- Versatile Method for the Simultaneous Synthesis of Two Ionic Liquids, Otherwise Difficult to Obtain, with High Atom Economy
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A new synthetic approach and full spectral (NMR, IR, MS) and ion chromatographic characterization (IC) of nitrogen-based ionic liquids bearing allyl- or ethyl- substituent and triflate, tosylate, methyl sulfate or methanesulfonate anion has been presented. On a sample of 16 new ionic liquids, the versatility of the anion exchange method has been proven. In the metathesis reactions that have been carried out, the halide anion was exchanged in ionic liquid with an alkyl sulfonate based anion using alkylating agents. The results obtained using ion chromatographic analysis on the newly synthesized compounds have been discussed. Also, the utilization of a gaseous methyl halide by-product, obtained in the metathesis reaction and otherwise difficult to synthesize, has been presented. This approach ensured high atom economy of the overall process, which makes the proposed methodology sustainable and eco-friendly.
- Szpecht, Andrea,Zajac, Adrian,Zielinski, Dawid,Maciejewski, Hieronim,Smiglak, Marcin
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p. 972 - 983
(2019/08/06)
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- A spectroscopic and molecular dynamics simulation approach towards the stabilizing effect of ammonium-based ionic liquids on bovine serum albumin
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In this article, we have explored the impact of ammonium-based ionic liquids (ILs) on the thermal unfolding/refolding of bovine serum albumin (BSA) in aqueous solutions using thermal circular dichroism (CD) spectroscopy and molecular dynamic simulation studies. In attempting to find ILs that can stabilize BSA at higher temperatures, we found good results with ammonium-based ILs. Our results show that the hydrophobicity of the IL is very crucial in the refolding phenomenon. A more hydrophobic IL, triethylhexylammonium bromide, shows better refolding of thermally denatured BSA and the stabilization is found to be dependent on the concentration of the IL. Moreover, fluorescence measurements (synchronous, life time, 8-anilino-1-naphthalenesulfonic acid (ANS)) were used to decipher the conformational changes of the protein in the IL medium. The spectroscopic studies suggest that the native state of BSA is not altered in the IL medium, rather a compact structure of BSA is established which is further supported by the molecular dynamics simulation analysis. In addition, the esterase-like activity of BSA was studied in the IL medium and the possible binding sites were investigated using a molecular docking program. We hope that the present study is successful in interpreting the possible mechanism of interaction between BSA and ILs as well as the stabilizing/destabilizing effect of ILs on BSA.
- Satish, Lakkoji,Millan, Sabera,Bera, Krishnendu,Mohapatra, Sujata,Sahoo, Harekrushna
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p. 10712 - 10722
(2017/10/03)
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- Method of producing oxyborate Tetracyanobicyclo (by machine translation)
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing a tetracyanoborate compound (VI). SOLUTION: A boron compound (for example, boron trichloride) and an ammonium derivative having a halogenide ion as a counter anion are mixed in xylol; then, a trialkylsilyl cyanide is added and reacted; the reaction system is subjected to a treatment with hydrogen peroxide, and an extraction treatment with butyl acetate; and butyl acetate is distilled out to obtain a tetracyanoborate compound represented by formula (VI) wherein [Kt]m+ is an ammonium cation; and m=1. In the formula, [Kt]m+ denotes an organic cation or an inorganic cation; and m denotes an integer of 1 to 3. COPYRIGHT: (C)2012,JPO&INPIT
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Paragraph 0088
(2016/12/26)
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- NMR study of the complex formation between tert-butyl hydroperoxide and tetraalkylammonium bromides
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The interaction between tert-butyl hydroperoxide and tetraalkylammonium bromides was studied by NMR spectroscopy in acetonitrile-d 3 at 298 K. The complex formation between the hydroperoxide molecule and corresponding quaternary ammonium salt w
- Turovskij, Nikolaj A.,Berestneva, Yulia V.,Raksha, Elena V.,Zubritskij, Mikhail Yu.,Grebenyuk, Serhiy A.
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p. 1443 - 1448
(2014/11/27)
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- Physicochemical characterization of MFm--based ammonium ionic liquids
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A series of ammonium-based ionic liquids (ILs), which share a homologous series of cations (CH3CH2)3N+(C nH2n+1) with n = 2, 4, 6, 8 and the anions with either BF4-, PF6-, or SbF6 -, was synthesized. Their structures were confirmed by 1H and 13C NMR, ESI-MS, and elemental analysis. Meanwhile, the content of impurity (e.g., water and bromide ions) was also determined using Karl Fischer titrator and ion chromatography. The thermal properties of the ILs were determined by TGA and DSC. Five of the investigated ILs have been shown to have a low melting point (2222]BF4, N,N,N,N-tetraethylammonium hexafluorophosphate, [N2222]PF6, N,N,N- triethylhexylammonium tetrafluoroborate, [N2226]BF4, N,N,N-triethyloctylammonium hexafluorophosphate, [N2228]PF 6 and N,N,N-triethyloctylammonium hexafluoroantimonate, [N 2228]SbF6. Densities, refractive indices, and miscibility of these 12 ILs were well studied systematically. Moreover, from the analysis of the structure-property relationship, the role of the alkyl chain length of the cation on these physical properties of the ILs has been assessed, and the influence of the nature of the anions on these experimental data of the ILs has been discussed. The studies may provide valuable contributions for the design and study of ILs.
- Li, Haifang,Zhao, Guoying,Liu, Fangfang,Zhang, Suojiang
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p. 1505 - 1515
(2013/07/26)
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- Effects of charge separation, effective concentration, and aggregate formation on the phase transfer catalyzed alkylation of phenol
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The factors that influence the rate of alkylation of phenol under phase transfer catalysis (PTC) have been investigated in detail. Six linear, symmetrical tetraalkylammonium cations, Me4N+, Et 4N+, (n-Pr)4N+, (n-Bu) 4N+, (n-Hex)4N+, and (n-Oct) 4N+, were examined to compare the effects of cationic radius and lipophilicity on the rate of alkylation. Tetraalkylammonium phenoxide·phenol salts were prepared, and their intrinsic reactivity was determined from initial alkylation rates with n-butyl bromide in homogeneous solution. The catalytic activity of the same tetraalkylammonium phenoxides was determined under PTC conditions (under an extraction mechanism) employing quaternary ammonium bromide catalysts. In homogeneous solution the range in reactivity was small (6.8-fold) for Me4N+ to (n-Oct) 4N+. In contrast, under PTC conditions a larger range in reactivity was observed (663-fold). The effective concentration of the tetraalkylammonium phenoxides in the organic phase was identified as the primary factor influencing catalyst activity. Additionally, titration of active phenoxide in the organic phase confirmed the presence of both phenol and potassium phenoxide aggregates with (n-Bu)4N+, (n-Hex)4N+, and (n-Oct)4N+, each with a unique aggregate stoichiometry. The aggregate stoichiometry did not affect the PTC initial alkylation rates.
- Denmark, Scott E.,Weintraub, Robert C.,Gould, Nathan D.
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supporting information; experimental part
p. 13415 - 13429
(2012/09/25)
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- Robust antimicrobial compounds and polymers derived from natural resin acids
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We report novel robust resin acid-derived antimicrobial agents that exhibit excellent antimicrobial activities against a broad spectrum of bacteria (6 Gram-positive and 7 Gram-negative) with selective lysis of microbial membranes over mammalian membranes. Our results indicate that hydrophobicity and unique structures of resin acids can be determining factors in dictating the antimicrobial activity.
- Wang, Jifu,Chen, Yung Pin,Yao, Kejian,Wilbon, Perry A.,Zhang, Wujie,Ren, Lixia,Zhou, Juhua,Nagarkatti, Mitzi,Wang, Chunpeng,Chu, Fuxiang,He, Xiaoming,Decho, Alan W.,Tang, Chuanbing
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supporting information; experimental part
p. 916 - 918
(2012/02/04)
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- Synthesis and in vitro enzyme hydrolysis of trioxadiaza- and tetraoxadiaza-crown ether-based complexing agents with disposable ester pendant arms
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New disposable ester derivatives of the complexing agents N,N′-bis(carboxymethyl)piperazine, -homopiperazine, -1,7-diaza-15-crown-5 and -1,10-diaza-18-crown-6 were synthesized with a variety of synthetic methods and fully characterized. Hydrolytic properties of the pendant arms were studied under different pH conditions as well as in the presence and absence of porcine liver esterase enzyme and approximate hydrolysis half lives were determined by 1H NMR technique. In vitro studies on pig liver cell homogenates and living thin chicken liver slices proved that the selected double ester 4b can penetrate liver tissues spontaneously, liberate the free complexing agent N,N′-bis(carboxymethyl)-18-ane-N2O4 (ODDA) inside the cells and are potentially capable of removing lead and other toxic metal ions from the liver. Georg Thieme Verlag Stuttgart.
- Ivanyi, Timea,Lazar, Istvan
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p. 3555 - 3564
(2007/10/03)
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- CATALYSIS BY AMINE SALTS OF SOME AROMATIC NUCLEOPHILIC SUBSTITUTION REACTIONS
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The reaction of 1-chloro-2,4-dinitrobenzene with aniline in acetonitrile is catalysed by R4NY where Y is Cl, Br, I, or toluene-p-sulphonate, but not by 1,4-diazabicyclooctane (DABCO).When the nucleophile is changed to n-butylamine or morpholine, addition of tetraethylammonium chloride has only a small effect; the reactions of all three nucleophiles are not catalysed by tetraethylammonium perchlorate.The reaction of 1-fluoro-2,4-dinitrobenzene with aniline is strongly catalysed by tetraethylammonium chloride, to a lesser extent by the bromide and toluene-p-sulphonate and also by trimethylamine hydrochloride, but not by tetraethylammonium perchlorate.The reactions of morpholine with 1-fluoro-2,4-dinitrobenzene and piperidine with 2,4-dinitrophenyl phenyl ether are not catalysed by amine salts.The results are consistent with the formation and stabilisation of the intermediate formed in aromatic nucleophilic substitution reactions by the anions of the salts, when the nucleophile is aniline
- Hirst, Jack,Onyido, Ikenna
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p. 711 - 716
(2007/10/02)
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