- Effect of imidazolium ionic liquids on the hydrolytic activity of lipase
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The effect of 1-alkyl-3-methylimidazolium ionic liquids (ILs) on the hydrolysis activityof Candida rugosa lipase (CRL) toward triacylglycerol was investigated. The critical micelle concentrations (CMC) of ILs with Br -, Cl-, and [BF4]- anions and the solubility of ILs with [PF6]- anions were determined in phosphate buffer. Results suggested that the content of the ILs, not kosmotropicity, highly influenced the effects of anions and cations of ILs on CRL activity. As the length of alkyl chain of the cation [CnMIM] + increased, lower IL content was required to achieve high enzyme activity. Once the concentrations of the ILs with Br-, Cl -, and [BF4]- anions exceeded the CMC value, enzyme activity was suppressed. The positive promotion effect of anions on enzyme activity was in the order of Br- Cl- [BF 4]- [PF6]-. The effect of ionic liquid on enzyme activity was highly dependent on the pH and temperature of the system, with the optimum pH being 7.000. Under optimal conditions of pH 7.000, 30 °C, and 47.6 mmol/L of [C8MIM]Br, the highest relative activity of CRL (1734%) was achieved, with a specific activity of 54.4 U/mg protein.
- Li, Na,Du, Weiyan,Huang, Zhuonan,Zhao, Wei,Wang, Shoujiang
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- Properties modification by eutectic formation in mixtures of ionic liquids
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The composition and temperature of three eutectic mixtures were determined at atmospheric pressure in systems resulting from the combination of pairs of ionic liquids where each ionic liquid was constituted by only one type of cation and only one type of anion. In addition, the three pairs investigated had a common ion (either the cation or the anion), thus totalising just three different ions in the resulting mixture. All three eutectic mixtures had a temperature near the ambient one, meaning a decrease of up to ca. 50 K with regard to the melting temperature of the parent ionic liquids. A characterisation of physical properties (density, viscosity, and surface tension) of the eutectic mixtures was carried out, and compared as appropriate with those of the parent compounds.
- Stolarska, Olga,Soto, Ana,Rodríguez, Héctor,Smiglak, Marcin
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- Ionic liquid co-lyophilized enzyme for biocatalysis in organic solvent: Remarkably enhanced activity and enantioselectivity
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The room temperature solid-phase ionic liquid (RTSPIL) co-lyophilized enzyme exhibited markedly enhanced activity in organic solvent. The enzyme co-lyophilized with a dodecyl-imidazolium salt was 660-fold more active compared to its RTSPIL-free counterpart. The activity enhancement by RTSPILs was mainly attributable to the reduced particle sizes and improved dispersion of enzymes suspended in organic solvent. Also, the RTSPIL co-lyophilized enzyme displayed significantly enhanced enantioselectivity. Its enantioselectivity was 2.5-fold higher than that of its RTSPIL-free counterpart.
- Lee, Jae Kwan,Kim, Mahn-Joo
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- Bidentate cation-anion coordination in the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate supported by vibrational spectra and NBO, AIM and SQMFF calculations
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Experimental attenuated total reflectance (ATR) and Raman spectra for the synthesized ionic liquid 1-Ethyl-3-methylimidazolium hexafluorophosphate [EMIM+][PF6 ?] have been combined with the functional hybrid B3LYP and the 6-31G? and 6-311++G?? basis sets in order to evaluate the coordination mode of [PF6 ?] anion and determine the its structural, electronic, topological and vibrational properties. The scaled quantum mechanical force fields (SQMFF) methodology allowed us to obtain a set of scaled force constants fitting the observed wavenumbers because, so far, they have not reported. Experimental ATR and Raman spectra for the ionic liquid [EMIM+][PF6 ?] in the solid phase are consistent with the corresponding predicted by using both levels of theory. Here, complete vibrational assignments of 72 normal modes of vibration expected for ionic liquid were performed by using B3LYP/6-311++G?? level and considering that the [PF6 ?] anion adopts a bidentate coordination mode. Atomic Merz-Kollman (MK) charges and bond orders studies have revealed a distorted octahedral symmetry of anion in the ionic liquid and have suggested bidentate coordination of anion by two C–H?F hydrogen bonds, as experimentally was also proposed. Natural bond orbital (NBO) and atoms in molecules (AIM) calculations support the high stability of ionic liquid and its high dipole moment value. Frontier orbitals for the three species show that the [PF6 ?] anion increases the reactivity of ionic liquid. Here, we determine that the B3LYP/6-311++G?? molecular force field for the ionic liquid [EMIM+][PF6 ?] with the bidentate coordination mode adopted by [PF6 ?] anion is well represented, as also was supported by the scaled force constants calculated for both C–H?F hydrogen bonds.
- Assenine, Mohammed Amin,Brandán, Silvia Antonia,Bresson, Serge,Haddad, Boumediene,Paolone, Annalisa,Villemin, Didier
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- A Superstrong and Reversible Ionic Crystal-Based Adhesive Inspired by Ice Adhesion
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In this study, we developed a superstrong and reversible adhesive, which can possess a high bonding strength in the “adhesive” state and detach with the application of heating. An ionic crystal (IC) gel, in which an IC was immobilized within a soft-polymer matrix, were synthesized via in situ photo-crosslinking of a precursor solution composed of N, N-dimethyl acrylamide (DMAA) and a melted IC. The obtained IC gel is homogenous and transparent at melt point. When cooled to the phase transition temperature of the IC, the gel turns into the adhesive with the adhesion strength of 5.82 MPa (on glasses), due to the excellent wetting of melted gel and a thin layer of crystalline IC with high cohesive strength formed on the substrates. The synergistic effects between IC, polymer networks and substrates were investigated by solid state 1H NMR and molecular dynamics simulation. Such an adhesive layer is reversable and can be detached by heating and subsequent re-adhesion via cooling. This study proposed the new design of removable adhesives, which can be used in dynamic and complex environments.
- Liu, Lili,Liu, Ziyang,Ren, Yongyuan,Zou, Xiuyang,Peng, Wansu,Li, Weizheng,Wu, Yiqing,Zheng, Sijie,Wang, Xiaoliang,Yan, Feng
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- Lewis Acid Catalyzed Synthesis of Cyanidophosphates
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Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF6-n(CN)n]- (n=1-4) were synthesized by a very mild Lewis-acid-catalyzed synthetic protocol and fully characterized. All [PF6-n(CN)n]- (n=1-4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)5]- but not the [P(CN)6]- anion. The best results with respect to purity, yield, and low cost were obtained when the F-/CN- substitution reactions were carried out in ionic liquids. Cyanido(fluorido)phosphates: Salts containing [PF6-n(CN)n]- (n=1-4) ions were isolated on a preparative scale by utilizing Lewis acids (LA) catalysts under mild conditions (see equation). The best results with respect to purity, yield, and low cost were obtained when the F-/CN- substitution reactions were carried out in ionic liquids.
- Bl?sing, Kevin,Ellinger, Stefan,Harloff, J?rg,Schulz, Axel,Sievert, Katharina,T?schler, Christoph,Villinger, Alexander,Zurt?schler, Cornelia
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supporting information
p. 4175 - 4188
(2016/03/16)
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- A green and novel procedure for the preparation of ionic liquid
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A green and novel procedure is described for the preparation of a series of ionic liquid containing alkylimidazolium-based or N-alkylpyridinium-based cations and hexafluorophosphate-based or tetrafluoroborate-based anions in one-pot solvent-free conditions to give excellent yields with shortened time.
- Fang, Dong,Cheng, Jian,Gong, Kai,Shi, Qun-Rong,Zhou, Xin-Li,Liu, Zu-Liang
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p. 108 - 111
(2008/09/21)
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- Organic salt conditioner, organic salt-containing composition, and uses thereof
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The present invention relates to the use of, and a composition containing, at least one non-polymeric organic salt with a melting point of less than 60° C. These organic salts may be imidazolium, pyrazolium, pyridinium, pyrimidinium or tetraalkylphosphonium salts. The inventinon composition may be used for washing (cleaning) and/or conditioning keratin materials, and especially the hair.
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- Process for preparing ambient temperature ionic liquids
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A process for preparing an ionic liquid or salt, preferably in which the cation comprises an N-alkylated base and the anion is a carboxylate, formed by reaction between an organic base and an alkylating agent, wherein the alkylating agent is a fluorinated ester or an alkyl sulfonate, is described. Suitable organic bases include imizadoles, substituted imidazoles, pyridines and substituted pyridines. The so-formed products can be subsequently transformed into different ionic liquids or salts by metathesis.
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- Halogenide-free preparation of ionic fluids
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Preparation of ionic liquids (I) involves alkylating an amine, phosphine, imidazole, pyridine, triazole or pyrazole corresponding to the cation of (I) with a sulfate diester (II), then replacing the sulfate anion by the anion of (I). Preparation of ionic liquids of formula (I) involves alkylating the amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation A, with a sulfate diester of formula (II), then replacing the sulfate anion R4SO4 or R5SO4 by the anion Yn-. (An).(Yn-) (I) R4SO2R5 (II) n = 1 or 2; Yn- = BF4, BCl4, PF6, SbF6, AsF6, AlCl4, ZnCl3, CuCl2, SO4, CO3, R'COO, R'SO3 or (R'SO2)2N; R' = 1-12C linear, branched or cyclic alkyl, 5-18C aryl, (5-18C) aryl-(1-6C) alkyl or (1-6C) alkyl-(5-18C) aryl (all optionally halo-substituted); A = NR1R2R3R or PR1R2R3R; or 1-(R)-3-(R1)-imidazolium, (R1)-substituted 1-(R)-pyridinium, 1-(R)-2-(R1)-pyrazolium or 1-(R)-1,3,5-triazolium (all optionally ring-substituted by one or more of 1-6C alkyl, 1-6C alkoxy, 1-6C aminoalkyl, 5-12C aryl or (5-12C) aryl-(1-6C) alkyl); R1-R3 = H; 1-20C linear, branched or cyclic alkyl; Het or Het-(1-6C) alkyl; or Ar or Ar-(1-6C) alkyl; R, R4, R5 = 1-24C linear, branched or cyclic alkyl; Het-(1-6C) alkyl; or Ar'-(1-6C) alkyl; Het = heteroaryl containing 3-8C and at least one of N, O and S (optionally substituted by one or more of 1-6C alkyl and halo); Ar = 5-12C aryl (optionally substituted by one or more of 1-6C alkyl and halo); and Ar' = 5-24C aryl (optionally substituted by one or more of 1-6C alkyl and halo).
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- Single step preparation of ionic fluids
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Preparation of ionic liquids (I) involves alkylating an amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation of (I), with a halide (II) then replacing the sulfate anion by the anion of (I), the process is carried out without isolation of the intermediate. In the preparation of ionic liquids of formula (I) involves alkylating the amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation A with a halide of formula (II) then replacing the sulfate anion X by the anion Yn-, the process is carried out without isolation of the intermediate. (A)n.(Yn-) (I) RX (II) n = 1 or 2; Yn- = BF4, BCl4, PF6, SbF6, AsF6, AlCl4, ZnCl3, CuCl2, SO4, CO3, R'COO, R'SO3 or (R'SO2)2N; R' = 1-12C linear, branched or cyclic alkyl, 5-18C aryl, (5-18C) aryl-(1-6C) alkyl or (1-6C) alkyl-(5-18C) aryl (all optionally halo-substituted); A = NR1R2R3R or PR1R2R3R; or 1-(R)-3-(R1)-imidazolium, (R1)-substituted 1-(R)-pyridinium, 1-(R)-2-(R1)-pyrazolium or 1-(R)-1,3,5-triazolium (all optionally ring-substituted by one or more of 1-6C alkyl, 1-6C alkoxy, 1-6C aminoalkyl, 5-12C aryl or (5-12C) aryl-(1-6C) alkyl); R1-R3 = H; 1-20C linear, branched or cyclic alkyl; Het or Het-(1-6C) alkyl; or Ar or Ar-(1-6C) alkyl; R = 1-20C linear, branched or cyclic alkyl; Het-(1-6C) alkyl; or Ar-(1-6C) alkyl; Het = heteroaryl containing 3-8C and at least one of N, O and S (optionally substituted by one or more of 1-6C alkyl and halo); Ar = 5-12C aryl (optionally substituted by one or more of 1-6C alkyl and halo); and X = halogen.
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