25. Hu, X.; Tang, J.; Blasig, A.; Shen, Y.; Radosz, M. CO2 permeability, diffusivity and solubility in polyethylene glycol-grafted polyionic membranes and their CO2 selectivity relative to methane and nitrogen. Journal of Membrane Science 2006, 281, 130-138. 26. Hao, L.; Li, P.; Yang, T.; Chung, T.-S. Room temperature ionicliquid/ZIF-8 mixed-
As can be seen by entries 1 and 2 in Table 1, good yields of the tertiary alcohols prepared from the sterically hindered benzophenone even after reuse of the ionicliquid catalyst, shown as yield after second ionicliquid use in Table 1. In order to recycle the ionicliquid after the tertiary alcohol product had been removed, an additional 5 mL of methylene chloride was added, and extraction was completed two additional times, each time combining the organic layers. The organic layers were dried over sodium sulfate, solvent was removed, and then the ionicliquid was dried under vacuum for 22 hours. However, after the third usage, the catalytic activity was significantly diminished and yields of the tertiary alcohols were no longer useful. Yields of the less sterically hindered ynols, entries 3 and 4 in Table 1, were higher, especially for the diol entry 4. Presumably the known ability of oxygen coordination to the magnesium atom of the Grignard reagent helped to facilitate the complexation to the starting material, thus enhancing the already favorable cavitational effect exerted by the ionicliquid.
In 2009, Foroughifar and his colleagues showed that the four component Hantzsch reaction in the solvent-free conditions can be done with sulfamic acid and synthesizes polyhydroquinolines and its derivatives . Rajendran et al (2011) indicated that four component condensation of divergent aromaticaldehydes , cyclic compounds of 1,-3 diketone, β-keto ester,ammoniumacetate and catalystic amount from an ionicliquid Ttrabutylammonium,-2- acrylamide,-2- methyl-propane sulfonate (TBA-AMPS) yields polyhydroquinolines derivatives . However, Redi (2008) developed a more simplified and effective technique for polyhydroquinolines synthesis through the four component reaction of aldehydes, dimedone, ethyl acetoacetate and ammoniumacetate in the presence of p- Toluenesulfonic acid in ethanolic solvent in room temperature . MahboubBasha and colleagues (2012) synthesized 1,-4 dihydropyridines and polyhydroquinolines derivatives through the Hantzsch reaction and using the PEG reagent in solvent-free conditions. The products were directly crystallized with hot methanol. The reaction efficiency with low polyethylene glycol molecular weight was as appropriate as high polyethylene glycol molecular weight . Since Khabazzadeh et al’s  study was about polyhydroquinolines synthesis via heterogeneous and reusable catalyst Cs 2.5 H 0.5 PW 12 O 40 showed high efficiency in short time, so the present paper aims to investigate the theory of the effect
The thesis entitled “Aggregation and Prototropic Behavior within IonicLiquid based Media” is concerned with understanding the behavior of important prototropic probes and cyanine dyes within neat and aqueous ionicliquid (IL) systems. Specifically, prototropism of common prototropic probes and aggregation properties of various cyanine dyes that reveal important properties of neat and aqueous IL media are explored with detailed optical spectroscopic investigations to understand the unique role of these unusual substances. The long term aim is to establish ILs as important and preferred media as far as prototropism and dye aggregation are concerned.
from the aqueous phase. Then, the concentration of the enriched palladium in the sediment phase was determined by FAAS. Some effective parameters that would influence the FAAS signals and the microextraction efficiency, such as concentration of the chelating agent, pH, amount of the ionicliquid, type of disperser solvent and diluting agent, ionic strength, extraction and centrifugation times were investigated and optimized. Under optimum experimental conditions, the detection limit (3 s) and enhancement factor were 3.2 μg/L and 16.2, respectively. The Relative Standard Deviation (RSD) was 1.2% at a concentration of 50 μg/L. The developed method was successfully applied for determining trace amounts of the palladium in the water, soil and vegetable samples.
In the present work, the impact of the addition of lithium salt on viscosity, conductivity, and ionic dissociation in lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-doped bis(trifluoromethanesulfonyl)imide-based ionicliquid ([MPI][TFSI]) electrolyte is evaluated. To evaluate the possibility of using binary [MPI][TFSI] and LiTFSI electrolytes, the solubility of lithium salt in [MPI][TFSI] is examined, homogeneous binary ILs were obtainable over a wide range of salt concentrations ( x Li TFSI = 0 ~ 0.45). The relationship between the ionic conductivity and the viscosity in the neat [MPI][TFSI] and LiTFSI-doped [MPI][TFSI] is analyzed using the Walden rule. The temperature dependence of the diffusion of the individual species (i.e., anion and cation) in an electrolyte formed by doping [MPI][TFSI] with the lithium salt LiTFSI as a function of the LiTFSI mole fraction x were measured using 1 H, 7 Li, or 19 F PGSE-NMR, respectively.
The DEEA is selected in the present work as solvent to solubilize AMPS monomer at room temperature and to prepare polymerizable ionicliquid monomer AMPS-DEA. It is converted to poly(ionicliquid) by radical polymerization the acrylic group of AMPS-DEA monomer. The presence of ethanol group in the chemical structure of DEEA assists its quaternization without coordinating of protonated amine center with the sulfonated anion. This was elucidated from depression the melting point of AMPS from 192 to 42 o C due to formation of PAMPS-DEA.
The ionicliquid consisted of an anion and a cation . Ionic liquids have unique characteristics including very low vapor pressure and wide liquidus range. If an absorption chiller could be operated with an HFC-134a/ionicliquid pair, it could generate cold heat below 0˚C without the need for a flash tower. As the HFC-134a is used as the refrigerant of the mechanical chiller, it is expected to combine with this absorption chiller and mechanical refrigerator.
The experimental and theoretical plots are shown in Fig. 6. It is apparent from this figure that the electrodeposition of Ni at both glassy carbon and Pt substrates follows the three-dimensional instantaneous nucleation/growth process. This behavior is different from that observed for the electrodeposition of Ni in the [EMIm]DCA and Lewis acidic AlCl 3 -EMIC ionicliquid , in which the
approximately 2.95 V (from −1.26 V to 1.69 V) at room temperature. When scanning in the negative direction, both weak and prominent reduction waves were observed at approximately −0.3 and −0.7 V, respectively. On the contrary, when scanning in the reverse direction, two oxidation waves were observed. The current density was determined using the reduction peak current at −0.7 V and the surface area of the working electrode that was immersed into the electrolyte. Additionally, galvanostatic electrodeposition was carried out at 298 K employing an electrolysis time of 22 h and an electrode distance of 23 mm. After electrodeposition, part of the deposits was attached to the substrate while the remaining of the deposits fell into the electrolytic cell via centrifugation until the collection was complete. The above phenomenon was similar to that described in reference . The deposits were analyzed via XRD and EDS, the results of which are presented in Fig. 2. The deposits consisted of high-purity metallic Pd, indicating that the ionicliquid [emim]TA may act as an ideal electrolytic medium for Pd-electrodeposition.
morpholine. Desired product was isolated in 67% yield 5.00 h (Table 1, entry 1). In the solvent toluene the excellent yield obtained (Table 1, entry 2). More polar solvent ethanol was not found to be suitable (Table 1, entry 3) and yield obtained in the less polar solvent dichloromethane was poor. The catalytic loading for the ionicliquid was then determined in the solvent toluene (Table 1, entry 5-7).
The use of ionicliquid analogues as solvents has increased in order to substitute the aqueous solvents in some applications in which the side reactions are undesirable. However these solvents prepared from the mixture in the eutectic proportion of species establishing hydrogen bonds are susceptible of electrochemical reactions. The study of platinum deposition on vitreous carbon in an ionicliquid analogue (2 urea: choline chloride) is presented; the electrochemical study has permitted to interpret the sequence of the metal deposition process and simultaneously to analyze the behavior of the ionicliquid analogue along the process. Reduction reactions of the solvent related both to the electronation of choline and hydrogen formation have been detected. Different substrata have been used in order to test the possibility and the extent of these reactions depending on the nature of material. The results indicate that the feasible electrochemical window of the substrate/solvent is highly dependent of the kind of substrate; the negative limit is tied by the massive hydrogen reaction, reaction enhanced by the electrocatalytic character of the substrate.
A mixture of cinnamaldehydes (1a-g) (7.57 mmol) and tosylhydrazine (2) (7.57 mmol) was dissolved in ionicliquid,1-Butyl-3-methylimidazolium tetrafluoroborate (5 ml) and stirred at room temperature for 30 min.After stirring the reaction mixture for 30 min., the reaction mass was poured on crushed ice. The obtained solid was filtered, washed with water and dried. The crude compound was crystallized using DMF-Ethanol.
As mentioned in Fig. 1, a nucleation process exists in the electroreduction of Pb(II). Chronoamperometry was performed at 373 K to further determine the nucleation mechanism of lead in MIMTfO ionicliquid. It was performed by starting the potential of the working electrode from a value at which no Pb(II) electroreduction occurred to a value where sufficiently negative to initiate the nucleation and growth process. Fig. 3 presents the obtained current-time transient curves. It can be seen that all these transient curves display the typical behavior of a nucleation process [18– 21,24,29,31,33,35,38,39]: after the decay of a sharp electrode double-layer charging current, an increase in the faradaic current was observed due to the nucleation and growth of Pb nuclei. The cathodic current reaches a peak current maximum, i m , as the discrete diffusion zones of individual
17. Gholap AR, Venkatesan K, Thomas D, Lahoti RJ, Srinivasan, K. V.(Ionicliquid promoted novel and efficient one pot synthesis of 3,4-dihydropyrimidin-2-(1H)- ones at ambient temperature under ultrasound irradiation). Green Chem, 2004; 6: 147. (b) Panchgalle SP, Kalkote U R, Nipahadkar P S, Joshi P N, Chavan S P, Chaphekar G M. ( Sn-β molecular sieve catalysed Baeyer–Villiger oxidation in ionicliquid at room temperature). Green Chem, 2004; 6: 308.
bioethanol is good for the environment. But unfortunately most of the chemicals used in the pretreatment processes for bioethanol production are not environmentally benign. In this study we employed the used of ionicliquid which is environmentally friendly in the pretreatment of coca waste, so that the whole process will be “green” (environmentally benign). To determine how effective Ionicliquid pretreatment is, it was compared to the untreated cocoa waste, sulphuric acid pretreatment and sodium hydroxide pretreatment. Ionicliquid pretreatment was found to showed minimal biomass destruction of 30.77% after pretreatment while H 2 SO 4 showed 61.18% and
A suitable host-guest inclusion complex has beenmade with a guest molecule, 1-methyl-3- octylimidazolium chloride ([MOIm]Cl) and a host molecule, α-cyclodextrin in aqueous medium. Formation of the host-guest inclusion complex has been established by Surface tension and conductivity readings while 1 H NMR and ultraviolet spectroscopy readingconfirms1:1 host-guest stoichiometry. These results have implications for the formation of host-guest inclusion complex of studied ionicliquid as guest in aqueous α–cyclodextrin media.
The ionicliquid solutions only showed differences in the FTIR when starch was added when the concentration of water was very low which we attribute to the ability of the acetate to still interact with the starch because there was not enough water to solvate both the starch and the acetate; this solution was slightly more effective in changing the starch structure. In the high water concentration we had no differences in the IR before or after starch was added because there was enough water to completely solvate both the starch and the acetate, preventing any interaction between them. This in turn made the solution less effective in changing the starch structure and the starch transition temperature higher.
ABSTRACT: With increased awareness of global sustainability, there has been growing interest in the preparation of materials from natural, eco-friendly polymers (i.e., biopolymers). Nonetheless, despite their enormous application potential, biopolymers (starch, etc.) have a native semi-crystalline structure with strong hydrogen bonding, and require use of solvents to improve their processibility. However, the dissolution/processing of natural biopolymers such as starch often requires heating and thus significant energy input. Herein, we report an aqueous ionicliquid for fast and facile dissolution of starch, a typical semi-crystalline natural polymer, under ambient conditions. The ionicliquid used is 1-ethyl-3-methylimidazolium acetate ([C 2 mim][OAc]). In particular, it is revealed that 0.15:1 mol/mol [C 2 mim][OAc]:water mixture
However, pure ionic liquids are highly viscous and exhibit relatively low conductivities, which impedes their application in lithium-ion batteries. It is found that the addition of organic dipolar diluents, such as acetonitrile (ACN), ethylene carbonate (EC), diethylene carbonate (DEC) and γ- butyrolactone (γ-BL), to neat ionicliquid is a good way to decrease the viscosity of neat ionic liquids[9-14]. Among them, the aprotic solvent γ-BL has a sufficiently high dielectric constant (39.1 at 25°C), a relatively low viscosity(1.75 mPa·s at 25 °C), a low fusion point (-45 °C) and a high boiling point (204 °C) , the mixed γ-BL and ILs electrolytes can improve both the performance and thermal stability[11,16]. Unfortunately, reversible electrochemical plating and stripping (cycling) of lithium is frequently complicated by the electrochemical instability of the IL moieties at Li + reduction potentials. Most of the systems reported rely on the formation of a solid electrolyte interphase (SEI) to protect the IL from the reactive lithium metal surface. Addition of an appropriate additive，vinylene carbonate (VC)，to IL electrolytes has been shown to facilitate or improve lithium cycling while protecting the IL from reduction at the electrode[8,17-23].