Bousseksou, Azzedine

    2013-01-01

    The nanoscale manipulation and charge transport properties of the [Fe(Htrz)2(trz)](BF4) spin-crossover compound is demonstrated. Such 1D spin-crossover nanostructures are attractive building blocks for nanoelectronic switching and memory devices.

  10. Effect of 1-butyl-3-methylimidazolium tetrafluoroborate on the formation rate of CO2 hydrate

    Institute of Scientific and Technical Information of China (English)

    Qi Chen; Yong Yu; Peng Zeng; Wei Yang; Qianqing Liang; Xiaoming Peng; Yansheng Liu; Yufeng Hu

    2008-01-01

    The effect of the addition of 1-butyl-3-methylimidazolium tetrafluoroborate([C4mim][BF4])on the formation rates of CO2 hydrates was investigate.The isothermal and isobaric methods were used to measure the formation rates of CO2 hydrates.As compared to those of pure water,the data of phase equilibrium changed greatly.The effects of pressure,temperature,and the concentration of [C4mim][BF4] aqueous solution on the formation rates of CO2 hydrates were investigated.With a constant concentration of[C4mim][BF4],the rate of gas consumption was enhanced with the lowering of experimental temperature.However,a decrease in pressure exerted an opposite effect on the rate of gas consumption.Moreover,the addition of[C4mim][BF4]raised the equilibrium pressure of hydrate formation at the same temperature.

  11. Ambient Ionic Liquids Used in the Reduction ofAldehydes and Ketones

    Institute of Scientific and Technical Information of China (English)

    Dan Qian XU; Shu Ping LUO; Bao You LIU; Zhen Yuan XU; Yin Chu SHEN

    2004-01-01

    The sodium borohydride reduction of aldehydes and ketones to corresponding alcohols has been accomplished via the use of ionic liquids. The alcohols are easily obtained with excellent yields and the ionic liquid BMImBF4 could be reused.

  12. Microregion detection of ionic liquid microemulsions.

    Science.gov (United States)

    Gao, Yanan; Wang, Suqing; Zheng, Liqiang; Han, Shuaibing; Zhang, Xuan; Lu, Deming; Yu, Li; Ji, Yongqiang; Zhang, Gaoyong

    2006-09-15

    Nonaqueous ionic liquid (IL) microemulsion consisting of IL, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), surfactant TX-100, and toluene was prepared and the phase behavior of the ternary system was investigated. Electrical conductivity measurement was used for investigating the microregions of the nonaqueous IL microemulsions. On the basis of the percolation theory, the bmimBF(4)-in-toluene (IL/O), bicontinuous, and toluene-in-bmimBF(4) (O/IL) microregions of the microemulsions were successfully identified using insulative toluene as the titration phase. However, this method was invalid when conductive bmimBF(4) acted as the titration phase. The microregions obtained by conductivity measurements were further proved by electrochemical cyclic voltammetry experiments. The results indicated that the conductivity method was feasible for identifying microstructures of the nonaqueous IL microemulsions. PMID:16765365

  13. Volumetric properties, viscosities and refractive indices of binary liquid mixtures of tetrafluoroborate-based ionic liquids with methanol at several temperatures

    International Nuclear Information System (INIS)

    Highlights: • Mixtures of [bmim][BF4] or [emim][BF4] with methanol were studied. • Density, speed of sound, viscosity and refractive index were determined. • Excess volumes, isentropic compressibilities, properties deviations were calculated. • Properties excess and deviations were correlated with temperature and composition. - Abstract: Densities, speeds of sound, viscosities and refractive indices of two binary systems 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] + methanol and 1-ethyl-3-methylimidazolium tetrafluoroborate [emim][BF4] + methanol, as well as of all pure components, have been measured covering the whole range of compositions at T = (278.15 to 318.15) K and p = 101 kPa. From this data, excess molar volumes, excess isentropic compressibilities, viscosity deviations and refractive index deviations were calculated and fitted to extended versions of the Redlich–Kister equation. Estimated coefficients of these equations taking into account the dependence on composition and temperature simultaneously were also presented

  14. Chemistry of dihydrogen complexes containing only phosphorus co-ligands

    Indian Academy of Sciences (India)

    Balaji R Jagirdar; Nisha Mathew

    2002-08-01

    A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)2Ru(2-H2)(L)][BF4]2 (dppm = Ph2PCH2PPh2; L = phosphite) have been prepared by protonating the precursor hydride complexes cis-[(dppm)2Ru(H)(L)][BF4] using HBF4$\\cdot$Et2O. The precursor hydride complexes have been obtained from trans-[(dppm)2Ru(H)(L)][BF4] (L = phosphite) via a rare acidcatalysed isomerization reaction in six coordinate species. The trans-[(dppm)2Ru(H)(L)][BF4] complexes (L = phosphine) upon protonation gave the isomerized derivatives, however, further addition of acid resulted in a five-coordinate species, [(dppm)2RuCl]+ presumably via an intermediate phosphine dihydrogen complex. The electronic as well as the steric properties of the co-ligands seem to strongly influence the structure-reactivity behaviour of this series of complexes.

  15. One-Way Diffusion of Ionic Liquids in a Mixing Process with Water

    Science.gov (United States)

    Oikawa, Noriko; Tahara, Daiki; Kurita, Rei

    2016-09-01

    In contrast to the usual diffusive mixing process between two miscible liquids, the ionic liquid [Cnmim][PF6] forms a droplet in water while mixing. The droplet retains a sharp interface with surface tension, gradually decreasing in size until completely mixed with water. This peculiar behavior in the mixing process accompanies one-way diffusion, in which ions diffuse in one direction only from the bulk IL droplet into the bulk continuum of water. The activation energy of the one-way diffusion at the [Cnmim][PF6]/water interface increases with increasing length of the hydrophobic alkyl chains attached to the cation molecules of [Cnmim][PF6]. It is considered that the hydrophobic nanoscale structure observed in [C4mim][PF6] plays an important role in the generation of the droplet and the mixing dynamics.

  16. A 2D [Fe-II-bistetrazole] coordination polymer exhibiting spin-crossover properties

    NARCIS (Netherlands)

    Quesada, Manuel; Prins, Ferry; Roubeau, Olivier; Gamez, Patrick; Teat, Simon J.; van Koningsbruggen, Petra J.; Haasnoot, Jaap G.; Reedijk, Jan

    2007-01-01

    The reaction of 1,3-bis(tetrazol-1-yl)-2-propanol (btzpol) with Fe(BF4)(2) center dot 6H(2)O in acetonitrile yields the remarkable 2D coordination polymer [Fe-II(btzpol)(1.8)(btzpol-OBF3)(1.2)](BF4)(0.8) center dot (H2O)(0.8)(CH3CN) (1). This compound has been structurally characterized using an X-r

  17. Mechanism of dissolution of a lithium salt in an electrolytic solvent in a lithium ion secondary battery: a direct ab initio molecular dynamics (AIMD) study.

    Science.gov (United States)

    Tachikawa, Hiroto

    2014-06-01

    The mechanism of dissolution of the Li(+) ion in an electrolytic solvent is investigated by the direct ab initio molecular dynamics (AIMD) method. Lithium fluoroborate (Li(+)BF4(-)) and ethylene carbonate (EC) are examined as the origin of the Li(+) ion and the solvent molecule, respectively. This salt is widely utilized as the electrolyte in the lithium ion secondary battery. The binding of EC to the Li(+) moiety of the Li(+)BF4(-) salt is exothermic, and the binding energies at the CAM-B3LYP/6-311++G(d,p) level for n=1, 2, 3, and 4, where n is the number of EC molecules binding to the Li(+) ion, (EC)n(Li(+)BF4(-)), are calculated to be 91.5, 89.8, 87.2, and 84.0 kcal mol(-1) (per EC molecule), respectively. The intermolecular distances between Li(+) and the F atom of BF4(-) are elongated: 1.773 Å (n=0), 1.820 Å (n=1), 1.974 Å (n=2), 1.942 Å (n=3), and 4.156 Å (n=4). The atomic bond populations between Li(+) and the F atom for n=0, 1, 2, 3, and 4 are 0.202, 0.186, 0.150, 0.038, and 0.0, respectively. These results indicate that the interaction of Li(+) with BF4(-) becomes weaker as the number of EC molecules is increased. The direct AIMD calculation for n=4 shows that EC reacts spontaneously with (EC)3(Li(+)BF4(-)) and the Li(+) ion is stripped from the salt. The following substitution reaction takes place: EC+(EC)3(Li(+)BF4(-))→(EC)4Li(+)-(BF4(-)). The reaction mechanism is discussed on the basis of the theoretical results. PMID:24616076

  18. Trapping atmospheric CO2 with gold.

    Science.gov (United States)

    Collado, Alba; Gómez-Suárez, Adrián; Webb, Paul B; Kruger, Hedi; Bühl, Michael; Cordes, David B; Slawin, Alexandra M Z; Nolan, Steven P

    2014-10-01

    The ability of gold-hydroxides to fix CO2 is reported. [Au(IPr)(OH)] and [{Au(IPr)}2(μ-OH)][BF4] react with atmospheric CO2 to form the trigold carbonate complex [{Au(IPr)}3(μ(3)-CO3)][BF4]. Reactivity studies revealed that this complex behaves as two basic and one cationic Au centres, and that it is catalytically active. DFT calculations and kinetic experiments have been carried out.

  19. Water Phase Diagram Is Significantly Altered by Imidazolium Ionic Liquid

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    We report unusually large changes in the boiling temperature, saturated vapor pressure, and structure of the liquid-vapor interface for a range of 1-butyl-3-methyl tetrafluoroborate, [C4C1IM][BF4]-water mixtures. Even modest molar fractions of [C4C1IM][BF4] significantly affect the phase behavior...... vapor pressures are discussed at the atomistic resolution. The reported results guide the search for novel scientific and technological applications of ion-molecular systems....

  20. IMPEDANCE CHARACTERISTICS OF POLYFURAN FILMS

    Institute of Scientific and Technical Information of China (English)

    Liang Li; Xiao-bo Wan; Gi Xue

    2002-01-01

    Electrochemical impedance spectroscopy (EIS) was first used for the characterization of polyfuran (PFu) films that had been formed electrochemically on an Au electrode. The polyfuran was measured in high oxidation state, intermediate oxidation state and reduction state, respectively. As the oxidation level is increased, the ionic conductivity of PFu/BF4-increases. And impedance studies on PFu show that the anion BF4- appears to be mobile with a high diffusion coefficient of approximately 10-8 cm2 @ s-1.

  1. Facile synthesis of thiourea derivatives in ionic liquid

    Institute of Scientific and Technical Information of China (English)

    Min Liang Xiao; Feng Huang Chen; Zhi Juan Chen; Bao Shou Guo; Xian Hai Lv; Wen Ming Tang

    2007-01-01

    The synthesis of cinnamoyl thiourea derivatives from cinnamoyl isothiocyanate (CIT) with substituted aniline (RC6H4NH2) was investigated in the mostly used ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4]. Significant enhancements in reactivity, yield and reaction rate were achieved. The products could be recovered by simple filtration. [Bmim][BF4] could be recycled simply by removing water under vacuum and reused at least 9 times without significant decrease in activity.

  2. Iminium Salts by Meerwein Alkylation of Ehrlich’s Aldehyde

    Directory of Open Access Journals (Sweden)

    Gerhard Laus

    2013-03-01

    Full Text Available 4-(Dimethylaminobenzaldehyde is alkylated at the N atom by dialkyl sulfates, MeI, or Me3O BF4. In contrast, ethylation by Et3O BF4 occurs selectively at the O atom yielding a quinoid iminium ion. 4-(Diethylaminobenzaldehyde is alkylated only at O by either Et or Me oxonium reagent. The iminium salts are prone to hydrolysis giving the corresponding hydrotetrafluoroborates. Five crystal structures were determined.

  3. Corrosion of steel in ionic liquids

    OpenAIRE

    Arenas M.F.; Reddy R.G.

    2003-01-01

    The corrosion behavior of 1018 carbon steel alloy has been investigated by electrochemical techniques. The ionic liquids studied were 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), 1 hexyl-3-methylimidazolium hexafluorophosphate ([C6mim]PF6) 1-octyl-3-methylimidazolium hexafluorophosphate ([C8mim]PF6), and 1-butyl-3-methylimidazolium bis-(trifluoromethanesulfonyl) imide ([C4mim][Tf2N]). Potentiodynamic polarization and Tafel plots were used to determine the corrosion behavior of the carbon...

  4. Bis[(diphenylphosphanylmethyldiphenylphosphane sulfide-κ2P,S]copper(I hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Jing-Jing Zhang

    2012-06-01

    Full Text Available In the title compound, [Cu(C25H22P2S2]PF6, the CuI atom, lying on a twofold rotation axis, adopts a distorted tetrahedral geometry. The (diphenylphosphanylmethyldiphenylphosphane sulfide ligand coordinates to the CuI atom through one S and one P atom, forming a stable five-membered chelate ring. The P atom of the PF6− anion also lies on a twofold rotation axis.

  5. New Host Molecules with Imidazoliums as Functional Arms:Syntheses and Anion Recognition

    Institute of Scientific and Technical Information of China (English)

    YUAN,Yi(袁艺); JIANG,Zong-Lin(蒋宗林); GAO,Ge(高戈); ZHANG,Guo-Lin(张国林); YOU,Jing-Song(游劲松); XIE,Ru-Gang(谢如刚)

    2002-01-01

    The bridged tri-imidazoliums 3@ 3X-—5@ 3X-(X- = PF-6,Br-,I-)and bis-imidazoliums 6@ 2PF-6 were synthesized by N-quaternization of imidazole derivative 1 in acetonitrile under reflux. UV spectroscopic titration experiments showed that the halide salts and hexafluorophosphate salts of these imidazoliums exhibited good recognition toward anions in water and in acetonitrile, respectively.

  6. An effective method for enhancing metal-ions' selectivity of ionic liquid-based extraction system: Adding water-soluble complexing agent.

    Science.gov (United States)

    Sun, Xiao Qi; Peng, Bo; Chen, Ji; Li, De Qian; Luo, Fang

    2008-01-15

    Selective extraction-separation of yttrium(III) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim][PF(6)]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [C(n)mim][PF(6)]/[Tf(2)N]-based extraction system without increasing the loss of [C(n)mim](+).

  7. Molecular sieve supported ionic liquids as efficient adsorbent for CO2 capture

    Directory of Open Access Journals (Sweden)

    Yang Na

    2015-01-01

    Full Text Available [NH3e-mim][BF4], [OHe-mim][BF4] and [HOEAm] were selected and supported onto molecular sieves NaY, USY, SAPO-34 and MCM-41, to prepare supported ionic liquids. It was found that [NH3e-mim][BF4]/NaY has excellent CO2 adsorption performance, with adsorption capacity of 0.108 mmolCO2/g. This paper investigates the optimal adsorption conditions and recyclability of [NH3e-mim][BF4]/NaY. The results show that [NH3e-mim][BF4]/NaY has good CO2 adsorption under the condition of 20°C and 20% ILs loading amount. By vacuum heating, CO2 adsorption capacity reaches 0.451mmolCO2/g at fifth runs and reduces to 0.29mmolCO2/g at tenth runs. The structure and characterization of the [NH3e-mim][BF4]/NaY was examined by FT-IR, XRD, SEM and TG-DSC. TG-DSC also shows that it has good thermostability below 50°C.

  8. 1,3-二甲基咪唑四氟硼酸盐的合成及其水溶液的蒸气压测定%Vapor Pressure Measurement of Water+1,3-Dimethylimidazolium Tetrafluoroborate System

    Institute of Scientific and Technical Information of China (English)

    武向红; 李静; 范丽华; 郑丹; 董丽

    2011-01-01

    In absorption cycles, ionic liquid (IL) 1,3-dimethylimidazolium tetrafluoroborate ([Dmim]BF4) may be a promising absorbent of working pair using water as refrigerant. The vapor pressures of [Dmim]BF4 aqueous solution were measured with the boiling-point method in the temperature range from 312.25 to 403.60 K and in the mass concentration range of 65% to 90% of [Dmim]BF4. The experimental data were correlated with an Antoine-type equation and the Non-Random Two-Liquid (NRTL) model, and the average absolute deviations between the experimental and calculated values were 1.06% and 1.15%, respectively. For the [Dmim]BF4 aqueous solution, the experimental vapor pressures show negative deviations from the calculated data with Raoult's law. For higher mass concentration of the IL, the deviation is more negative. In addition, the vapor pressures, the hydrophilicity and the solubility of [Dmim]BF4 aqueous solutions were compared with those of [Dmim]C1 aqueous solutions and [Bmim]BF4 aqueous solutions at IL-mole fraction of 0.20.

  9. Nanodroplet cluster formation in ionic liquid microemulsions.

    Science.gov (United States)

    Gao, Yanan; Voigt, Andreas; Hilfert, Liane; Sundmacher, Kai

    2008-08-01

    A common ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), is used as polar solvent to induce the formation of a reverse bmimBF(4)-in-toluene IL microemulsion with the aid of the nonionic surfactant Triton X-100. The swelling process of the microemulsion droplets by increasing bmimBF(4) content is detected by dynamic light scattering (DLS), conductivity, UV/Vis spectroscopy, and freeze-fracture transmission electron microscopy (FF-TEM). The results show that the microemulsion droplets initially formed are enlarged by the addition of bmimBF(4). However, successive addition of bmimBF(4) lead to the appearance of large-sized microemulsion droplet clusters (200-400 nm). NMR spectroscopic analysis reveal that the special structures and properties of bmimBF(4) and Triton X-100 together with the polar nature of toluene contribute to the formation of such self-assemblies. These unique self-assembled structures of IL-based microemulsion droplet clusters may have some unusual and unique properties with a number of interesting possibilities for potential applications. PMID:18576451

  10. Selective formation of silver(i) bis-phospholane macrocycles and further evidence that gold(i) is smaller than silver(i).

    Science.gov (United States)

    Streitberger, Markus; Schmied, Andy; Hoy, Reinhard; Hey-Hawkins, Evamarie

    2016-08-01

    A new synthetic approach to highly flexible bis-phospholanes from 1-benzylphospholane (1) as starting material is described. Silver(i) macrocycles containing 16 ([Ag2(μ-3a)2](BF4)2, 4), 20 ([Ag2(μ-3b)2](BF4)2, 5), 24 ([Ag2(μ-3c)2](BF4)2, 6), and 28 ([Ag2(μ-3d)2](BF4)2, 7) atoms in the ring were obtained in one step from AgBF4 and the respective bis-phospholane (C4H8P)(CH2)n(PC4H8) (n = 5, 7, 9, 11; 3a-d) in excellent yields. Comparison of 6 with the previously reported isomorphous complex [Au2(μ-3c)2](BF4)2 gave further evidence that gold(i) is significantly smaller than silver(i). All complexes were fully characterized by NMR and IR spectroscopy, mass spectrometry, and X-ray diffraction. PMID:27221148

  11. Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire

    Science.gov (United States)

    Shen, Jun-Jian; Zhong, Yu-Wu

    2015-09-01

    The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A “hybridized redox-asymmetry” method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N•+) charge transfer transitions have been identified for the odd-electron compounds 12+-62+ by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of -0.137 Å-1. DFT calculations have been performed to complement these experimental results.

  12. Synthesis of cyano-bridged bimetallic complexes of 5-indenyl ruthenium(II): Characterization and spectroscopic studies

    Indian Academy of Sciences (India)

    K Mohan Rao; E K Rymmai

    2001-02-01

    Reactions of the cyanide complexes of the type [(Ind)Ru(PPh3)2CN] (1), [(Ind)Ru(dppe)CN] (2), [(Cp)Ru(PPh3)2CN] (3), with the corresponding chloro complexes [(Ind)Ru(PPh3)2Cl] (4), [(Ind)Ru(dppe)Cl] (5), [(Cp)Ru(PPh3)2Cl] (6), in the presence of NH4PF6 salt give homometallic cyano-bridged compounds of the type [(Ind)(PPh3)2Ru-CN-Ru(PPh3)2(Cp)]PF6 (7), [(Ind)(PPh3)2Ru-CN-Ru(PPh3)2(Ind)] PF6 where Ind = indenyl, 5-C9H7, (8), [(Cp)(PPh3)2Ru-CN-Ru(dppe)(Ind)]PF6, dppe = (Ph2PCH2CH2PPh2) (9), [(Ind(dppe)Ru-CN-Ru(PPh3)2(Ind)PF6 (10) and [(Ind)(dppe)Ru-CN-Ru(PPh3)2(Cp)]PF6 (11) respectively. Reaction of complex 3 with [(p-cymene)RuCl2]2 dimer gave a mixed dimeric complex [(Cp)Ru(PPh3)2-CN-RuCl2(-cymene)] (12). All these complexes have been characterized by IR, 1H, 13C and 31 P NMR spectroscopy and C, H, N analyses.

  13. Determination and Correlation of Solubilities of Four Novel Benzothiazolium Ionic Liquids with 6PF- in Six Alcohols

    Institute of Scientific and Technical Information of China (English)

    何志坚; 王小敏; 姚田; 宋航; 姚舜

    2014-01-01

    Four novel benzothiazolium ionic liquids with 6PF- ([C1Bth][PF6], [C4Bth][PF6], [C5Bth][PF6] and [C6Bth][PF6]) were synthesized, and the rang of their melting points were determined between 358.35 K-424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected‘S’ type ten-dency. Then, the solubilities of the four ionic liquids in six lower alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) were measured in the temperature rang of 253.15-383.15 K at at-mospheric pressure with static analytical method, respectively. It was found that [C6Bth][PF6] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C4Bth][PF6] in methanol was very sensi-tive for temperature in 313.15-333.15 K, which was so-called “temperature-sensitivity”. This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids (ILs) become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation andλh equation, respectively. It was found that the result of correlation using two divided tem-perature ranges was better than that of using the whole temperature range.

  14. 锂离子电池电解质锂盐的发展历程和新型锂盐的研究进展%Development of Lithium Ion Battery Electrolyte and Research Progress of Novel Lithium Salts

    Institute of Scientific and Technical Information of China (English)

    闫春生; 李媛媛; 刘园园

    2016-01-01

    LiPF6 has become the most widely used commercial lithium battery electrolyte with brilliant ion-ic conductivity,better oxidation stability and less environmental pollution etc. Because LiPF6 thermal sta-bility is poor,the price is relatively expensive,the development and preparation of new lithium salts be-come a focus of attention for researchers. In this paper,the development of traditional lithium electrolyte is reviewed,the synthesis process of LiPF6 is summarized ,and research progress of new lithium salts is in-troduced.%六氟磷酸锂( LiPF6)因其突出的离子电导率、较优的氧化稳定性和较小的环境污染等优点成为目前使用最广泛的商业化锂电池电解质。由于LiPF6热稳定性较差、价格相对昂贵,使得新型锂盐的开发与制备成为研究者们关注的热点。本文回顾了传统锂盐电解质的发展,对LiPF6的合成工艺进行了综述,并介绍了新型锂盐的研究进展情况。

  15. 高氯酸诺氟沙星铜(Ⅱ)%Norfloxacin Coppe(Ⅱ) Perchlorate

    Institute of Scientific and Technical Information of China (English)

    谢永荣; 叶琼; 熊仁根

    2004-01-01

    The hydrothermal treatment of Cu(ClO4)2·6H2O and Norfloxacin (H-Norf) afforded [Cu(H-Noff)2(ClO4)2] (1) in which center Cu has a square planar geometry while perchlorate just acts as charge balance anions. CCDC:140821.

  16. Influence of processes of structure formation in mixed solvent and anion nature on cadmium ions discharge kinetics from water-dimethylformamide electrolyte

    International Nuclear Information System (INIS)

    Electrochemical reaction of cadmium ion discharge in water-dimethylformamide (DMF) solutions is studied. The influence of DMF concentration in the presence of different anions (ClO4-, F-, I-) on both reaction kinetics and mechanism is discussed on the basis of structural transformations in the mixed solvent and near the surface electrode processes

  17. Self-assembly of a chiral carbonate- and cytidine-containing dodecanuclear copper(II) complex: a multiarm-supplied globular capsule.

    Science.gov (United States)

    Armentano, Donatella; Marino, Nadia; Mastropietro, Teresa F; Martínez-Lillo, José; Cano, Joan; Julve, Miguel; Lloret, Francesc; De Munno, Giovanni

    2008-11-17

    A dodecanuclear copper(II) globular-shaped structure has been obtained with the cytidine nucleoside and the templating carbonate anion. It shows receptor properties through anion-cation and multiple anion-pi interactions toward ClO 4 (-) as well as an overall antiferromagnetic coupling.

  18. Drug: D03675 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D03675 Drug Delmadinone acetate (USAN) C23H27ClO4 402.1598 402.9111 D03675.gif Prog...ts CAS: 13698-49-2 PubChem: 17397771 LigandBox: D03675 NIKKAJI: J8.444A ATOM 28 1 C1y C 34.5419 -20.1300 2 C

  19. Synthetic, structural, spectroscopic and theoretical study of a Mn(III)-Cu(II) dimer containing a Jahn-Teller compressed Mn ion

    DEFF Research Database (Denmark)

    Berg, Nelly; Hooper, Thomas N.; Liu, Junjie;

    2013-01-01

    The heterobimetallic complex [Cu(II)Mn(III)(L)(2)(py)(4)](ClO(4))·EtOH (1) built using the pro-ligand 2,2'-biphenol (LH(2)), contains a rare example of a Jahn-Teller compressed Mn(III) centre. Dc magnetic susceptibility measurements on 1 reveal a strong antiferromagnetic exchange between the Cu(I...

  20. Crystal structure of barium perchlorate anhydrate, Ba(ClO42, from laboratory X-ray powder data

    Directory of Open Access Journals (Sweden)

    Jeonghoo H. Lee

    2015-06-01

    Full Text Available The previously unknown crystal structure of barium perchlorate anhydrate, determined and refined from laboratory X-ray powder diffraction data, represents a new structure type. The title compound was obtained by heating hydrated barium perchlorate [Ba(ClO42·xH2O] at 423 K in vacuo for 6 h. It crystallizes in the orthorhombic space group Fddd. The asymmetric unit contains one Ba (site symmetry 222 on special position 8a, one Cl (site symmetry 2 on special position 16f and two O sites (on general positions 32h. The structure can be described as a three-dimensional polyhedral network resulting from the corner- and edge-sharing of BaO12 polyhedra and ClO4 tetrahedra. Each BaO12 polyhedron shares corners with eight ClO4 tetrahedra, and edges with two ClO4 tetrahedra. Each ClO4 tetrahedron shares corners with four BaO12 polyhedra, and an edge with the other BaO12 polyhedron.

  1. Mn(II) complexes with bipyridine, phenanthroline and benzoic acid: Biological and catalase-like activity

    Indian Academy of Sciences (India)

    Ibrahim Kani; Özlem Atlier; Kiymet Güven

    2016-04-01

    Five mononuclear Mn(II) complexes, [Mn(phen)2(ClO4)2] (1), [Mn(phen)3](ClO4)2(H2CO3)2(2), [Mn(bipy)2(ClO4)2] (3), [Mn(bipy)3](ClO4)2) (4), and Mn(phen)2(ba)(H2O)](ClO4)(CH3OH) (5), where bipy = 2,2’-bipyridine, phen = 1,10-phenanthroline, and ba = benzoic acid were prepared and characterized by Xray, IR and UV-Vis spectroscopies, and their catalase-like and biological activities were studied. The presence of two different types and the number of chelating NN-donor neutral ligands allowed for analysis of their effects on the catalase and biological activities. It was observed that the presence and number of phen ligands improved the activity more than the bipy ligand. Complexes 1 and 2, which contain more basic phen ligands, disproportionate H2O2 faster than complexes 3 and 4, which contain less basic bipy ligands. The in vitro antimicrobial activities of all the complexes were also tested against seven bacterial strains by microdilution tests. All the bacterial isolates demonstrated sensitivity to the complexes and the antifungal (anticandidal) activities of the Mn(II) complexes were remarkably higher than the reference drug ketoconazole.

  2. High ozone increases soil perchlorate but does not affect foliar perchlorate content

    Science.gov (United States)

    Ozone (O3) is implicated in the natural source inventory of perchlorate (ClO4-), a hydrophilic salt that migrates to ground water and interferes with uptake of iodide in mammals, including humans. Tropospheric O3 is elevated in many areas. We previously showed (Grantz et al., 2013; Environmental Pol...

  3. EFFECTS OF LOW DOSE MIXTURES OF PCB126 AND PERCHLORATE ON THE HYPTHALAMIC-PITUITARY-THYROID (HPT) AXIS IN THE MALE RAT.

    Science.gov (United States)

    Perchlorate (ClO4) and 3,3',4,4',5-pentachlorobiphenyl (PCB126) are environmental contaminants known to disturb thyroid hormone homeostasis by well defined modes of action that lead to hypothyroidism in the rat. PCB126 increases phase II conjugation of T4 (T4-glucuronide) by indu...

  4. Energy-level tailoring in a series of redox-rich quinonoid-bridged diruthenium complexes containing tris2-pyridylmethyl)amine as a co-ligand.

    Science.gov (United States)

    Weisser, Fritz; Huebner, Ralph; Schweinfurth, David; Sarkar, Biprajit

    2011-05-01

    Reactions of [{Ru(tmpa)}2(μ-Cl)2][ClO4]2, (2[ClO4]2, tmpa=tris(2-pyridylmethyl)amine) with 2,5-dihydroxy-1,4-benzoquinone (L1), 2,5-di-[2,6-(dimethyl)-anilino]-1,4-benzoquinone (L2), or 2,5-di-[2,4,6-(trimethyl)-anilino)]-1,4-benzoquinone (L3) in the presence of a base led to the formation of the dinuclear complexes [{Ru(tmpa)}2(μ-L1-2H)][ClO4]2 (3[ClO4]2), [{Ru(tmpa)}2(μ-L2-2H)][ClO4]2 (4[ClO4]2), and [{Ru(tmpa)}2(μ-L3-2H)][ClO4]2 (5[ClO4]2). Structural characterization of 5[ClO4]2 showed the localization of the double bonds within the quinonoid ring and a twisting of the mesityl substituents with respect to the quinonoid plane. Cyclic voltammetry of the complexes show two reversible oxidation and quinonoid-based reduction processes. Results obtained from UV/Vis/NIR and EPR spectroelectrochemistry are invoked to discuss ruthenium- versus quinonoid-ligand-centered redox activity. The complex 3[ClO4]2 is compared to the reported complex [{Ru(bpy)}2(μ-L1-2 H)]2+ (12+, bpy=2,2′-bipyridine). The effects of substituting the bidentate and better π-accepting bpy co-ligands with tetradentate tmpa ligands [pure σ-donating (amine) as well as σ-donating and π-accepting (pyridines)] on the redox and electronic properties of the complexes are discussed. Comparisons are also made between complexes containing the dianionic forms of the all-oxygen-donating L1 ligand with the L2 and L3 ligands containing an [O,N,O,N] donor set. The one-electron oxidized forms of the complexes show absorption in the NIR region. The position as well as the intensity of this band can be tuned by the substituents on the quinonoid bridge. In addition, this band can be switched on and off by using tunable redox potentials, making such systems attractive candidates for NIR electrochromism. PMID:21688408

  5. Electronic structure and catalytic aspects of [Ru(tpm)(bqdi)(Cl/H2O)]n, tpm = tris(1-pyrazolyl)methane and bqdi = o-benzoquinonediimine.

    Science.gov (United States)

    Agarwala, Hemlata; Ehret, Fabian; Chowdhury, Abhishek Dutta; Maji, Somnath; Mobin, Shaikh M; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2013-03-14

    The diamagnetic complexes [Ru(tpm)(bqdi)(Cl)]ClO(4) ([1]ClO(4)) (tpm = tris(1-pyrazolyl)methane, bqdi = o-benzoquinonediimine) and [Ru(tpm)(bqdi)(H(2)O)](ClO(4))(2) ([2](ClO(4))(2)) have been synthesized. The valence state-sensitive bond distances of coordinated bqdi [C-N: 1.311(5)/1.322(5) Å in [1]ClO(4); 1.316(7)/1.314(7) Å in molecule A and 1.315(6)/1.299(7) Å in molecule B of [2](ClO(4))(2)] imply its fully oxidised quinonediimine (bqdi(0)) character. DFT calculations of 1(+) confirm the {Ru(II)-bqdi(0)} versus the antiferromagnetically coupled {Ru(III)-bqdi˙(-)} alternative. The (1)H NMR spectra of [1]ClO(4) in different solvents show variations in chemical shift positions of the NH (bqdi) and CH (tpm) proton resonances due to their different degrees of acidity in different solvents. In CH(3)CN/0.1 mol dm(-3) Et(4)NClO(4), [1]ClO(4) undergoes one reversible Ru(II)⇌ Ru(III) oxidation and two reductions, the reversible first electron uptake being bqdi based (bqdi(0)/bqdi˙(-)). The electrogenerated paramagnetic species {Ru(III)-bqdi(0)}(1(2+)) and {Ru(II)-Q˙(-)}(1) exhibit Ru(III)-type (1(2+): = 2.211/Δg = 0.580) and radical-type (1: g = 1.988) EPR signals, respectively, as is confirmed by calculated spin densities (Ru: 0.767 in 1(2+), bqdi: 0.857 in 1). The aqua complex [2](ClO(4))(2) exhibits two one-electron oxidations at pH = 7, suggesting the formation of {Ru(IV)[double bond, length as m-dash]O} species. The electronic spectral features of 1(n) (n = charge associated with the different redox states of the chloro complex: 2+, 1+, 0) in CH(3)CN and of 2(2+) in H(2)O have been interpreted based on the TD-DFT calculations. The application potential of the aqua complex 2(2+) as a pre-catalyst towards the epoxidation of olefins has been explored in the presence of the sacrificial oxidant PhI(OAc)(2) in CH(2)Cl(2) at 298 K, showing the desired selectivity with a wide variety of alkenes. DFT calculations based on styrene as the model substrate predict that the epoxidation reaction proceeds through a concerted transition state pathway.

  6. Molecular simulation and experimental study of CO2 absorption in ionic liquid reverse micelle.

    Science.gov (United States)

    Shi, Wei; Hong, Lei; Damodaran, Krishnan; Nulwala, Hunaid B; Luebke, David R

    2014-12-01

    The structure and dynamics for CO2 absorption in ionic liquid reverse micelle (ILRM) were studied using molecular simulations. The ILRM consisted of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) ionic liquid (IL) as the micelle core, the benzylhexadecyldimethylammonium ([BHD](+)) chloride ([Cl](-)) was the cationic surfactant, and benzene was used as the continuous solvent phase in this study. The diffusivity values of this ILRM system were also experimentally determined. Simulations indicate that there is ion exchange between the IL anion ([BF4](-)) and the surfactant anion ([Cl](-)). It was also found that the [bmim][BF4] IL exhibits small local density at the interface region between the IL core and the [BHD](+) surfactant cation layer, which leads to a smaller density for the [bmim][BF4] IL inside the reverse micelle (RM) compared with the neat IL. These simulation findings are consistent with experimental results. Both our simulations and experimental results show that [bmim][BF4] inside the RM diffuses 5-26 times faster than the neat IL, which is partly due to the fast particle diffusion for the ILRM nanodroplet (IL and surfactant) as a whole in benzene solvent compared with neat [bmim][BF4] diffusion. Additionally, it was found that [bmim][BF4] IL solved in benzene diffuses 2 orders of magnitude faster than the neat IL. Lastly, simulations show that CO2 molecules are absorbed in four different regions of the ILRM system, that is, (I) in the IL inner core, (II) in the [BHD](+) surfactant cation layer, (III) at the interface between the [BHD](+) surfactant cation layer and benzene solvent, and (IV) in the benzene solvent. The CO2 solubility was found to decrease in the order II > III ∼ IV > I, while the CO2 diffusivity and permeability decrease in the following order: IV > III > II > I. PMID:25382316

  7. A new technology for separation and recovery of materials from waste printed circuit boards by dissolving bromine epoxy resins using ionic liquid

    International Nuclear Information System (INIS)

    Highlights: ► WPCBs were heated in [EMIM+][BF4−] for recovering solider at 240 °C. ► The bromine epoxy resins in WPCBs were all dissolved in [EMIM+][BF4−] at 260 °C. ► Used [EMIM+][BF4−] is treated by water to obtain regeneration. - Abstract: Recovery of valuable materials from waste printed circuit boards (WPCBs) is quite difficult because WPCBs is a heterogeneous mixture of polymer materials, glass fibers, and metals. In this study, WPCBs was treated using ionic liquid (1-ethyl-3-methylimizadolium tetrafluoroborate [EMIM+][BF4−]). Experimental results showed that the separation of the solders went to completion, and electronic components (ECs) were removed in WPCBs when [EMIM+][BF4−] solution containing WPCBs was heated to 240 °C. Meanwhile, metallographic observations verified that the WPCBs had an initial delamination. When the temperature increased to 260 °C, the separation of the WPCBs went to completion, and coppers and glass fibers were obtained. The used [EMIM+][BF4−] was treated by water to generate a solid–liquid suspension, which was separated completely to obtain solid residues by filtration. Thermal analyses combined with infrared ray spectra (IR) observed that the solid residues were bromine epoxy resins. NMR (nuclear magnetic resonance) showed that hydrogen bond played an important role for [EMIM+][BF4−] dissolving bromine epoxy resins. This clean and non-polluting technology offers a new way to recycle valuable materials from WPCBs and prevent environmental pollution from WPCBs effectively.

  8. Synthesis, electrochemical and photophysical properties of heterodinuclear Ru-Mn and Ru-Zn complexes bearing ambident Schiff base ligand.

    Science.gov (United States)

    Guillo, Pascal; Hamelin, Olivier; Loiseau, Frédérique; Pécaut, Jacques; Ménage, Stéphane

    2010-06-28

    While ruthenium tris(diimine) complexes have been extensively studied, this is not the case with ruthenium bis(diimine)X(2) complexes where X represents a pyridinyl-based ligand. The synthesis of a new complex ([2][PF(6)](2)) bearing two ambident Schiff base ligands (HL) constituted by the assembly of phenol and pyridinyl moieties is reported. Thanks to the heteroditopic property of HL, compound [2](2+) was used as an original metalloligand for the coordination of a redox-active (Mn(III)) and redox-inactive (Zn(II)) second metal cation affording three heterodinuclear complexes, namely, [(bpy)(2)Ru(2)Mn(acac)][PF(6)](2) ([3][PF(6)](2); acac = acetylacetonate), [(bpy)(2)Ru(2)Mn(OAc)][PF(6)](2) ([4][PF(6)](2), OAc = acetate), and [(bpy)(2)Ru(2)Zn][PF(6)](2) ([5][PF(6)](2)). The influence of the second metal with regard to the photophysical and electrochemical properties of the ruthenium bis(diimine)X(2) subunit was then investigated. In the case of Ru(II)-Mn(III) heterodinuclear complexes, a partial quenching of the luminescence was observed as a consequence of an efficient electron transfer process from the ruthenium to the manganese. EPR and spectrophotometric analyses of the oxidized species resulting from the one-electron oxidation of compounds [3](2+) and [4](2+) showed the formation of a Mn(IV) species for [3](2+) and an organic free radical for [4](2+). PMID:20485756

  9. Improvement on the storage performance of LiMn2O4 with the mixed additives of ethanolamine and heptamethyldisilazane

    Science.gov (United States)

    Wu, Xianwen; Li, Xinhai; Wang, Zhixing; Guo, Huajun; Yue, Peng; Zhang, Yunhe

    2013-03-01

    The commercial LiMn2O4 are added into the LiPF6-based electrolyte without or with the mixed additives of ethanolamine and heptamethyldisilazane to be exposed in air at 60 °C for 2-6 h, and the effect of different electrolytes on the storage behavior of LiMn2O4 materials and LiMn2O4/Li cells at elevated temperature is investigated comparatively for the first time by FTIR, SEM, TEM, XRD and charge-discharge measurements. The results show that the electrochemical performances of LiMn2O4 exposed in the LiPF6-based electrolyte become worse gradually with the storage time increasing. However, when the mixture of ethanolamine and heptamethyldisilazane as electrolyte additives is added into the LiPF6-based electrolyte, it can stabilize the original morphology and spinel structure of LiMn2O4 greatly and improve the storage performance of the material and LiMn2O4/Li cells effectively. As the commercial LiMn2O4 is exposed in the LiPF6-based electrolyte with additives for 4 h at 60 °C, the initial discharge capacity of 97.7 mA h g-1 at 0.1 C and the capacity retention of 89.14% at 1 C rate after 150 cycles are much better than that LiMn2O4 exposed in the LiPF6-based electrolyte under the same conditions. Furthermore, the LiMn2O4/Li cells using the LiPF6-based electrolyte with additives exhibit higher initial discharge capacity before storage and higher capacity retention after storage at 60 °C for a week compared to the cells without additives in the LiPF6-based electrolyte.

  10. Cytotoxicity of Ru(II) piano-stool complexes with chloroquine and chelating ligands against breast and lung tumor cells: Interactions with DNA and BSA.

    Science.gov (United States)

    Colina-Vegas, Legna; Villarreal, Wilmer; Navarro, Maribel; de Oliveira, Clayton Rodrigues; Graminha, Angélica E; Maia, Pedro Ivo da S; Deflon, Victor M; Ferreira, Antonio G; Cominetti, Marcia Regina; Batista, Alzir A

    2015-12-01

    The synthesis and spectroscopic characterization of nine π-arene piano-stool ruthenium (II) complexes with aromatic dinitrogen chelating ligands or containing chloroquine (CQ), are described in this study: [Ru(η(6)-C10H14)(phen)Cl]PF6 (1), [Ru(η(6)-C10H14)(dphphen)Cl]PF6 (2), [Ru(η(6)-C10H14)(bipy)Cl]PF6 (3), [Ru(η(6)-C10H14)(dmebipy)Cl]PF6 (4) and [Ru(η(6)-C10H14)(bdutbipy)Cl]PF6 (5), [Ru(η(6)-C10H14)(phen)CQ](PF6)2 (6), [Ru(η(6)-C10H14)(dphphen)CQ](PF6)2 (7), [Ru(η(6)-C10H14)(bipy)CQ](PF6)2 (8), [Ru(η(6)-C10H14)(dmebipy)CQ](PF6)2 (9): [1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dphphen), 2,2'-bipyridine (bipy), 5,5'-dimethyl-2,2'-bipyridine (dmebipy), and 4,4'-di-t-butyl-2,2'-bipyridine (dbutbipy)]. The solid state structures of five ruthenium complexes (1-5) were determined by X-ray crystallography. Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple in each case. Their interactions with DNA and BSA, and activity against four cell lines (L929, A549, MDA-MB-231 and MCF-7) were evaluated. Compounds 2, 6 through 9, interact with DNA which was comparable to the one observed for free chloroquine. The results of fluorescence titration revealed that these complexes strongly quenched the intrinsic fluorescence of BSA following a static quenching procedure. Binding constants (Kb) and the number of binding sites (n~1) were calculated using modified Stern-Volmer equations. The thermodynamic parameters ΔG at different temperatures were calculated and subsequently the values of ΔH and ΔS were also calculated, which revealed that hydrophobic and electrostatic interactions play a major role in the BSA-complex association. The MTT assay results indicated that complexes 2, 5 and 7 showed cytostatic effects at appreciably lower concentrations than those needed for cisplatin, chloroquine and doxorubicin.

  11. Aqueous interfaces with hydrophobic room-temperature ionic liquids: a molecular dynamics study.

    Science.gov (United States)

    Chaumont, A; Schurhammer, R; Wipff, G

    2005-10-13

    We report a molecular dynamics study of the interface between water and (macroscopically) water-immiscible room-temperature ionic liquids "ILs", composed of PF6(-) anions and butyl- versus octyl-substituted methylimidazolium+ cations (noted BMI+ and OMI+). Because the parameters used to simulate the pure ILs were found to exaggerate the water/IL mixing, they have been modified by scaling down the atomic charges, leading to better agreement with the experiment. The comparison of [OMI][PF6] versus [BMI][PF6] ILs demonstrates the importance of the N-alkyl substituent on the extent of solvent mixing and on the nature of the interface. With the most hydrophobic [OMI][PF6] liquid, the "bulk" IL phase is dryer than with the [BMI][PF6] liquid. At the interface, the OMI+ cations retain direct contacts with the bulk IL, whereas the more hydrophilic PF6(-) anions gradually dilute in the local water micro-environment and are thus isolated from the "bulk" IL. The interfacial OMI+ cations are ordered with their imidazolium moiety pointing toward the aqueous side and their octyl chains toward the IL side of the interface. With the [BMI][PF6] liquid, the system gradually evolves from an IL-rich to a water-rich medium, leading to an ill-defined interfacial domain with high intersolvent mixing. As a result, the BMI+ cations are isotropically oriented "at the interface". Because the imidazolium cations are more hydrophobic than the PF6(-) anions, the charge distribution at the interface is heterogeneous, leading to a positive electrostatic potential at the interface with the two studied ILs. Mixing-demixing simulations on [BMI][PF6]/water mixtures are also reported, comparing Ewald versus reaction field treatments of electrostatics. Phase separation is very slow (at least 30 ns), in marked contrast with mixtures involving classical organic liquids, which separate in less than 0.5 ns at the microscopic level. The results allow us to better understand the specificity of the aqueous

  12. Cytotoxicity of Ru(II) piano-stool complexes with chloroquine and chelating ligands against breast and lung tumor cells: Interactions with DNA and BSA.

    Science.gov (United States)

    Colina-Vegas, Legna; Villarreal, Wilmer; Navarro, Maribel; de Oliveira, Clayton Rodrigues; Graminha, Angélica E; Maia, Pedro Ivo da S; Deflon, Victor M; Ferreira, Antonio G; Cominetti, Marcia Regina; Batista, Alzir A

    2015-12-01

    The synthesis and spectroscopic characterization of nine π-arene piano-stool ruthenium (II) complexes with aromatic dinitrogen chelating ligands or containing chloroquine (CQ), are described in this study: [Ru(η(6)-C10H14)(phen)Cl]PF6 (1), [Ru(η(6)-C10H14)(dphphen)Cl]PF6 (2), [Ru(η(6)-C10H14)(bipy)Cl]PF6 (3), [Ru(η(6)-C10H14)(dmebipy)Cl]PF6 (4) and [Ru(η(6)-C10H14)(bdutbipy)Cl]PF6 (5), [Ru(η(6)-C10H14)(phen)CQ](PF6)2 (6), [Ru(η(6)-C10H14)(dphphen)CQ](PF6)2 (7), [Ru(η(6)-C10H14)(bipy)CQ](PF6)2 (8), [Ru(η(6)-C10H14)(dmebipy)CQ](PF6)2 (9): [1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dphphen), 2,2'-bipyridine (bipy), 5,5'-dimethyl-2,2'-bipyridine (dmebipy), and 4,4'-di-t-butyl-2,2'-bipyridine (dbutbipy)]. The solid state structures of five ruthenium complexes (1-5) were determined by X-ray crystallography. Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple in each case. Their interactions with DNA and BSA, and activity against four cell lines (L929, A549, MDA-MB-231 and MCF-7) were evaluated. Compounds 2, 6 through 9, interact with DNA which was comparable to the one observed for free chloroquine. The results of fluorescence titration revealed that these complexes strongly quenched the intrinsic fluorescence of BSA following a static quenching procedure. Binding constants (Kb) and the number of binding sites (n~1) were calculated using modified Stern-Volmer equations. The thermodynamic parameters ΔG at different temperatures were calculated and subsequently the values of ΔH and ΔS were also calculated, which revealed that hydrophobic and electrostatic interactions play a major role in the BSA-complex association. The MTT assay results indicated that complexes 2, 5 and 7 showed cytostatic effects at appreciably lower concentrations than those needed for cisplatin, chloroquine and doxorubicin. PMID:26277415

  13. Electrochemical behavior of aluminum foil in 1-alkyl-3-methylimidazolium tetrafiuoroborate ionic liquids electrolytes

    Institute of Scientific and Technical Information of China (English)

    PENG Chengxin; YANG Li; WANG Baofeng; ZHANG Zhengxi; LI Nan

    2006-01-01

    Aluminum (Al) foil is widely used as a current collector in lithium ion batteries, EDLCs and other electrochemical devices, and its electrochemical behavior in electrolytes has great effect on the cycle performances and safety of the electrochemical devices. In this work, corrosion behavior of Al foil in 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids and its electrolytes containing LiTFSI as salt were studied using cyclic voltammogram method. It was found that a passive film was firmly formed on the surface of Al foil after the anodic polarization in BMI-BF4 compared to those in EMI-BF4 and PMI-BF4.In addition, anodic polarization research showed that the passive film on Al surface in BMI-TFSI did not well exist. A good passive film formed on the surface of Al foil in BMI-BF4 was not broken down until the potential was up to 94.58 V. Moreover, EDX and XPS analysis showed that F and O exist on the Al surface after the anodic polarization in BMI-BF4, which indicated that a passive film like AIF3 and Al2O3 may be formed on its surface.

  14. Surface Adsorption and Micelle Formation of Polyoxyethylene-type Nonionic Surfactants in Mixtures of Water and Hydrophilic Imidazolium-type Ionic Liquid.

    Science.gov (United States)

    Misono, Takeshi; Okada, Kohei; Sakai, Kenichi; Abe, Masahiko; Sakai, Hideki

    2016-06-01

    The interfacial properties of polyoxyethylene alkyl ether-type nonionic surfactants (CnEm) were studied in a hydrophilic room-temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4), in the presence of water. These properties were assessed using static surface tension, pyrene fluorescence, and dynamic light scattering measurements. The interfacial properties were strongly dependent on the solution composition. Increased water concentration lowered the critical micelle concentration (cmc). The cmc was also affected by the lengths of both the alkyl and polyoxyethylene chains, but a greater impact was observed for the alkyl chain length. These results indicate that micellization occurs as a result of solvophobic interaction between surfactant molecules in the water/bmimBF4 mixed solutions, similar to aqueous surfactant systems. The cloud point phenomenon was observed for CnEm with a relatively low hydrophilic-lipophilic balance (HLB) value, and the relationship between the cloud point and water/bmimBF4 composition exhibited a convex upward curve. Furthermore, the mixing of bmimBF4 with water increased the surfactant solubility for water-rich compositions, suggesting that bmimBF4 acts as a chaotropic salt. PMID:27181249

  15. Temperature-induced microstructural changes in ionic liquid-based microemulsions.

    Science.gov (United States)

    Gao, Yanan; Li, Na; Hilfert, Liane; Zhang, Shaohua; Zheng, Liqiang; Yu, Li

    2009-02-01

    In the present contribution, results concerning the effect of temperature on the nonionic surfactant Triton X-100 based 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4)-in-cyclohexane and bmimBF4-in-toluene ionic liquid (IL) reverse microemulsions are reported. Dynamic light scattering (DLS) along with freeze-fracture transmission electron microscopy (FF-TEM) measurements revealed that the sizes of single microemulsion droplets increased with increasing temperature. However, a decreased temperature led to the appearance of droplet clusters, which have also been observed previously when the single microemulsion droplets were swollen by added bmimBF4 to a certain extent (Gao, Y. A.; Vogit, A.; Hilfert, L.; Sundmacher, K. ChemPhysChem, 2008, 9, 1603-1609). Compared to traditional aqueous microemulsions, IL microemulsions revealed relatively high temperature-independence. The droplet-shaped microstructure was always kept in a large range of temperature. The temperature-independence is ascribed to the temperature-insensitive electrostatic attraction between the solubilized bmimBF4 and Triton X-100, which was considered to be the driving force for solubilizing bmimBF4 into the cores of Triton X-100 aggregates. Two-dimensional rotating frame nuclear Overhauser effect (NOE) experiments (ROESY) further confirmed the microstructural change with temperature. PMID:19132875

  16. Catalytic activities of fungal oxidases in hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate-based microemulsion.

    Science.gov (United States)

    Zhou, Gui-Ping; Zhang, Yun; Huang, Xi-Rong; Shi, Chuan-Hong; Liu, Wei-Feng; Li, Yue-Zhong; Qu, Yin-Bo; Gao, Pei-Ji

    2008-10-01

    For hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]), an H(2)O-in-[BMIM][PF(6)] microemulsion could be formed in the presence of nonionic surfactant Triton X-100 (TX-100). In such a medium, both lignin peroxidase (LiP) and laccase could express their catalytic activity with the optimum molar ratio of H(2)O to TX-100 at 8.0 for LiP and >20 for laccase, and the optimum pH values at 3.2 for LiP and 4.2 for laccase, respectively. As compared with pure or water saturated [BMIM][PF(6)], in which the two oxidases had negligible catalytic activity due to the strong inactivating effect of [BMIM][PF(6)] on both enzymes, the use of the [BMIM][PF(6)]-based microemulsion had some advantages. Not only the catalytic activities of both fungal oxidases greatly enhanced, but also the apparent viscosity of the medium decreased. PMID:18602799

  17. Acetylcholine-like and trimethylglycine-like PTA (1,3,5-triaza-7-phosphaadamantane) derivatives for the development of innovative Ru- and Pt-based therapeutic agents.

    Science.gov (United States)

    Ferretti, Valeria; Fogagnolo, Marco; Marchi, Andrea; Marvelli, Lorenza; Sforza, Fabio; Bergamini, Paola

    2014-05-19

    The PTA N-alkyl derivatives (PTAC2H4OCOMe)X (1X: 1a, X = Br; 1b, X = I; 1c, X = PF6; 1d, X = BPh4), (PTACH2COOEt)X (2X: 2a, X = Br; 2b, X = Cl; 2c, X = PF6), and (PTACH2CH2COOEt)X (3X: 3a, X = Br; 3c, X = PF6), presenting all the functional groups of the natural cationic compounds acetylcholine or trimethylglycine combined with a P-donor site suitable for metal ion coordination, were prepared and characterized by NMR, ESI-MS, and elemental analysis. The X-ray crystal structures of 1d and 2c were determined. Ligands 1c, 2b, and 3c were coordinated to Pt(II) and Ru(II) to give the cationic complexes cis-[PtCl2(L)2]X2 and [RuCpCl(PPh3)(L)]X (L = 1, 2, 3, X = Cl or PF6) designed with a structure targeted for anticancer activity. The X-ray crystal structure of [CpRu(PPh3)(PTAC2H4OCOMe)Cl]PF6 (1cRu) was determined. The antiproliferative activity of the ligands and the complexes was evaluated on three human cancer cell lines. PMID:24801393

  18. Sub-picosecond time resolved infrared spectroscopy of high-spin state formation in Fe(II) spin crossover complexes

    DEFF Research Database (Denmark)

    Døssing, Anders Rørbæk; Wolf, Matthias M. N.; Gross, Ruth;

    2008-01-01

      The photoinduced low-spin (S = 0) to high-spin (S = 2) transition of the iron(II) spin-crossover systems [Fe(btpa)](PF6)2 and [Fe(b(bdpa))](PF6)2 in solution have been studied for the first time by means of ultrafast transient infrared spectroscopy at room temperature. Negative and positive...... infrared difference bands between 1000 and 1065 cm-1 that appear within the instrumental system response time of 350 fs after excitation at 387 nm display the formation of the vibrationally unrelaxed and hot high-spin 5T2 state. Vibrational relaxation is observed and characterized by the time constants 9.......4 ± 0.7 ps for [Fe(btpa)](PF6)2/acetone and 12.7 ± 0.7 ps for both [Fe(btpa)](PF6)2/acetonitrile and [Fe(b(bdpa)](PF6)2/acetonitrile. Vibrational analysis has been performed via DFT calculations of the low-spin and high-spin state normal modes of both compounds as well as their respective infrared...

  19. Electrochemical behavior of labetalol at an ionic liquid modified carbon paste electrode and its electrochemical determination

    Directory of Open Access Journals (Sweden)

    Zhang Yan-Mei

    2013-01-01

    Full Text Available Electrochemical behavior of labetalol (LBT at carbon paste electrode (CPE and an ionic liquid1-benzyl-3-methylimidazolehexafluorophosphate([BnMIM]PF6modified carbon paste electrode([BnMIM]PF6/CPEin Britton-Robinson buffer solution (pH 2.0 was investigated by cyclic voltammetry (CV and square wave voltammetric (SWV. The experimental results showed that LBT at both the bare CPE and [BnMIM]PF6/CPEshowed an irreversible oxidation process, but at [BnMIM]PF6/CPE its oxidation peak current increased greatly and the oxidation peak potential shifted negatively. The electrode reaction process is a diffusion-controlled process involving one electron transferring accompanied by a participation of one proton at [BnMIM]PF6/CPE. At the same time, the electrochemical kinetic parameters were determined. Under the optimized electrochemical experimental conditions, the oxidation peak currents were proportional to LBT concentration in the range of 7.0 x 10-6-1.0 x 10-4 mol L-1 with the limit of detection(LOD, S/N=3 of 4.810 x 10-8 mol L-1and the limit of quantification(LOQ, S/N=10 of 1.60 x 10-7 mol L-1, respectively. The proposed method was successfully applied in the determination of LBT content in commercial tablet samples.

  20. Determination of three physical properties of quinoline ionic liquids with hexafluorophosphate

    Directory of Open Access Journals (Sweden)

    Tang Dan

    2016-01-01

    Full Text Available Densities of one acidic ionic liquid (IL Quinolinum hexafluorophosphate ([HBpy][PF6], and four neutral dicationic ionic liquids (ILs based on quinoline and hexafluoro-phosphate and linked with poly(ethylene glycol (PEG: ([PEG200-DIL][PF6]2, [PEG400-DIL][PF6]2, [PEG800-DIL][PF6]2 and [PEG1000-DIL][PF6]2 were determined. In addition, the solubilities of six ILs in six lower alcohols, water, acetonitrile and diethyl ether were measured at 288.15 K; and the hydroscopicity of above five ILs were measured at the temperature of 298.15 K and relative humidity of 79% for 24 h. Densities of five ionic liquids were determined between 283.15 and 333.15 K. Then the densities of five binary system (ILs/acetonitrile were explored between 283.15 and 333.15 K, the type of the ionic liquid, the concentration of five ILs in CH3CN, and the effect of temperature on the binary systems, were correlated with the measured data.

  1. Phase transition of carbonate solvent mixture solutions at low temperatures

    Science.gov (United States)

    Okumura, Takefumi; Horiba, Tatsuo

    2016-01-01

    The phase transition of carbonate solvent mixture solutions consisting of ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and LiPF6 salt have been studied for improving the low temperature performance of lithium-ion batteries. The Li ion conductivity at 25 °C was maximum at x = 0.3 in a series of 1 M LiPF6 mixed carbonate solvents compositions consisting of ECxDMC0.5-0.5xEMC0.5-0.5x (x = 0 to 0.6), while the maximum tended to shift to x = 0.2 as the temperature lowered. The differential scanning calorimetry results showed that the freezing temperature depressions of EC in the 1 M LiPF6 solution were larger than those of the DMC or EMC. The chemical shift of 7Li nuclear magnetic resonance changed from a constant to increasing at around x = 0.3, which could be reasonably understood by focusing on the change in solvation energy calculated using Born equation. However, in the region of a high EC concentration of over x = 0.3 (EC/LiPF6 > 4) in the 1 M LiPF6 solution, the free EC from the solvation to the lithium ions seems to reduce the freezing temperature depression of the EC, and thus, decreases the ionic conductivity of the solution at low temperatures, due to the EC freezing.

  2. o-, m-, and p-Pyridyl isomer effects on construction of 1D loop-and-chains: Silver(I) coordination polymers with Y-type tridentate ligands

    Science.gov (United States)

    Kim, Jeong Gyun; Cho, Yoonjung; Lee, Haeri; Lee, Young-A.; Jung, Ok-Sang

    2016-10-01

    Self-assembly of silver(I) hexafluorophosphate with unique Y-type tridentate ligands (2,6-bis[(2-picolinoyloxy-5-methylphenyl)methyl]-p-tolylpicolinate (o-L), 2-nicotinoyloxy- (m-L), and 2-isonicotinoyloxy- (p-L)) produces single crystals consisting of 1D loop-and-chain coordination polymers of [Ag(o-L)](PF6)·Me2CO·CHCl3, [Ag(m-L)](PF6)·Me2CO, and [Ag3(p-L)2](PF6)3·2H2O·2C2H5OH·4CH2Cl2 with quite different trigonal prismatic, trigonal, and linear silver(I) coordination geometry, respectively. Coordinating ability of the three ligands for AgPF6 is in the order of p-L > o-L > m-L. The solvate molecules of [Ag(o-L)](PF6)·Me2CO·CHCl3 can be removed, and be replaced reversibly in the order of acetone ≫ chloroform ≈ dichloromethane ≫ benzene, without destruction of its skeleton.

  3. Influence of the organization of water-in-ionic liquid microemulsions on the size of silver particles during photoreduction.

    Science.gov (United States)

    Harada, Masafumi; Yamada, Masako; Kimura, Yoshifumi; Saijo, Kenji

    2013-09-15

    Metal particles of silver (Ag) have been synthesized by the photoreduction of silver nitrate (AgNO3) in water-in-ionic liquid (IL) microemulsions consisting of nonionic surfactant Tween 20 or Triton X-100, water and ionic liquid, 1-octyl-3-methylimidazolium hexafluorophosphate ([OMIm][PF6]). The formation of microemulsions as well as Ag particles produced by the photoreduction has been investigated by UV-vis, cryo-TEM, small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) measurements. At the early stage of Ag particle formation under ambient pressure, the size of Ag particles in water/[OMIm][PF6]/TX-100 microemulsions was slightly larger than that in water/[OMIm][PF6]/Tween20 microemulsions. With an increase in photoirradiation time beyond 30 min, precipitation of larger Ag aggregates occurred. In contrast to the preparation under ambient pressure, the growth of Ag particles and aggregates was suppressed in preparing under high pressure (25 MPa) of CO2, leading to no precipitation of Ag aggregates. The average diameters of the finally-obtained metallic Ag particles prepared under high pressure of CO2 in water/[OMIm][PF6]/Tween20 and water/[OMIm][PF6]/TX-100 microemulsions were estimated from cryo-TEM to be 3.7 nm and 2.8 nm, respectively. By using Guinier plots at q (microemulsions. PMID:23791230

  4. Photoinduced electron transfer between 2-methylanthraquinone and triethylamine in an ionic liquid: time-resolved EPR and transient absorption spectroscopy study.

    Science.gov (United States)

    Zhu, Guanglai; Wang, Yu; Fu, Haiying; Xu, Xinsheng; Cui, Zhifeng; Ji, Xuehan; Wu, Guozhong

    2015-02-25

    Photoinduced electron transfer between 2-methylanthraquinone (MeAQ) and triethylamine (TEA) in a room-temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), was investigated by comparing the time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy and the transient absorption spectroscopy. The results of TR-EPR spectroscopy, in which MeAQ was 8 mmol L(-1) and TEA was 150 mmol L(-1), indicated that the transient radical would exist longer time in [bmim][PF6] than in acetonitrile. At the delay time of 8 μs after laser excitation, the TR-EPR signal transformed from an emissive peak into an absorptive peak when the experiment was performed in [bmim][PF6]. The results of the transient absorption spectroscopy, in which MeAQ was 0.1 mmol L(-1) and TEA was 2.2 mmol L(-1), showed that the efficiency and the rate of the photoinduced electron transfer reaction in [bmim][PF6] were obviously lower than that in acetonitrile. It was concluded that various factors, such as concentration, viscosity and local structural transformation of the solution, have an influence on the process of photoinduced electron transfer in [bmim][PF6].

  5. Department of Nuclear Radiospectroscopy - Overview

    International Nuclear Information System (INIS)

    Research at the Department of Nuclear Radiospectroscopy concerns various aspects of the NMR and its applications to solids and to biosystems. The research activity covers: investigation of molecular dynamics and structures in solids using NMR spectroscopy, and investigation of humans, animals and plants using NMR imaging and localized spectroscopy. The MR Laboratory is equipped with a 7.05 T wide bore vertical superconducting magnet (SCM) with a pulse spectrometer. It allows to measure of deuteron NMR spectra at T ≥ 5 K. NMR high resolution spectra for 29Si, 11B, 27Al and 31P nuclei can be measured using MAS-NMR probe heads. The Magnetic Resonance Imaging Laboratory is equipped with 360 MHz MR microscope based on a 8.4 T narrow bore SCM and a MRI/MRS system based on a 2 T, 31 cm horizontal bore SCM. Magnetic Resonance Laboratory: Molecular reorientation studies aimed at disclosing tunnelling rotation and structural research of amorphous solids were main topics. Realisation of these projects required a development of our NMR pulse spectrometer and theoretical methods. The spectrometer was put into operation in 1997. Recent development was done in the data acquisition by the introduction of a new A/D converter and a pulse programmer. Tunnelling and reorientations of mixed isotope rotors are currently the most interesting topics. For a given deuteration rate of an ammonium compound it was anticipating that deuteron NMR spectra consist of weighted contributions from the following isotopomers: NH3D+, NH2D2+, NH3D+ and ND4+. Each isotopomer provides a characteristic spectral component due to its mobility. Measurements were performed for a number of partially deuterated samples of (NH4)2S2O8, NH4ClO4, NH4PF6, (NH4)2ZnCl4 and (NH4)2TeCl6 in the T = 5-100 K. The spectra of NH3D+ ions are particularly interesting. A new effect of an isotope ordering was observed. The structural investigations of amorphous solids by NMR technique have obtained a major boost this year due a

  6. The low-temperature phase of morpholinium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Tadeusz Lis

    2008-04-01

    Full Text Available The crystal structure of the low-temperature form of the title compound, C4H10NO+·BF4−, was determined at 80 K. Two reversible phase transitions, at 158/158 and 124/126 K (heating/cooling, were detected by differential scanning calorimetry for this compound, and the sequence of phase transitions was subsequently confirmed by single-crystal X-ray diffraction experiments. The asymmetric unit at 80 K consists of three BF4− tetrahedral anions and three morpholinium cations (Z′ = 3. Hydrogen-bonded morpholinium cations form chains along the [100] direction. The BF4− anions are connected to these chains by N—H...F hydrogen bonds. In the crystal structure, two different layers perpendicular to the [001] direction can be distinguished, which differ in the geometry of the hydrogen bonds between cationic and anionic species.

  7. Mesoporous Silica Materials Synthesized via Sol-Gel Methods Modified with Ionic Liquid and Surfactant Molecules

    Institute of Scientific and Technical Information of China (English)

    Cun-ying Xu; Ru-lan Tang; Yi-xin Hu; Peng-xiang Zhang

    2008-01-01

    Mesoporous silica materials were synthesized via a sol-gel method employing a room temperature ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4]) as a new solvent medium and further modified with surfactant (hexadecyl-trimethyl-ammonium bromide, CTAB) as a pore templating material. The synthesized samples were characterized by the transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption techniques. The results indicated that the mesoporous silica synthesized by using [bmim][BF4] and CTAB as mixed templates showed better mesostructural order and smaller pore size, compared with mesoporous silica materials synthesized by using single [bmim][BF4]as template under the same conditions. This indicates that the presence of surfactant can affect the microstructures of silica prepared by the present synthesis method.

  8. 直接甲醇燃料电池用离子液体复合膜的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    苗睿瑛; 方勇; 唐玲; 李建玲; 王新东

    2009-01-01

    制备了直接甲醇燃料电池用的2种离子液体([α-MPyH][Tfa]和[EMIm][BF4])复合膜,并对二者的微观形貌以及电化学特征予以表征.阻抗测试结果表明,[EMIm][BF4]复合膜的电导率高于[α-MPyH][Tfa]复合膜,计时电流法对二者阻醇性能研究结果表明,[EMIm][BF4]复合膜的阻醇性能也好于[α-MPyH][Tfa]复合膜.

  9. A comparative study of room temperature ionic liquids and their organic solvent mixtures near charged electrodes

    Science.gov (United States)

    Vatamanu, Jenel; Vatamanu, Mihaela; Borodin, Oleg; Bedrov, Dmitry

    2016-11-01

    The structural properties of electrolytes consisting of solutions of ionic liquids in a polar solvent at charged electrode surfaces are investigated using classical atomistic simulations. The studied electrolytes consisted of tetraethylammonium tetrafluoroborate (NEt4-BF4), 1-ethyl-3-methylimidazolium tetrafluoroborate (c2mim-BF4) and 1-octyl-3-methylimidazolium tetrafluoroborate (c8mim-BF4) salts dissolved in acetonitrile solvent. We discuss the influence of electrolyte concentration, chemical structure of the ionic salt, temperature, conducting versus semiconducting nature of the electrode, electrode geometry and surface roughness on the electric double layer structure and capacitance and compare these properties with those obtained for pure room temperature ionic liquids. We show that electrolytes consisting of solutions of ions can behave quite differently from pure ionic liquid electrolytes.

  10. Acceleration effect of ionic liquids on polycyclotrimerization of dicyanate esters

    Directory of Open Access Journals (Sweden)

    A. Fainleib

    2016-09-01

    Full Text Available The polycyclotrimerization reaction of dicyanate ester of bisphenol E (DCBE in the presence of varying amounts (from 0.5 to 5 wt% of 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIm][BF4] ionic liquid has been investigated using differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR techniques, after a curing stage at 150 °C for 6 h. It is noteworthy that an amount of [OMIm][BF4] as low as 0.5 wt% accelerates dramatically the thermal curing process leading to the formation of a polycyanurate network. The conversion of DCBE increased with increasing [OMIm][BF4] content in the temperature range studied. A reaction mechanism associated with the ionic liquid-catalyzed DCBE polycyclotrimerization is newly proposed via the involvement of a [CN]δ+–[OMIm]δ– complex as a key intermediate.

  11. 反气相色谱法表征离子液体1-丁基-3-甲基咪唑四氟硼酸盐的溶解度参数%Determination of the solubility parameter of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate by inverse gas chromatography

    Institute of Scientific and Technical Information of China (English)

    马晓红; 王强; 李晓萍; 唐军; 张正方

    2015-01-01

    Thermodynamic properties of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate([ BMIM ] BF4 )were determined via inverse gas chromatography( IGC). Two groups of solvents with different chemical natures and polarities were used to obtain information about[ BMIM]BF4-solvent interactions. The specific retention volume,molar heat of sorption,weight fraction activity coefficient,Flory-Huggins interaction param-eter as well as solubility parameter were also determined in a temperature range of 333-373 K. The results showed that the selected solvents n-C10 to n-C12,carbon tetrachloride,cyclohexane and toluene were poor sol-vents for[BMIM]BF4,while dichloromethane,acetone,chloroform,methyl acetate,ethanol and methanol were favorite solvents for[BMIM]BF4. In addition,the solubility parameter of[BMIM]BF4 was determined as 23. 39( J/cm3 )0. 5 by the extrapolation at 298 K. The experiment proved that IGC was a simple and accurate method to obtain the thermodynamic properties of ionic liquids. This study could be used as a reference to the application and research of the ionic liquids.%采用反气相色谱法(IGC)表征了离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)在333~373 K 温度范围内的热力学参数。使用两组不同化学结构和性质的探针分子测定了[ BMIM]BF4与溶剂之间的相互作用力。根据探针分子的保留时间计算得到探针分子与[ BMIM]BF4之间的摩尔吸附焓、质量分数活度系数、Flory-Huggins相互作用参数和[ BMIM]BF4的溶解度参数。结果表明,所选溶剂中 n-C10、n-C11、n-C12、四氯化碳,环己烷和甲苯为[BMIM]BF4的不良溶剂;二氯甲烷、丙酮、氯仿、乙酸甲酯、乙醇、甲醇为[BMIM]BF4的良溶剂。运用外推法得到了[HMIM]BF4在室温(298.15K)时的溶解度参数为23.39(J/cm3)0.5。实验结果证明 IGC 法是一种简便准确的获得离子液体热力学参数的方法。本研究为离子液体的应用及相

  12. Preparation and Characterization of a Novel Benzimidazolium Br(φ)nsted Acid Ionic Liquid and Its Application in the Synthesis of Arylic Esters

    Institute of Scientific and Technical Information of China (English)

    WANG,Yuan-Yuan; LI,Wei; XU,Cheng-Di; DAI,Li-Yi

    2007-01-01

    A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate ([Hebim]BF4) with functional benzimidazolium cation was synthesized and characterized by 1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters.Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.

  13. Hexagonal boron nitride hollow capsules with collapsed surfaces: Chemical vapor deposition with single-source precursor ammonium fluoroborate

    Science.gov (United States)

    Xiaopeng, Li; Jun, Zhang; Chao, Yu; Xiaoxi, Liu; Saleem, Abbas; Jie, Li; Yanming, Xue; Chengchun, Tang

    2016-07-01

    SBA-15 (mesoporous SiO2) is used to stabilize and transfer F- in the NH4BF4 CVD reaction for the first time, and a large-scale crystalline h-BN phase can be prepared. We successfully fabricate hollow h-BN capsules with collapsed surfaces in our designed NH4BF4 CVD system. Optimum temperature conditions are obtained, and a detailed formation mechanism is further proposed. The successful SBA-15-assisted NH4BF4 CVD route is of importance and enriches the engineering technology in the h-BN single-source CVD reaction. Project supported by the National Natural Science Foundation of China (Grant Nos. 51332005, 51372066, 51172060, 51202055, and 21103056).

  14. Generalizations of the Fuoss Approximation for Ion Pairing

    CERN Document Server

    Zhu, P; Pratt, L R; Papadopoulos, K D

    2010-01-01

    An elementary statistical observation identifies generalizations of the Fuoss approximation for the probability distribution function that describes ion clustering in electrolyte solutions. By exploiting measurable inter-ionic correlation functions, this generalization is correct at the closest pair distances, extends beyond primitive electrolyte solution models, and includes non-ionic interactions and solvation effects. The proposed generalization is relevant also for the computational analysis of bi-molecular reactive processes in solution. Comparisons with direct numerical simulation results show that the simplest generalization is accurate for a slightly supersaturated solution of tetraethylammonium tetrafluoroborate in propylene carbonate ([tea][BF4]/PC), and also for a primitive model associated with the [tea][BF4]/PC results. For [tea][BF4]/PC, the atomically detailed results identify solvent-separated nearest-neighbor ion-pairs. This generalization is examined also for the ionic liquid 1-butyl-3-methy...

  15. Structural, NMR, and EPR studies of S = (1)/(2) and S = (3)/(2) Fe(III) bis(4-cyanopyridine) complexes of dodecasubstituted porphyrins.

    Science.gov (United States)

    Yatsunyk, Liliya A; Walker, F Ann

    2004-01-26

    The NMR and EPR spectra for three complexes, iron(III) octamethyltetraphenylporphyrin bis(4-cyanopyridine) perchlorate, [FeOMTPP(4-CNPy)(2)]ClO(4), and its octaethyl- and tetra-beta,beta'-tetramethylenetetraphenylporphyrin analogues, [FeOETPP(4-CNPy)(2)]ClO(4) and [FeTC(6)TPP(4-CNPy)(2)]ClO(4), are presented. The crystal structures of two different forms of [FeOETPP(4-CNPy)(2)]ClO(4) and one form of [FeOMTPP(4-CNPy)(2)]ClO(4) are also reported. Attempts to crystallize [FeTC(6)TPP(4-CNPy)(2)]ClO(4) were not successful. The crystal structure of [FeOMTPP(4-CNPy)(2)]ClO(4) reveals a saddled porphyrin core, a small dihedral angle between the axial ligand planes, 64.3 degrees, and an unusually large tilt angle (24.4 degrees ) of one of the axial 4-cyanopyridine ligands with respect to the normal to the porphyrin mean plane. There are 4 and 2 independent molecules in the asymmetric units of [FeOETPP(4-CNPy)(2)]ClO(4) crystallized from CD(2)Cl(2)/dodecane (1-4) and CDCl(3)/cyclohexane (5-6), respectively. The geometries of the porphyrin cores in 1-6 vary from purely saddled to saddled with 15% ruffling admixture. In all structures, the Fe-N(p) distances (1.958-1.976 A) are very short due to strong nonplanar distortion of the porphyrin cores, while the Fe-N(ax) distances are relatively long ( approximately 2.2 A) compared to the same distances in S = (1)/(2) bis(pyridine)iron(III) porphyrin complexes. An axial EPR signal is observed (g( perpendicular ) = 2.49, g( parallel ) = 1.6) in frozen solutions of both [FeOMTPP(4-CNPy)(2)]ClO(4) and [FeTC(6)TPP(4-CNPy)(2)]ClO(4) at 4.2 K, indicative of the low spin (LS, S = (1)/(2)), (d(yz)d(xz))(4)(d(xy))(1) electronic ground state for these two complexes. In agreement with a recent publication (Ikeue, T.; Ohgo, Y.; Ongayi, O.; Vicente, M. G. H.; Nakamura, M. Inorg. Chem. 2003, 42, 5560-5571), the EPR spectra of [FeOETPP(4-CNPy)(2)]ClO(4) are typical of the S = (3)/(2) state, with g values of 5.21, 4.25, and 2.07. A small amount of LS species with g = 3.03 is also present. However, distinct from previous conclusions, large negative phenyl-H shift differences delta(m) - delta(o) and delta(m) - delta(p) in the (1)H NMR spectra indicate significant negative spin density at the meso-carbons, and the larger than expected positive average CH(2) shifts are also consistent with a significant population of the S = 2 Fe(II), S = (1)/(2) porphyrin pi-cation radical state, with antiferromagnetic coupling between the metal and porphyrin unpaired electrons. This is the first example of this type of porphyrin-to-metal electron transfer to produce a partial or complete porphyrinate radical state, with antiferromagnetic coupling between metal and macrocycle unpaired electrons in an iron porphyrinate. The kinetics of ring inversion were studied for the [FeOETPP(4-CNPy)(2)]ClO(4) complex using NOESY/EXSY techniques and for the [FeTC(6)TPP(4-CNPy)(2)]ClO(4) complex using DNMR techniques. For the former, the free energy of activation, deltaG, and rate of ring inversion in CD(2)Cl(2) extrapolated to 298 K are 63(2) kJ mol(-)(1) and 59 s(-)(1), respectively, while for the latter the rate of ring inversion at 298 K is at least 4.4 x 10(7) s(-)(1), which attests to the much greater flexibility of the TC(6)TPP ring. The NMR and EPR data are consistent with solution magnetic susceptibility measurements that show S = (3)/(2) in the temperature range from 320 to 180 K for [FeOETPP(4-CNPy)(2)](+), while both [FeOMTPP(4-CNPy)(2)](+) and [FeTC(6)TPP(4-CNPy)(2)](+) change their spin state from S = (3)/(2) at room temperature to mainly LS (S = (1)/(2)) upon cooling to 180 K. PMID:14731040

  16. (2,2′-Bipyridine-κ2N,N′bromido(1,4,7-trithiacyclononane-κ3S,S′,S′′ruthenium(II hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    José A. Fernandes

    2011-02-01

    Full Text Available The title compound, [RuBr(C10H8N2(C6H12S3]PF6 or [RuBr(bpy([9]aneS3]PF6 ([9]aneS3 is 1,4,7-trithiacyclononane and bpy is 2,2′-bipyridine, exhibits a very similar octahedral coordination geometry for the Ru2+ atom to that of its [RuCl(bpy([9]aneS3]+ analogue, with only the chloride ligand being substituted by a bromide ligand. The presence of a PF6− anion (alongside with the coordinated bromide ligand promotes the existence of an extensive network of weak C—H...X (X = F, Br interactions.

  17. Sensitive determination of Amaranth in drinks by highly dispersed CNT in graphene oxide "water" with the aid of small amounts of ionic liquid.

    Science.gov (United States)

    Wang, Meiling; Sun, Yinlu; Yang, Xiongbo; Zhao, Jianwei

    2015-07-15

    Graphene oxide (GO) is a pH-dependent amphiphile. In this paper, it was found that carbon nanotubes (CNTs) can be highly dispersed in graphene oxide "water" with the aid of prototype ionic liquid of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]). The introduction of [BMIM][PF6] not only can minimize the defects of poor electrical conductivity of GO, but also can improve the dispersibility of CNT in water. Hence, a new composite of CNT/GO-[BMIM][PF6] with high dispersibility and strong conductivity was presented for the first time and employed in the sensitive determination of Amaranth in soft drinks. The detection limit achieved (0.1 nM) is much lower than the guideline values in soft drinks. The ease of preparation, low background current, high sensitivity and stability can create novel avenues and applications for fabricating robust sensors for determination of other azo dyes in foods.

  18. Effects of solvents and salt on the thermal stability of lithiated graphite used in lithium ion battery.

    Science.gov (United States)

    Wang, Qingsong; Sun, Jinhua; Chen, Chunhua

    2009-08-15

    The thermal stability of lithiated graphite in the presence of solvents, electrolytes and LiPF(6) salt was studied using C80 micro-calorimeter. The presence of cyclic carbonates or linear carbonates increases the activity of Li(x)C(6)-solvent coexisting system, especially for the Li(x)C(6)-linear carbonates one. LiPF(6) was detected that it increases the activity greatly of its coexisting system with lithiated graphite. The coexisting system of Li(x)C(6) with the electrolyte of LiPF(6)/ethylene carbonate+diethyl carbonate shows less thermal stability, which is attributed to the activity between diethyl carbonate and Li(x)C(6). This also agrees with the experiment result of Li(x)C(6)-diethyl carbonate coexisting system. PMID:19261386

  19. Formation of a robust and stable film comprising ionic liquid and polyoxometalate on glassy carbon electrode modified with multiwalled carbon nanotubes: Toward sensitive and fast detection of hydrogen peroxide and iodate

    International Nuclear Information System (INIS)

    A robust and stable film comprising n-octylpyridinum hexafluorophosphate ([C8Py][PF6]) and 1:12 phosphomolybdic acid (PMo12) was prepared on glassy carbon electrodes modified with multiwall carbon nanotubes (GCE/MWCNTs) by dip-coating. The cyclic voltammograms of the GCE/MWCNTs/[C8Py][PF6]-PMo12 showed three well-defined pairs of redox peaks due to the PMo12 system. The surface coverage for the immobilized PMo12 and the average values of the electron transfer rate constant for three pairs of redox peaks were evaluated. The GCE/MWCNTs/[C8Py][PF6]-PMo12 showed great electrocatalytic activity towards the reduction of H2O2 and iodate. The kinetic parameters of the catalytic reduction of hydrogen peroxide and iodate at the electrode surface and analytical features of the sensor for amperometric determination of hydrogen peroxide and iodate were evaluated.

  20. Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: Synthesis, crystal structure analysis and spectroscopic studies

    Science.gov (United States)

    Tao, Li; Miao, Qian; Tehrani, Alireza Azhdari; Hajiashrafi, Taraneh; Hu, Mao-Lin; Morsali, Ali

    2016-08-01

    Three Ru(II) half-sandwich complexes containing (N,N)-bound Schiff-base ligands, [(η6-C6H6) RuCl(L1)]PF6 (1) L1 = (E)-1-(6-methylpyridin-2-yl)-N-(p-tolyl)methanimine, [(η6-p-cymene)RuCl(L1)]PF6 (2) and [(η6-p-cymene)RuCl(L2)]PF6(3) L2 = (E)-1-(6-bromopyridin-2-yl)-N-(p-tolyl)methanimine, were synthesized, characterized and their supramolecular structures were analyzed. The crystal packing of these compounds was studied using geometrical analysis and Hirshfeld surface analysis. The fluorescence behavior of these compounds was also studied. TD-DFT calculations were carried out to better understand the fluorescence properties of complexes 1-3. These compounds could be promising for the design of organometallic dye systems.

  1. 离子液体中电沉积铁工艺的研究%A Study of Electrodepositing Metallic Fe from Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    徐加民; 安茂忠; 苏彩娜; 杨培霞

    2009-01-01

    The electrodeposition of metallic iron from [BMIM]BF_4 ionic liquid containing Fe~(2+) was investigated on coppersubstrates. The influences of bath composition and operation conditions of the process on the appearance of iron coatings were discussed, and the optimum technological conditions determined, under which a bright, appearance-uniform and fine coating was obtained. The polarization curve indicates that the electrodeposition of metallic iron in the [BMIM] BF_4-Fe (BF_4)_2 electrolyte is controlled by diffusion and irreversible growth process. SEM images of the iron deposits show that the crystallite is small and compact. X-ray diffraction(XRD) analysis approves that the obtained deposits are of pure Fe, and the grains have a preferred orientation along (110) crystal plane.%在舍有Fe~(2+)的离子液体1-丁基-3-甲基四氟硼酸盐([BMIM]BF_4)电解液中,研究了金属铁的电沉积工艺.讨论了镀液组成及工艺条件对镀层外观质量的影响,确定了较佳的电镀工艺条件.在该工艺条件下,得到了结晶细致、外观均匀、光亮的金属铁镀层.稳态极化曲线测试表明:在[BMIM]BF_4-Fe(BF_4)_2体系中,铁的电沉积是受扩散控制的非可逆电极过程.扫描电子显微镜(SEM)观察镀层的微观形貌显示金属铁的结晶细小.XRD分析证实:镀层为纯铁,沉积的铁的结晶发生明显的择优取向.

  2. Molecular Simulation on Microstructure of Ionic Liquids in Capture of CO2

    Institute of Scientific and Technical Information of China (English)

    YUE Zhen-uo; LIU Xiao-min; ZHAO Yu-ling; ZHANG Xiao-chun; LU Xing-mei; ZHANG Suo-jiang

    2011-01-01

    Molecular dynamic simulation is used to study the microstructure of four kinds of ionic liquids (ILs),[Emim]PF6,[Emim][Tf2N],[PC6,6,6,14]PF6 and [PC6,6,6,14][Tf2N] in the capture process of CO2.Radial distribution function (RDF) and spatial distribution function (SDF) are used to analyze the microscopic properties of these systems.The calculated results show that the space distribution of CO2 around ILs determines the capability of ionic liquids for capturing CO2.Based on the analysis of SDF,CO2 and PF6- are overlapped partially around [Emim]+ in [Emim]PF6-CO2 mixture.When the anion is [Tf2N]-,cations are mainly distributed on one side of [Tf2N]- near N atom,and CO2 is concentrated on two sides near the fluoroalkylgroup (-CF3),and there is little overlapped district between cation and CO2.In [PC6,6,6,14]PF6-CO2 mixture,layered structure is found and CO2 is much nearer to PF6- than [PC6,6,6,14]+.Based on the analysis of RDF,in the phosphonium-based ILs,the highest distribution densities of anions and CO2 around cations are about 6 and 3 times as their average ones respectively,while in the imidazolium-based ILs,they are about 3 and 2 respectively,this means that the distributions of CO2 and anions around the imidazolium-based ILs are more evenly distributed than those around the phosphonium-bascd ILs.

  3. Oxidative stress in spring barley and common radish exposed to quaternary ammonium salts with hexafluorophosphate anion.

    Science.gov (United States)

    Biczak, Robert; Telesiński, Arkadiusz; Pawłowska, Barbara

    2016-10-01

    Quaternary ammonium salts (QAS), including ionic liquids (ILs), constitute a huge group of substances, which due to their desirable physical and chemical properties still attracts great interest in many industrial sectors. An increased concentration of this compound in the environment may lead to the contamination of the natural environment and may pose a potential threat to all organisms, including terrestrial higher plants. The present study demonstrates the interaction of three QAS with PF6(-) anions - tetramethylammonium [TMA][PF6], tetrabutylammonium [TBA][PF6], and tetrahexylammonium [THA][PF6] hexafluorophosphates - and its impact on the physiological and biochemical changes in spring barley seedlings and common radish plants. A similar study was also carried out by introducing the inorganic salt - ammonium hexafluorophosphate [A][PF6] to the soil; the results showed the soil became highly toxic to both plants. All the salts used led to significant changes in the metabolism of both spring barley and common radish which can be evidenced, for example, by a decrease in the content of chlorophyll a (Chla), chlorophyll b (Chlb), and total chlorophyll (Chla + b), as well as carotenoids (Car). The decrease in assimilation pigments was linearly correlated with an increasing concentration of QAS in the soil. QAS and [A][PF6] led to the formation of oxidative stress in both experimental plants, as evidenced by an increase in malondialdehyde (MDA) content in their cells and the changes in H2O2 level. In response to stress, the plants synthesized enzymatic free radicals (ROS) scavengers that lead to changes in the activity of superoxide dismutase (SOD) and catalase (CAT), as well as significantly increased peroxidase (POD) activity. A decrease in the content of assimilation pigments and an increased POD activity are the most reliable indices of oxidative stress, and concurrently the signs of premature plants aging. Common radish proved to be more resistant to the

  4. Solvation of uranyl(II) and europium(III) cations and their chloro complexes in a room-temperature ionic liquid. A theoretical study of the effect of solvent "humidity".

    Science.gov (United States)

    Chaumont, Alain; Wipff, Georges

    2004-09-20

    We report a molecular dynamics study of the solvation of the UO2(2+) and Eu3+ cations and their chloro complexes in the [BMI][PF6][H2O] "humid" room-temperature ionic liquid (IL) composed of 1-butyl-3-methylimidazolium+ and PF6- ions and H2O in a 1:1:1 ratio. When compared to the results obtained in dry [BMI][PF6], the present results reveal the importance of water. The "naked" cations form UO2(H2O)5(2+) and Eu(H2O)9(3+) complexes, embedded in a shell of 7 and 8 PF6- anions, respectively. All studied UO2Cln(2-n) and EuCln(3-n) chloro complexes remain stable during the dynamics and coordinate additional H2O molecules in their first shell. UO2Cl4(2-) and EuCl6(3-) are surrounded by an "unsaturated" water shell, followed by a shell of BMI+ cations. According to an energy component analysis, the UO2Cl4(2-) and EuCl6(3-) species, intrinsically unstable toward dissociation, are more stable than their less halogenated analogues in the IL solution, due to the solvation forces. The different chloro species also interact better with the humid than with the dry IL, which hints at the importance of solvent humidity to improve their solubility. Humidity markedly modifies the local ion environment, with major consequences as far as their spectroscopic properties are concerned. We finally compare the aqueous interface of [BMI][PF6] and [OMI][PF6] ionic liquids, demonstrating the importance of imidazolium substituents (N-butyl versus N-octyl) to the nature of the interface and miscibility with water.

  5. Determination of the electrochemical performance and stability of the lithium-salt, lithium 4,5-dicyano-2-(trifluoromethyl) imidazolide, with various anodes in Li-ion cells

    Science.gov (United States)

    Paillet, Sabrina; Schmidt, Gregory; Ladouceur, Sébastien; Fréchette, Joël; Barray, Francis; Clément, Daniel; Hovington, Pierre; Guerfi, Abdelbast; Vijh, Ashok; Cayrefourcq, Ian; Zaghib, Karim

    2015-12-01

    The electrochemical performance and stability of lithium 4,5-dicyano-2-(trifluoromethyl) imidazolide (LiTDI), which is a promising lithium salt for electrolytes in lithium-ion batteries, are discussed. The power capability of LiTDI in EC/DEC (3/7 v/v) in half cells was evaluated with standard anodes used in the lithium-ion battery industry: graphite and Li4Ti5O12 (LTO). The effects of two additives, vinylene carbonate (VC) and fluoro-ethylene carbonate (FEC), were investigated (2% weight in EC/DEC) and compared with a reference electrolyte, 1 M LiPF6 (EC/DEC + 2%VC). LiTDI forms a thin SEI with FEC that is uniformly deposited on graphite, which allows high power capability with 93.9% of the specific capacity at 10C (92.3% for 1 M LiPF6 + 2%VC). Excellent results were also obtained for LiTDI with LTO, 91.1% of the specific capacity was recovered at 10C vs. 91.5% for LiPF6. The stability of LiTDI was evaluated in pouch-cells: LFP/LTO (1C-rate) and NMC/LTO (C/4-rate). The results show that the performance of LiTDI is comparable to that of LiPF6, 85.4% of the capacity was recovered after 900 cycles (87.6% for LiPF6) for LFP/LTO, and 85.8% of capacity was obtained after 450 cycles (86.3% for LiPF6) for NMC/LTO.

  6. N-alkyl pyrrolidone ether podands as versatile alkali metal ion chelants.

    Science.gov (United States)

    Perrin, Andrea; Myers, Dominic; Fucke, Katharina; Musa, Osama M; Steed, Jonathan W

    2014-02-28

    This work explores the coordination chemistry of a bis(pyrrolidone) ether ligand. Pyrrolidones are commercially important functional groups because of the high polarity and hence high hydrophilicity and surface affinity. An array of alkali metal ion complexes of a podand bearing two pendant pyrrolidone functionalities, namely 1-{2-[2-(2-oxo-pyrrolid-1-yl)-ethoxy]-ethyl}-pyrrolid-2-one (1) are reported. Reaction of this ligand with sodium hexafluorophosphate gives two discrete species of formulae [Na(1)2]PF6 (3) and [Na3(H2O)2(μ-1)2](PF6)3 (4), and a coordination polymer {[Na3(μ3-1)3(μ2-1)](PF6)3}n (5). The same reaction in methanol gives a 1 : 1 complex, namely [Na2(μ-1)2(MeOH)2](PF6)2 (6). Use of tetraphenyl borate as a less coordinating counter ion gives [Na2(1)2(H2O)4](BPh4)2 (7) and [Na2(1)4](BPh4)2 (8). Two potassium complexes have also been isolated, a monomer [K(1)2]PF6 (9) and a cyclic tetramer [K4(μ4-H2O)2(μ-1)4](PF6)4 (10). The structures illustrate the highly polar nature of the amide carbonyl moiety within bis(pyrrolidone) ethers with longer interactions to the ether oxygen atom. The zinc complex is also reported and {[ZnCl2(μ-1)]}n (11) exhibits bonding only to the carbonyl moieties. The ether oxygen atom is not necessary for Na(+) complexation as exemplified by the structure of the sodium complex of the analogue 1,3-bis(pyrrolid-2-on-1-yl)butane (2). Reaction of compound 1 with lithium salts results in isolation of the protonated ligand. PMID:24336897

  7. A Novel One-Pot Green Synthesis of Dispirooxindolo-pyrrolidines via 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides

    Directory of Open Access Journals (Sweden)

    Abdulrahman I. Almansour

    2015-01-01

    Full Text Available A facile synthesis of dispirooxindolopyrrolidines has been accomplished via a one-pot three component 1,3-dipolar cycloaddition reaction. The reaction of azomethine ylides generated in situ from L-phenylalanine and substituted isatins with a series of unusual (E-2-oxoindolino-3-ylidene acetophenone dipolarophiles in the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]BF4, furnished the cycloadducts in good yields, with the regioisomers 5a–f being obtained with high selectivity. Furthermore, the recyclability of [bmim]BF4, up to five times, was also investigated.

  8. Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

    OpenAIRE

    Erhong Duan; Dishun Zhao; Yanan Wang

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H2O2) = 1:1:0.4, temperature 55 °C, the time 30 min. The ...

  9. Structure and Supersaturation of Highly Concentrated Solutions of Buckyball in 1-Butyl-3-Methylimidazolium Tetrafluoroborate

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Solubilization of fullerenes is of high interest because of their wide usage in both fundamental research and numerous applications. This paper reports molecular dynamics (MD) simulations of saturated and supersaturated solutions of C-60 in 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1IM......][BF4], room-temperature ionic liquid (RTIL). The simulations cover a wide range of temperatures between 280 and 500 K at ambient pressure. Unlike in simpler solvents, C-60 in [C4C1IM][BF4] forms highly supersaturated solutions, whose internal arrangement remains unaltered during nearly a microsecond...

  10. Bioactive Phytochemicals: Bioactivity, Sources, Preparations, and/or Modifications via Silver Tetrafluoroborate Mediation

    Directory of Open Access Journals (Sweden)

    Matthew C. Achilonu

    2015-01-01

    Full Text Available This review provides an overview of the biological activities, natural occurrences, and the silver tetrafluoroborate- (AgBF4- mediated synthesis of proanthocyanidins, glycosides, N-heterocyclic alkaloid analogues (of pyrrole, morphine, quinoline, isoquinoline, and indole, furan analogues, and halocompounds. AgBF4 has been reviewed as an effective reaction promoter, used extensively in the synthesis of relevant biologically active compounds via carbon-carbon and carbon-heteroatom bonds formation. The literatures from 1979 to April 2014 were reviewed.

  11. A novel ionic liquids-based scrubbing process for efficient CO2 capture

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel alkanolamine-based ionic liquid,N-methyl-diethanolammonium tetrafluoroborate ([MDEA][BF4]),was synthesized in our laboratory.The ionic liquid-based composite solution consisting of N-methyl-diethanolamine (MDEA),[MDEA][BF4],piperazine (PZ) and H2O was investigated for CO2 capture.The optimal performance for CO2 capture was found at 45°C,1.50 MPa,probably due to a synergistic action of the reaction and the transport.No apparent corrosion was found on stainless and carbon steel with the above composite solution.This finding is very significant to the promotion of its engineering application.

  12. Bis[N-(2-hydroxybenzyladamantan-1-aminium] fluoride tetrafluoroborate monohydrate

    Directory of Open Access Journals (Sweden)

    Ying-Chun Wang

    2012-02-01

    Full Text Available In the title compound, 2C17H24NO+·BF4−·F−·H2O, the asymmetric unit contains two N-(2-hydroxybenzyladamantan-1-aminium cations, one BF4− anion, one F− anion and one water molecule. Both amine N atoms are protonated. The hydroxy O atoms, amino N atoms and water O atom are involved in intermolecular O—H...O, O—H...F, N—H...O and N—H...F hydrogen bonding.

  13. Preparation of fructone catalyzed by water-soluble Br(φ)nsted acid ionic liquids

    Institute of Scientific and Technical Information of China (English)

    Yuan Yuan Wang; Rong Wang; Liang Chun Wu; Li Yi Dai

    2007-01-01

    Fructone (2-methyl-2-ethylacetoacetate-1,3-dioxolane), a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Br(φ)nsted acid ionic liquids as catalysts for the first time. The used Br(φ)nsted acid ionic liquids include [Hmim]Tfa, [Hmim]Tsa, [Hmim]BF4, [Bmim]HSO4, [Bmim]H2PO4, and [Hmim]BF4 showed the highest catalytic activity for the preparation of fructone. After reaction, the product could be isolated from the reaction system automatically, and the ionic liquid could be directly reused without dehydration.

  14. Biophysical insights into the intercalative interaction of surfactant cobalt(III) complexes of certain diimine ligands bound to yeast tRNA: Effects of hydrophobicity

    Science.gov (United States)

    Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2015-08-01

    The interaction of two surfactant cobalt(III) complexes, cis-[Co(ip)2(DA)2](ClO4)3 1 and cis-[Co(dpq)2(DA)2](ClO4)3 2 where ip = imidazo[4,5-f][1,10]phenanthroline and dpq = dipyrido[3,2-d:2‧-3‧-f]quinoxaline with yeast tRNA have been explored by using electronic absorption, competitive binding, electrochemical studies and viscosity measurements. The results suggest that these complexes can bind to tRNA by intercalation. The presence of hydrophobic diimine ligand and the long aliphatic double chains of these complexes facilitate its intercalative interaction with the hydrophobic interior of the tRNA. The extent of tRNA binding of complex 2 has greater affinity than that of complex containing imidazo[4,5-f][1,10]phenanthroline ligands.

  15. Supramolecular structures constructed from three novel rare earth metal complexes

    Indian Academy of Sciences (India)

    Huaze Dong; Xiaojun Feng; Xia Liu; BiN Zheng; Jianhong Bi; Yan Xue; Shaohua Gou; Yanping Wang

    2015-05-01

    Three rare earth metal supramolecular complexes, {[Tb(2)4](ClO4)3·2H2O(1), [Eu(2)2(H2O)5] (ClO4)3(2) and [Gd(NO3)3(2)2]·2CH3CH2OH(3) ( 2 = 3-Dimethylamino-1-pyridin-2-yl-propenone), have been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. The crystal structure analysis reveals that the coordination numbers of three complexes (1–3) are 8, 9 and 10, respectively. Three complexes assembled into 3D frameworks based on C-H⋯O, O-H⋯O hydrogen bond linkages.

  16. catena-Poly[[[trans-diaquabis(pyridine-κNcobalt(II]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-ylethylidene]hydrazino}benzoato-κ3O:N,N′-[bis(pyridine-κNcobalt(III]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-ylethylidene]hydrazino}benzoato-κ3N,N′:O]perchlorate 3.66-hydrate

    Directory of Open Access Journals (Sweden)

    Igor O. Fritsky

    2008-02-01

    Full Text Available The title compound, {[Co2(C15H14N4O32(C5H5N4(H2O2]ClO4·3.66H2O}n, is a one-dimensional coordination polymer, with both CoII and CoIII centres in its structure. The ligand environment surrounding CoIII is formed by two N,N-chelating pyrazole-containing ligands and two pyridine molecules in axial positions. The high-spin CoII ions, situated at crystallographic centres of inversion, exhibit a distorted octahedral coordination mode. The ClO4− anion is linked to the polymer chain via hydrogen bonds. The chains are connected by hydrogen bonds to produce a three-dimensional structure.

  17. Synthesis, DNA-binding and photocleavage studies of ruthenium(Ⅱ) complexes [Ru(btz)3]2+ and [Ru(btz)(dppz)2]2+

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two new ruthenium(Ⅱ) complexes, [Ru(btz)3](ClO4)2 (1) and [Ru(btz)(dppz)2](ClO4)2 (2) (btz = 4,4′-bithi-azole, dppz = dipyrido[3,2-a:2′,3′-c]phenazine), have been synthesized and characterized by elemental analysis, 1H NMR, ES-MS and X-ray crystallography. The DNA binding behaviors of two complexes have been studied by spectroscopic and viscosity measurements. The results suggest that complex 1 binds to CT-DNA via an electrostatic mode, while complex 2 via an intercalative mode. Under irradiation at 365 nm, both complexes were found to promote the cleavage of plasmid pBR 322 DNA from supercoiled form Ⅰ to nicked form Ⅱ. The mechanism studies reveal that singlet oxygen 1O2 and hydroxyl radical (OH-) play a significant role in the photocleavage process.

  18. Ion Channel Behavior of a Supported Bilayer Lipid Membrane Composed of 5,5-Ditetradecyl-2- (2-trimethyl-ammonioethyl)-l, 3-dioxane Bromide Modified Glassy Carbon Electrode

    Institute of Scientific and Technical Information of China (English)

    龚静鸣; 林祥钦

    2003-01-01

    A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-l,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coatedon an underlying glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), small-angle X-ray diffraction (SAXD) and cyclic voltammetry were used to characterize the s-BLM. Both EIS and SAXD data indicated that the synthetic lipid exists as a well-oriented bilayer in the membrane.The voltammetric study showed that the lipid membrane can open ion channels in the presence of ClO4- stimulant with Ru(bpy)32+ as marker ions and give distinct channel currents.The channels can be dosed and open up again many times by removing or introducing ClO4- anions.

  19. Complexes of rare-earth perchlorates with ditbutyl amides of di, tri and tetraglycolic acids

    OpenAIRE

    Premlatha, C; Soundararajan, S

    1981-01-01

    New complexes of lanthanide perchlorates with di-t-butyl amides of di, tri and tetraglycolic acids have been synthesised. The complexes have the general formula Ln(DiGA)3(ClO4)3; Ln(TriGA)2 (ClO4)3 and Ln(TetGA)2 (C1O4)3, where Ln = La-Yb and Y and DiGA = N,N′, di-t-butyl diglycolamide, TriGA N,N′, di-t-butyl triglycolamide and TetGA = N,N′ di-t-butyl tetraglycolamide, respectively. The complexes have been characterized by analysis, electrolytic conductance, infrared,1H and13C nuclear magneti...

  20. Microwave synthesis of mixed ligand diimine–thiosemicarbazone complexes of ruthenium(ii): biophysical reactivity and cytotoxicity†

    OpenAIRE

    Beckford, Floyd A.; Shaloski, Michael; LeBlanc, Gabriel; Thessing, Jeffrey; Lewis-Alleyne, Lesley C.; Holder, Alvin A.; LI, LIYA; Seeram, Navindra P.

    2009-01-01

    A novel microwave-assisted synthetic method has been used to synthesise a series of mixed ligand ruthenium(ii) compounds containing diimine as well as bidentate thiosemicarbazone ligands. The compounds contain the diimine 1,10-phenanthroline (phen) or 2,2′-bipyridine (bpy) and the thiosemicarbazone is derived from 9-anthraldehyde. Based on elemental analyses and spectroscopic data, the compounds are best formulated as [(phen)2Ru(thiosemicarbazone)](PF6)2 and [(phen)2Ru(thiosemicarbazone)](PF6...

  1. Ionic liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPO

    Institute of Scientific and Technical Information of China (English)

    HU,Ruijun; LEI,Ming; WEI,Hegeng; WANG,Yanguang

    2009-01-01

    In ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate([bmim][PF6])-H2O,a highly chemoselective oxidation of benzylic alcohols in the presence of aliphatic ones to the corresponding hydroxyl benzyl aldehydes and ketones was allowed in high yields using N-chlorosuccinimide(NCS)/NaBr/IL-TEMPO(ionic liquid immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl)as a facile and effective catalytic oxidation system.The medium,[bmiml[PF6],together with the catalyst IL-TEMPO could be easily recycled for ten runs without any influence on the efficacy of the reaction in terms of yield and selectivity of the product.

  2. Synthesis of Two Novel Rhenium(I) Bipyridyl Photosensitive Dyes

    Institute of Scientific and Technical Information of China (English)

    Shi Guo SUN; Xiao Jun PENG; Ming Wen FAN; Yong Qian XU; Lei SHI; Li Cheng SUN

    2004-01-01

    Two novel rhenium(I) 2, 2'-bipyridyl complexes, [(4,4'-di-COOEt-bipy) Re(CO)3 (NCCH3)PF6] and [(4,4'-di-COOEt-bipy) Re (CO)3 (NCS)], a model complex [(4,4'-di- COOEt- bipy) Re (CO)3 (pyridine)PF6], were synthesized.Their ground state electronic spectra and emission spectra were measured in acetonitrile.The MLCT absorption maximum of the complex exhibited a considerable red shift as the ligand changed from pyridine to CNCH3, or SCN.

  3. Trinuclear ruthenium dioxolene complexes based on the bridging ligand hexahydroxytriphenylene: electrochemistry, spectroscopy, and near-infrared electrochromic behaviour associated with a reversible seven-membered redox chain.

    Science.gov (United States)

    Grange, Christopher S; Meijer, Anthony J H M; Ward, Michael D

    2010-01-01

    The trinuclear complexes [{(R2bipy)2Ru}3(mu3-HHTP)](PF6)3 [1(PF6)3, R = H; 2(PF6)3, R = 4-tBu] contain three {Ru(R2bipy)2}2+ fragments connected to the triangular tris-chelating ligand hexahydroxytriphenylene (H6HHTP). This bridging ligand contains three dioxolene-type binding sites, each of which can reversibly convert between dianionic catecholate (cat), monoanionic semiquinone (sq) or neutral quinone (q) redox states. The bridging ligand as a whole can therefore exist in seven different redox states from fully reduced [cat,cat,cat]6- through to fully oxidised, neutral [q,q,q]. Cyclic voltammetry of 1(PF6)3 in MeCN reveals six redox processes of which the three at more positive potentials (the sq/q couples) are reversible but the three at more negative potentials (the sq/cat couples) are irreversible with distorted wave shapes due to the insolubility of the reduced forms of the complex. In contrast, the more soluble complex 2(PF6)3 displays six reversible one-electron redox processes making all components of a seven-membered redox chain accessible. UV/Vis/NIR spectro-electrochemical studies reveal rich spectroscopic behaviour, with--in particular--very intense transitions in the near-IR region in many of the oxidation states associated with Ru(II)-->(dioxolene) MLCT and bridging ligand centred pi-pi* transitions. TDDFT calculations were used to analyse the electronic spectra in all seven oxidation states; the calculated spectra generally show very good agreement with experiment, which has allowed a fairly complete assignment of the low-energy transitions. The strong electrochromism of the complexes in the near-IR region has formed the basis of an optical window in which a thin film of 1(PF6)3 or 2(PF6)3 on a conductive glass surface can be reversibly and rapidly switched between redox states that alternate between strongly absorbing or near-transparent at 1100 nm, with--for 2(PF6)3--the switching being stable and reversible in water over thousands of cycles. PMID

  4. Operando High-Pressure NMR and IR Study of the Hydroformylation of 1-Hexene by 1,1’-Bis-(Diarylphosphino)metallocene-Modified Rhodium(I) Catalyst

    OpenAIRE

    BIANCHINI, C.; W. OBERHAUSER; Orlandini, A; C. Giannelli; P. Frediani

    2005-01-01

    Some rhodium(I) complexes of the general formula [Rh(P-P)(COD)]X were synthesized and characterized by multinuclear NMR spectroscopy (COD ) cyclocta-1,5-diene; P-P ) 1,1'-bis(diphenylphosphino)ferrocene, dppf, X ) BPh4, PF6; P-P ) 1,1'-bis(diphenylphosphino) ruthenocene, dppr, X ) BPh4; P-P ) 1,1'-bis(diphenylphosphino)osmocene, dppo, X ) BPh4, PF6; P-P ) 1,1'-bis(diphenylphosphino)octamethylferrocene, dppomf, X ) BAr'4; P-P ) (1,1'-bis(di(o-isopropylphenyl)phosphino)ferrocene, o-iPr-dppf,...

  5. Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire

    OpenAIRE

    Jun-Jian Shen; Yu-Wu Zhong

    2015-01-01

    The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A “hybridized redox-asymmetry” method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)–6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine...

  6. Monomer, dimer or cyclic helicate? Coordination diversity with hard-soft P,N-donor ligands.

    Science.gov (United States)

    Constable, Edwin C; Hostettler, Nik; Housecroft, Catherine E; Murray, Niamh S; Schönle, Jonas; Soydaner, Umut; Walliser, Roché M; Zampese, Jennifer A

    2013-04-14

    We report the synthesis of copper(I) complexes of three ligands which contain a potential P,N,N,P-metal binding site. Elemental analysis confirms that the bulk products possess a composition of [CuL][PF6] where L = 1, 2 or 3. Electrospray mass spectrometry (ESI MS) provides evidence for speciation in MeCN or MeOH solutions and the formation of both [CuL]+ and [Cu2L2]2+; addition of NaCl to the ESI MS samples aids the observation of dinuclear species as [Cu2L2Cl]+ ions. NMR spectroscopic data for a CD3CN solution of [Cu(1)][PF6] were consistent with a mononuclear species, but more complex multinuclear spectra were observed for the same compound dissolved in CD2Cl2. In the solid state, dimeric species dominate. Crystals grown from CH2Cl2 solutions of [Cu(1)][PF6] are found to be [Cu2(1)2][PF6]2·6CH2Cl2; each Cu+ ion in the centrosymmetric cation is bound in an N,O,P,P-coordination sphere, the N-donor originating from the pyridine ring. In [Cu2(3)2][PF6]2, each bridging ligand in the centrosymmetric [Cu2(3)2]2+ ion acts as a P,N-chelate to each Cu+ ion. Competing with this dimeric assembly is that of a circular helicate in which each ligand 3 bridges adjacent pairs of copper(I) ions in a chiral, hexameric complex; both the Δ,Δ,Δ,Δ,Δ,Δ- and Λ,Λ,Λ,Λ,Λ,Λ-enantiomers are present in the crystal lattice; in [Cu6(3)6]6+, each ligand coordinates as a bis(P,N-chelate). The solution absorption spectra of [Cu(1)][PF6], [Cu(2)][PF6] and [Cu(3)][PF6] are dominated by ligand-based transitions and none of the copper(I) complexes exhibits emissive behaviour in solution.

  7. cis-Difluoridobis(1,10-phenanthroline)chromium(III) perchlorate monohydrate

    DEFF Research Database (Denmark)

    Birk, Torben; Bendix, Jesper; Weihe, Högni

    2008-01-01

    The title complex, [CrF(2)(C(12)H(8)N(2))(2)]ClO(4)·H(2)O, displays a slightly distorted octa-hedral coordination geometry around the central chromium(III) ion. The Cr environment is composed of a cis arrangement of two 1,10-phenanthroline [average Cr(III)-N = 2.0726 (10) Å] and two fluoride...

  8. 4-(2-Azaniumylethylpiperazin-1-ium bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Reisi

    2011-09-01

    Full Text Available In the title compound, C6H17N32+·2ClO4−, the piperazine ring adopts a chair conformation with the ethylammonium fragment occupying an equatorial position. In the crystal, the dications and perchlorate anions are linked through N—H...O hydrogen bonding and weak C—H...O hydrogen bonding into a three-dimensional supramolecular network.

  9. Structure and bonding of some newly synthesized complexes of lanthanide(III) complexes of 4[N-(p-dimetaylaminobenzalidene) amino] antipyrine thiosemicarbazone

    International Nuclear Information System (INIS)

    A series of complexes of the type LnX3.2(DABAAPTS), where Ln = La, Pr, Nd, Sm, Gd, Tb, Dy and Ho, X = ClO4-, or NCS-, DABAAPTS=4[N- (p-dimethylaminobenzalidene) amino] anti pyrine thiosemicarbazone have been synthesized and characterized on the basis of elemental analysis, molecular weight measurements, molar conductance, room temperature magnetic moment, infrared and electronic spectral data. The ligand DABAAPTS behaves as neutral tridentate (N2S) ligand. (author)

  10. Spectroscopic characterization of copper(II) complexes of indoxyl N(4)-methyl thiosemicarbazone

    Science.gov (United States)

    Chandra, Sulekh; Kumar, Umendra

    2004-10-01

    New copper(II) complexes of indoxyl thiosemicarbazone (ITSC) of general composition CuL 2X 2 (where L: ITSC; X: Cl -, NO 3-, ClO 4-, NCS -) have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility measurements and spectral (electronic, IR, EPR, 1H NMR , Mass) studies. Cyclic voltammetry measurements show quasi-reversible Cu 2+/Cu 1+ couple. Various physico-chemical techniques suggest a tetragonal structure for these copper(II) complexes.

  11. Synthesis, Characterization and Biological Activity of Transition Metals with Schiff Base Derived from Adamantaneamine and o-Vanillin

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Five new solid complexes were synthesized about transition metals with Schiff base(L,C18H23NO2) derived from adamantaneamine and o-vanillin, and characterized by elemental analysis, molar conductance, infrared spectra, UV-vis spectra, thermal analysis. Their chemical formula are [ML2](ClO4)2 (M= Mn,Co,Ni,Cu,Zn),and the coordination numbers are four. The antibacterial activity of Schiff base ligand and its complexes was studied.

  12. Bis[N-(8-quinolylpyridine-2-carboxamidato-κ3N,N′,N′′]manganese(III perchlorate monohydrate

    Directory of Open Access Journals (Sweden)

    Yan Pang

    2008-02-01

    Full Text Available The MnIII ion in the title complex, [Mn(C15H10N3O2]ClO4·H2O, is coordinated meridionally by six N atoms from two tridentate N-(8-quinolylpyridine-2-carboxamidate ligands, yielding a distorted octahedral coordination geometry. The two ligands are nearly planar and their mean planes are almost perpendicular, with a dihedral angle of 86.7 (2°.

  13. Microbial perchlorate reduction: A precise laboratory determination of the chlorine isotope fractionation and its possible biochemical basis

    Science.gov (United States)

    Ader, Magali; Chaudhuri, Swades; Coates, John D.; Coleman, Max

    2008-05-01

    Perchlorate-reducing bacteria fractionate chlorine stable isotopes giving a powerful approach to monitor the extent of microbial consumption of perchlorate in contaminated sites undergoing remediation or natural perchlorate containing sites. This study reports the full experimental data and methodology used to re-evaluate the chlorine isotope fractionation of perchlorate reduction in duplicate culture experiments of Azospira suillum strain PS at 37 °C (Δ 37Cl Cl --ClO 4-) previously reported, without a supporting data set by Coleman et al. [Coleman, M.L., Ader, M., Chaudhuri, S., Coates, J.D., 2003. Microbial Isotopic Fractionation of Perchlorate Chlorine. Appl. Environ. Microbiol. 69, 4997-5000] in a reconnaissance study, with the goal of increasing the accuracy and precision of the isotopic fractionation determination. The method fully described here for the first time, allows the determination of a higher precision Δ 37Cl Cl --ClO 4- value, either from accumulated chloride content and isotopic composition or from the residual perchlorate content and isotopic composition. The result sets agree perfectly, within error, giving average Δ 37Cl Cl --ClO 4- = - 14.94 ± 0.15‰. Complementary use of chloride and perchlorate data allowed the identification and rejection of poor quality data by applying mass and isotopic balance checks. This precise Δ 37Cl Cl --ClO 4- value can serve as a reference point for comparison with future in situ or microcosm studies but we also note its similarity to the theoretical equilibrium isotopic fractionation between a hypothetical chlorine species of redox state + 6 and perchlorate at 37 °C and suggest that the first electron transfer during perchlorate reduction may occur at isotopic equilibrium between an enzyme-bound chlorine and perchlorate.

  14. Branched polymeric media: Perchlorate-selective resins from hyperbranched polyethyleneimine

    KAUST Repository

    Chen, Dennis P.

    2012-10-02

    Perchlorate (ClO4 -) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO4 - (10-100 ppb) from contaminated drinking water sources. However, due to the low exchange capacity of perchlorate-selective STY-DVB resins (∼0.5-0.8 eq/L), the overall cost becomes prohibitive when treating groundwater with higher concentration of ClO4 - (e.g., 100-1000 ppb). In this article, we describe a new perchlorate-selective resin with high exchange capacity. This new resin was prepared by alkylation of branched polyethyleneimine (PEI) beads obtained from an inverse suspension polymerization process. Batch and column studies show that our new PEI resin with mixed hexyl/ethyl quaternary ammonium chloride exchange sites can selectively extract trace amounts of ClO4 - from a makeup groundwater (to below detection limit) in the presence of competing ions. In addition, this resin has a strong-base exchange capacity of 1.4 eq/L, which is 1.75-2.33 times larger than those of commercial perchlorate-selective STY-DVB resins. The overall results of our studies suggest that branched PEI beads provide versatile and promising building blocks for the preparation of perchlorate-selective resins with high exchange capacity. © 2012 American Chemical Society.

  15. Different Strategies for Biological Remediation of Perchlorate Contaminated Groundwater

    OpenAIRE

    Wang, Yue

    2012-01-01

    Perchlorate (ClO4-) has gained attention recently due to its interference with thyroid gland function. In infants and unborn children, inadequate thyroid hormone production can cause mental retardation and thyroid tumors. Since new perchlorate standards will be proposed in 2013, and if a stricter standard is imposed, cost effective technologies will be in high demand. The overall objective of this research was to evaluate two perchlorate bioremediation strategies using indigenous soil bact...

  16. Natural chlorate in the environment: Application of a new IC-ESI/MS/MS method with a Cl18O3- internal standard

    Science.gov (United States)

    Rao, Balaji; Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.; Andraski, Brian J.; Eckardt, Frank D.; Jackson, W. Andrew

    2010-01-01

    A new ion chromatography electrospray tandem mass spectrometry (IC-ESI/MS/MS) method has been developed for quantification and confirmation of chlorate (ClO3-) in environmental samples. The method involves the electro-chemical generation of isotopically labeled chlorate internal standard (Cl18O3-) using 18O water (H218O). The standard was added to all samples prior to analysis thereby minimizing the matrix effects that are associated with common ions without the need for expensive sample pretreatments. The method detection limit (MDL) for ClO3- was 2 ng L-1 for a 1 mL volume sample injection. The proposed method was successfully applied to analyze ClO3- in difficult environmental samples including soil and plant leachates. The IC-ESI/MS/MS method described here was also compared to established EPA method 317.0 for ClO3- analysis. Samples collected from a variety of environments previously shown to contain natural perchlorate (ClO 4-) occurrence were analyzed using the proposed method and ClO3- was found to co-occur with ClO4- at concentrations ranging from 500 mg kg-1 in caliche salt deposits from the Atacama Desert in Chile. Relatively low concentrations of ClO3- in some natural groundwater samples (-1) analyzed in this work may indicate lower stability when compared to ClO4- in the subsurface. The high concentrations of ClO3- in caliches and soils (3-6 orders of magnitude greater) as compared to precipitation samples indicate that ClO3-, like ClO4-, may be atmospherically produced and deposited, then concentrated in dry soils, and is possibly a minor component in the biogeochemical cycle of chlorine.

  17. Construction of diverse supramolecular assemblies of dimetal subunits differing in coordinated water molecules via strong hydrogen bonding interactions: Synthesis, crystal structures and spectroscopic properties

    Indian Academy of Sciences (India)

    Sadhika Khullar; Sanjay K Mandal

    2014-09-01

    Three new supramolecular assemblies (constructed through strong hydrogen bonding) of [Co2(bpta)2(adc)(H2O)4](ClO4)2.2H2O (1), [Cu2(bpta)2(fum)(H2O)2](ClO4)2 (2) and [Cu2(bpta)2(tdc)(H2O) (ClO4)](ClO4).3H2O (3), which are synthesised by one pot self-assembly of the metal salt, bpta ligand and the corresponding dicarboxylate under the same reaction conditions, are reported (where adc = acetylene dicarboxylate, fum = fumarate, tdc = 2,5-thiophenedicarboxylate and bpta = N,N'-bis(2-pyridylmethyl)-tertbutylamine). These compounds have varying degrees of coordinatedwater molecules per dimetal subunits (four for 1, two for 2 and one for 3, respectively). Furthermore, the orientation of the coordinated water molecules in 1 and 2, with respect to the mono (carboxylato)-bridged dimetal subunit, is different (cis and trans, respectively). On the other hand, there is a coordinated perchlorate ion in 3 making the two metal centers inequivalent. Unlike 1 and 3, there are no lattice water molecules in 2. This difference in the dimetal subunit in 1-3 and the presence or absence of the lattice water molecules are the keys to forming the diverse supramolecular assemblies. In 1 and 3, the involvement of lattice water molecules in the construction of such assemblies is distinctly different. In case of 2, the formation of supramolecular assembly depends on the coordinated water molecule (trans to each other) and thus a ladder shaped supramolecular assembly is the result. The strength of hydrogen bonding observed in the networks of 1-3 is indicated in the O…O distances (2.596 Å to 3.160 Å) and the OH…O angles 124° to 176°. All are characterised by elemental analysis, FTIR spectroscopy and single crystal X-ray diffraction studies.

  18. Cesium ionophore II as an extraordinarily effective macrocyclic receptor for the barium cation

    Science.gov (United States)

    Makrlík, Emanuel; Böhm, Stanislav; Vaňura, Petr

    2015-02-01

    On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ba2+(aq) + 2ClO4-(aq) + 1(nb) ⇄ 1·Ba2+(nb) + 2ClO4- (nb) occurring in the two-phase water-nitrobenzene system (1 = cesium ionophore II; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (1·Ba2+, 2ClO4-) = 3.4 ± 0.1. Further, the extremely high stability constant of the 1·Ba2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1·Ba2+) = 16.7 ± 0.1. Finally, applying quantum mechanical DFT calculations, the most probable structure of the cationic complex species 1·Ba2+ was derived. In the resulting 1·Ba2+ complex, the "central" cation Ba2+ is bound by four very strong bonding interactions to the respective four oxygen atoms of the parent receptor 1. The interaction energy, E(int), of the considered 1·Ba2+ complex was found to be -1050.4 kJ/mol, confirming also the formation of this significant complex.

  19. Natural Origins, Formation Environmental Mechanisms, and Fate of Perchlorate%环境中高氯酸盐的自然来源、形成机制及其归趋行为

    Institute of Scientific and Technical Information of China (English)

    方齐乐; 陈宝梁

    2012-01-01

    高氯酸盐(Cl04^-)作为新型的环境有毒污染物,其环境污染问题已引起国内外学者的极大关注,但有关ClO4^-的自然来源及形成机制的研究则刚刚起步。ClO4^-的自然来源、在不同环境介质中的背景浓度及迁移转化行为,对制定ClO4^-的环境质量标准和系列安全浓度限值至关重要,但国内相关研究几乎为空白。本文总结了ClO4^-在对流层和平流层气溶胶、大气湿沉降(雨和雪)、地下水、海水、土壤及矿物等环境介质中的背景浓度水平,不同环境介质中涉及样品数为气溶胶3个、雨水1600多个、降雪样品3个、地下水2100多个、海水2个、土壤(矿物)10多个、火星土壤样品1个;重点评述了自然源ClO4^-的前体物质及大气反应形成机制(臭氧氧化、光化学反应和闪电作用),提出ClO2^-/ClO2是大气中ClO4^-自然形成的关键前体物质;归纳了自然源ClO4^-在各环境介质间的迁移转化及归趋行为,最后简单介绍了识别ClO4^-自然来源的同位素示踪技术,并展望相关研究。%Perchlorate (ClO4^-) as an emerging trace pollutant, has caused a great concern about its environmental pollution problems. The natural origin of ClO4^- as well as its formation mechanisms is a new research focus. In order to establish new environmental quality standards and safety concentration limits of ClO4^-, it is quite important to recognize its natural origins, background concentrations, transport and fate in various environmental media, but few researches were reported in China. In this paper, the background concentration levels of ClO4^- in tropospheric and stratospheric aerosol, atmospheric wet deposition (rain and snow), groundwater, seawater, soil and minerals are summarized. The data for ClO4^- concentrations in the aerosol were very limited, such as 0. 5-5 ppt in the stratospheric aerosol, 〈 1.8 ng/m^3 (Japan) and-5.0 ng/m^3 (China) in the tropospheric aerosol. The ClO4^- concentrations in rain were ND--24 400 ng/L for more than 1 600 samples, and 1--18 ng/L in Arctic snow. The ClO4^- concentrations in groundwater were widely inves for China, Germany and India, which were mainly pooled tigated in USA, and recently, some data were reported in 10^-1--10^2 μg/L for more than 2 100 samples. Thereported ClO4^- concentrations in sea water were O. 16----6. 11 μg/L. As a dominant natural origin, the atmospheric reaction mechanisms (i. e. , ozone oxidations, photochemical reactions, and lightning effects) and precursors of ClO4 are highlighted. It is believed that the species of C102-/ C102 is a critical precursor for the formation of natural ClO4^- at the atmosphere. The transport, fate, and biogeochemical cycling of natural ClO4^- in the environments are described in details. The isotope tracer approaches for identification of natural source of ClO4^- are briefly introduced. The research trends and currently existing problems are prospected.

  20. Thermochemical Study of Mixed Ligand Complexes of Rare Earths with Glycine and L-alanine

    Institute of Scientific and Technical Information of China (English)

    QU Jing-nian; LIU Yi; YU Hua-guang; LEI Ke-lin; YAN Cheng-nong; QU Song-sheng

    2004-01-01

    In order to obtain the standard molar enthalpies of formation of Rare-Earth amino acid coordination compounds, precise isothermal solution-reaction calorimetric method was used. The value of ΔrHΘm of two coordination reactions was determined at T = 298.2 K. From the experimental results and other auxiliary values, the standard molar enthalpies of formation of Ln(Gly)5/2(Ala)3/2 (ClO4)3·H2O(s) [Ln = La, Yb] at T = 298.2 K were obtained. The values of them is to be ΔrHΘm [La(Gly)5/2(Ala)3/2(ClO4)3·H2O(s)] =-3545.45 kJ/ mol and ΔrHΘm [Yb(Gly)5/2(Ala)3/2(ClO4)3·H2O(s)]= -3793.81 kJ/mol, respectively.

  1. Thermochemical Study of Lanthanum Complex Crystal with β-Alanine

    Institute of Scientific and Technical Information of China (English)

    陈平初; 屈松生; 詹正坤; 吴新明

    2002-01-01

    Lanthanum complex crystal with β-alanine (1∶3) was synthesized. Through the DTA,TG,chemistry analysis and comparison with literature, it shows that its form is {[La2(β-ala)6* (H2O)4](ClO4)6*H2O}n, and its purity is 98.86%. The dissolution enthalpy of the reactants and products in 2 mol*L-1 HCl solution (298.15K) was measured by using the isoperibol reaction calorimetry. ΔrHm was calculated by a designed thermochemical cycle of the coordination reaction. From the results and other auxiliary quantities, the standard molar enthalpy of formation of [La2(β-ala)6*(H2O)4](ClO4)6*H2O is obtained to be ΔfHm°{[La2(β-ala)6*(H2O)4](ClO4)6*H2O} = - 7062.911 kJ*mol-1.

  2. A study of the effects of solid phase reactions on the thermal degradation and ballistic properties of solid propellants

    Science.gov (United States)

    Schmidt, W. G.

    1974-01-01

    The thermal stability of perchlorate composite propellants was studied at 135 and 170 C. The experimental efforts were concentrated on determining the importance of heterogeneous oxidizer-fuel reactions in the thermal degradation process. The experimental approach used to elucidate the mechanisms by which the oxidizer fuel composites thermally degrade was divided into two parts: (1) keeping the fuel constant and varying the nature of the oxidizers, and (2) holding the oxidizer constant and varying the fuel components. The fuel component primarily utilized in the first phase was polyethylene. Oxidizers included KClO4, KClO3, NH4ClO4 and NH4ClO4 doped with materials such as chlorate, phosphate and arsenate. In the second phase the oxidizer used was primarily NH4ClO4 while the fuels included saturated and unsaturated polybutadiene prepolymers and a series of bonding agents. Techniques employed in the current study include thermogravimetric measurements, differential thermal analysis, infrared, mass spectrometry, electron microscopy, and appropriate wet chemical analysis.

  3. N,N-dimethylbiguanide complexes displaying low cytotoxicity as potential large spectrum antimicrobial agents.

    Science.gov (United States)

    Olar, Rodica; Badea, Mihaela; Marinescu, Dana; Chifiriuc, Mariana-Carmen; Bleotu, Coralia; Grecu, Maria Nicoleta; Iorgulescu, Emilia-Elena; Lazar, Veronica

    2010-07-01

    The new complexes M(DMBG)(2)(ClO(4))(2) (M:Mn, Ni, Cu and Zn; DMBG: N,N-dimethylbiguanide) have been synthesized and characterized by IR, EPR, (1)H NMR, (13)C NMR as well as electronic spectroscopy data. Complex [Ni(DMBG)(2)](ClO(4))(2).2DMF (DMF: N,N-dimethylformamide) crystallizes in the monoclinic P2(1)/c space group while [Cu(DMBG)(2)](ClO(4))(2) adopt monoclinic P21/c space group as X-ray single crystal data indicate. The redox behavior of complexes was investigated by cyclic voltammetry. The metal-free N,N-dimethylbiguanide and complexes exhibit specific anti-infective properties as demonstrated the low MIC values, a large antimicrobial spectrum and also inhibit the ability of Pseudomonas aeruginosa and Staphylococcus aureus strains to colonize the inert surfaces. The complexes exhibit also a low cytotoxicity levels on HeLa cells.

  4. Noninnocence of Indigo: Dehydroindigo Anions as Bridging Electron-Donor Ligands in Diruthenium Complexes.

    Science.gov (United States)

    Mondal, Prasenjit; Chatterjee, Madhumita; Paretzki, Alexa; Beyer, Katharina; Kaim, Wolfgang; Lahiri, Goutam Kumar

    2016-03-21

    Complexes of singly or doubly deprotonated indigo (H2Ind) with one or two [Ru(pap)2](2+) fragments (pap = 2-phenylazopyridine) have been characterized experimentally [molecular structure, voltammetry, electron paramagnetic resonance (EPR), and UV-vis-near-IR spectroelectrochemistry] and by time-dependent density functional theory calculations. The compound [Ru(pap)2(HInd(-))]ClO4 ([1]ClO4) was found to contain an intramolecular NH---O hydrogen bond, whereas [{Ru(pap)2}2(μ-Ind(2-))](ClO4)2 ([2](ClO4)2), isolated as the meso diastereoisomer with near-IR absorptions at 1162 and 991 nm, contains two metals bridged at 6.354 Å distance by the bischelating indigo dianion. The spectroelectrochemical study of multiple reversible reduction and oxidation processes of 2(n) (n = 4+, 3+, 2+, 1+, 0, 1-, 2-, 3-, 4-) reveals the stepwise addition of electrons to the terminal π-accepting pap ligands, whereas the oxidations occur predominantly at the anionic indigo ligand, producing an EPR-identified indigo radical intermediate and revealing the suitability of deprotonated indigo as a σ- and π-donating bischelating bridge. PMID:26931407

  5. Interaction of ternary polypyridine-copper( Ⅱ )- L-α-amino acid complexes with DNA%多吡啶-铜(Ⅱ)-L-α-氨基酸配合物与DNA的作用

    Institute of Scientific and Technical Information of China (English)

    陈佳阳; 任祥祥; 古琴; 乐学义

    2011-01-01

    应用电子吸收光谱、荧光光谱、粘度测定及琼脂糖凝胶电泳法研究了多吡啶-铜(Ⅱ)-L-α-氨基酸型配合物:[Cu(TATP)(L-Val) (H2O)]ClO4·0.5H2O (1)、[Cu(IP)(L-Val)(H2O)]ClO4·1.5H2O (2) 、[Cu(TATP)(L-Tyr)(H2O)]ClO4·H2O(3) 和[Cu(IP)(L-Tyr) (H2O)] ClO4·H2O(4)(TATP=1,4,8,9-四氮三联苯,IP=咪唑并[5,6-f][1,10]邻菲咯啉,L-Val=L-缬氨酸,L- Tyr=L-酪氨酸)与DNA的相互作用.结果表明,作用模式为经典插入作用,且在维生素C存在下配合物对pBR322 DNA具有显著的切割作用,作用大小次序为:配合物1>2>3>4.%The interaction of ternary Cu ( Ⅱ ) complexes [ Cu (TATP) (L-Val) ( H2 0) ] ClO4·0.5 H20(1)、[Cu(IP)(L-Val) (H20) ] ClO4 · 1. 5H20 (2)、[Cu(TATP) (L-Tyr) ( H2 O) ] ClO4 · H20(3) and [ Cu(IP) (L-Tyr) (H2O) ]ClO4 · H20(4)(TATP = 1,4,8,9-tetraaza triphenylen, IP = imidazo-[4,5-f] [ 1,10 ] phenanthroline, L-Val = L-Valinate, L-Tyr = L-Tyrosinate)with DNA have been investigated by electronic absorption spectroscopy, ethidium bromide (EB) fluorescence spectroscopy, and viscosity measurements. The results indicate that the complexes may bind to DNA by intercalative mode and have very strong binding affinities to DNA with the order: complex 1 > 2 > 3 > 4. Moreover, the result of agarose gel electrophoresis shows that the complexes have high cleaving efficiency to pBR322 DNA in the presence of vitamin C.

  6. Application of ionic liquid to polymorphic transformation of anti-viral/HIV drug adefovir dipivoxil.

    Science.gov (United States)

    An, Ji-Hun; Jin, Feng; Kim, Hak Sung; Ryu, Hyung Chul; Kim, Jae Sun; Kim, Hyuk Min; Kiyonga, Alice Nguvoko; Min, Dong Sun; Youn, Wonno; Kim, Ki Hyun; Jung, Kiwon

    2016-05-01

    Ionic liquids (ILs) are defined as salts with a melting point below 100 °C. ILs have received increasing attention as new alternative to organic solvents because of their unique physicochemical properties. Therefore, this study was conducted in the purpose to present the efficacy of ILs as new solvents capable to control the Polymorphic transformation phenomenon. Here, the polymorphic transformation phenomenon of adefovir dipivoxil, an efficient antiviral active pharmaceutical ingredient on human immunodeficiency virus, was investigated. The phase transformation phenomenon from the metastable polymorph, new form (NF) to the stable polymorph, Form-X in 1-allyl-3-ethylimidazolium tetrafluoroborate (AEImBF4) and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BDMImBF4) ILs solutions was observed utilizing the solvent-mediated phase transformation method The thermodynamic factors, AEImBF4/BDMImBF4 solvent composition ratio of 3:7-6:4 and the temperature in range of 25-100 °C, as well as the dynamic factor, the rational speed in range of 300-1000 rpm were parameters studied in this experiment. The thermodynamic and dynamic equations involving nucleation and mass transfer were applied for the quantitative analysis. The result of the present study confirmed the use of ILs as substitute solvent for volatile organic solvents, and demonstrated the efficacy of ILs as potential solvent-media to control the polymorphic transformation. PMID:26908332

  7. C(aryl)-O Bond Formation from Aryl Methanesulfonates via Consecutive Deprotection and SNAr Reactions with Aryl Halides in an Ionic Liquid

    OpenAIRE

    Yang Chen; Hui Xu

    2007-01-01

    An efficient K3PO4-mediated synthesis of unsymmetrical diaryl ethers using the ionic liquid [Bmim]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate) as solvent has been developed. The procedure involves consecutive deprotection of aryl methane-sulfonates and a nucleophilic aromatic substitution (SNAr) with activated aryl halides.

  8. Immobilization of Pd(Ⅱ) Catalysts for Cyclopropanation in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    YANG,Fan(杨帆); ZHANG,Yang-Ming(张仰明); QIU,Wen-Wei(仇文卫); TANG,Jie(汤杰); HE,Ming-Yuan(何鸣元)

    2002-01-01

    Cyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(Ⅱ)in ionic liquid [omim] [BF4] was investigated. Palladium catalysts can be effectively immobilized in ionic liquid.The catalysts PdCl2 and cyclopalladated complex 2 contained in ionic liquid could be recycled for 6 and 7 times, respectively, without losing the efficiency.

  9. Direct Double Electrophilic Fluorination of Allenoic Acids and Tosylamides to Give 1,1-Difluoroallylic Heterocyclic Compounds%Direct Double Electrophilic Fluorination of Allenoic Acids and Tosylamides to Give 1,1-Difluoroallylic Heterocyclic Compounds

    Institute of Scientific and Technical Information of China (English)

    崔海峰; 柴卓; 陆颖鹏; 李鹏; 赵刚; 朱士正

    2011-01-01

    A novel and facile preparation of l,l-difluoroallyl substituted five-membered lactones or pyrrolidines in mod- erate yields through direct double electrophilic fluorination of 4,5-allenoic acids or tosylamides with SelectfluorTM F-TEAD-BF4 is described.

  10. Multicomponent Reaction in Ionic Liquid: A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

    Institute of Scientific and Technical Information of China (English)

    Xin Ying ZHANG; Yan Zhen LI; Xue Sen FAN; Gui Rong QU; Xue Yuan HU; Jian Ji WANG

    2006-01-01

    An efficient and green method for the synthesis of 1, 4-dihydropyridine derivatives mediated in an ionic liquid, [bmim][BF4], through a four-component condensation process of aldehydes, 1, 3-dione, Meldrum's acid and ammonium acetate is disclosed in this paper.

  11. Magnetic interactions in oxide-bridged dichromium(III) complexes. Computational determination of the importance of non-bridging ligands

    DEFF Research Database (Denmark)

    Morsing, Thorbjørn Juul; Sauer, Stephan P. A.; Weihe, Høgni;

    2013-01-01

    The magnetic susceptibility of the dinuclear chromium(III) complex [(CH3CN)5CrOCr(NCCH3)5](BF4)4 · 2 CH3CN has been measured and analyzed. With a fitted value of the triplet energy J = 650 cm-1, the antiferromagnetic coupling is the strongest hitherto determined for an unsupported linear oxide...

  12. Hexaaquacopper(II bis(tetrafluoridoborate–pyrazine 1,4-dioxide (1/3

    Directory of Open Access Journals (Sweden)

    Jan L. Wikaira

    2013-04-01

    Full Text Available The crystal structure of the title compound, [Cu(H2O6](BF42·3C4H4N2O2, comprises discrete [Cu(H2O6]2+ cations and BF4− anions along with three equivalents of pyrazine 1,4-dioxide (pzdo. The hexaaquacopper(II ion and all three pzdo molecules lie about crystallographic inversion centers. The lattice is supported by an extensive hydrogen-bonding network. O—H...O hydrogen bonding between the [Cu(H2O6]2+ and pzdo units creates a pseudo-hexagonal lattice parallel to the bc plane. The BF4− anions lie in the voids of that lattice, held in place by O—H...F hydrogen bonds, and also generate BF4−–pzdo–BF4−–pzdo stacks via short F...N contacts [2.866 (3–3.283 (4 Å].

  13. Synthesis and structural characterization of silver(I), copper(I) coordination polymers and a helicate palladium(II) complex of dipyrrolylmethane-based dipyrazole ligands: the effect of meso substituents on structural formation.

    Science.gov (United States)

    Guchhait, Tapas; Barua, Bhagyasree; Biswas, Aritra; Basak, Biswanath; Mani, Ganesan

    2015-05-21

    A new class of multidentate dipyrrolylmethane based ditopic tecton, 1,9-bis(3,5-dimethylpyrazolylmethyl)dipyrrolylmethane, containing diethyl (L1) or cyclohexylidene (L2) substituents at the meso carbon atom were readily synthesized in 28-45% yields in two different ways starting from dipyrrolylmethanes. A one dimensional coordination polymer structure ([(L2)Ag][BF4])n was obtained when L2 was treated with AgBF4, whereas the analogous reaction between L1 and AgBF4 afforded the dicationic binuclear metallacycle complex [(L1)2Ag2][BF4]2. In addition, yet another coordination polymeric structure [(L1)CuI]n was obtained from the reaction between L1 and CuI. The analogous reaction of L1 with [Pd(PhCN)2Cl2] afforded the binuclear palladium complex [(L1)2Pd2Cl4] having a double-stranded helicate structure. The observed structural differences are attributed to the effects of the substituents present at the meso carbon atom of the ligand, in addition to the nature of the metal centre, coordination number and the preferred geometry.

  14. Fuel cells using ionic liquids as electrolyte and operating at room temperature; Celulas de combustivel utilizando como eletrolito liquidos ionicos e operando a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Botton, Janine Padilha; Souza, Roberto Fernando de; Goncalves, Reinaldo Simoes; Dupont, Jairton [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica], e-mail: janine@iq.ufrgs.br

    2004-07-01

    The room temperature imidazolium based ionic liquids, such as 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) are outstanding electrolytes for fuel cells. A 67% overall cell efficiency is achieve using these liquids as supporting electrolytes for a commercially available alkaline fuel cell (AFC) at room temperature operating with air and hydrogen at atmospheric pressure. (author)

  15. Real-time NMR studies of electrochemical double-layer capacitors.

    Science.gov (United States)

    Wang, Hao; Köster, Thomas K-J; Trease, Nicole M; Ségalini, Julie; Taberna, Pierre-Louis; Simon, Patrice; Gogotsi, Yury; Grey, Clare P

    2011-12-01

    (11)B NMR spectroscopy has been used to investigate the sorption of BF(4)(-) anions on a highly porous, high surface area carbon, and different binding sites have been identified. By implementing in situ NMR approaches, the migration of ions between the electrodes of the supercapacitors and changes in the nature of ion binding to the surface have been observed in real time.

  16. (μ-Formato-κ2O:O′bis[dicarbonyl(η5-cyclopentadienyliron(II] tetrafluoridoborate

    Directory of Open Access Journals (Sweden)

    Cyprian M. M'thiruaine

    2011-09-01

    Full Text Available In the structure of the title compound [Fe2(C5H52(CHO2(CO4]BF4, each FeII atom is coordinated in a pseudo-octahedral three-legged piano-stool fashion. The cyclopentadienyl ligand occupies three fac coordination sites while the two carbonyl ligands and formate O atom occupy the remaining three sites.

  17. 1-Ethyl-3-(2,4,6-trimethylphenylimidazolium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Jin-Tao Guan

    2010-08-01

    Full Text Available The title compound, C14H19N2+·BF4−, was obtained by reaction of 1-ethyl-3-(2,4,6-trimethylphenylimidazolium tetrafluoroborate with sodium tetrafluoroborate. The imidazole ring makes a dihedral angle of 78.92 (13° with the benzene ring.

  18. Organic solvents induce the formation of oil-in-ionic liquid microemulsion aggregations.

    Science.gov (United States)

    Gao, Yanan; Li, Na; Zhang, Shaohua; Zheng, Liqiang; Li, Xinwei; Dong, Bin; Yu, Li

    2009-02-01

    The role of four organic solvents in the formation process of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) based ionic liquid (IL) microemulsions is investigated. The results showed that the addition of Triton X-100 remarkably decreased the conductivity of bmimBF4. The added organic solvents provided a strong apolar environment for the hydrophobic tails of Triton X-100 and caused the surfactant molecules to aggregate into the interfacial film of oil-in-bmimBF4 (O/IL) microemulsions. As a result, the conductivities of the solutions were initially increased because the insulative Triton X-100 molecules were assembled, which corresponded to increasing the concentration of continuous bmimBF4 solutions. The hydrophobic interaction between the dispersed organic solvents and the hydrophobic tails of Triton X-100 may be the driving force for the formation of O/IL microemulsions. The droplets of O/IL microemulsions were successively swollen by organic solvents, and a bicontinuous IL-containing microemulsion was observed by freeze-fracture transmission electron microscopy for the first time. The current study can help in further understanding the ILs-containing microemulsions and thereby improve microemulsion theory. PMID:19138136

  19. Dielectric analysis of micelles and microemulsions formed in a hydrophilic ionic liquid. I. Interaction and percolation.

    Science.gov (United States)

    Lian, Yiwei; Zhao, Kongshuang

    2011-10-01

    Dielectric measurements were carried out on binary mixtures of Triton X-100 (TX-100, a nonionic surfactant with a polyoxyethylene chain) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)], a hydrophilic ionic liquid), and [bmim][BF(4)]/TX-100/cyclohexane microemulsions in a wide frequency range to study the molecular interaction and percolation in these systems. Striking dielectric relaxations were observed, and the dc conductivity data were obtained from the measured total dielectric loss spectra. The interaction between TX-100 and [bmim][BF(4)] is estimated by analyzing the dc conductivity of TX-100/[bmim][BF(4)] solutions in light of the Bruggeman's effective medium approximation, which indicates that spherical micelles are formed when the TX-100 volume fraction is below 48% and the number of cations associated with every TX-100 molecule is eight. For IL-oil microemulsions, both the dependence of dc conductivity and the permittivity (for fixed frequency) on cyclohexane concentration were used to identify the oil-in-IL, bicontinuous, and IL-in-oil microregions. Both the conduction and dielectric relaxation behavior suggest that a static percolation occurs in this hydrophilic IL microemulsion. PMID:21859133

  20. Ionic liquid-in-oil microemulsions.

    Science.gov (United States)

    Eastoe, Julian; Gold, Sarah; Rogers, Sarah E; Paul, Alison; Welton, Tom; Heenan, Richard K; Grillo, Isabelle

    2005-05-25

    Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses of these SANS data are consistent with the formation of ionic liquid-in-oil microemulsion droplets. PMID:15898765