- IONIC LIQUIDS, THE METHOD FOR PREPARING THE SAME AND METHOD FOR REMOVING ACETYLENES FROM OLEFIN MIXTURES USING THE IONIC LIQUIDS
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There are provided an ionic liquid having ether group(s) in which a copper(I) compound is included, a method for preparing the same, and a method for removing traces amounts of acetylene-based hydrocarbon compounds included in olefin by absorption or extraction using the same. When the disclosed solution is used, oxidation of Cu(I) to Cu(II) is prevented since CuX is stabilized by the ionic liquid. Thus, selective removal efficiency of acetylenic compounds is improved greatly while the removal performance is retained for a long period of time. Further, since the solution according to the present disclosure is applicable as an extractant as well as an absorbent, the associated operation is simple and apparatus cost can be decreased.
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Page/Page column 4
(2012/04/11)
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- Sulfonyl transfer from imidazoles
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The rate constants for the non-catalyzed bimolecular substitution of 1-tosylimidazole, 1, 1-tosyl-3-methylimidazolium, 2, and 1-tosyl-2,3-dimethylimidazolium, 3, chlorides by primary aliphatic amines (5 n Nu=0.5, 0.5 and 0.6 respectively.Despite large variations in the reactivity, 6 powers of ten from 1 to 2, and in the leaving group pK's, 7 units from 2 to 1, the nucleophile effect is found to be nearly constant.The nucleofuge effect is also independent of the nucleophile; apparent βL-coefficients of approximately - 0.9 are observed whatever the amine.These data correspond to rate-limiting transition states where there is small but significant bonding of the sulfonyl with the entering amines and with the leaving imidazoles.These results strongly suggest a concerted single-step displacement mechanism; however, a stepwise mechanism involving a very unstable and very short-lived pentahedric intermediate cannot be strictly ruled out.These findings are compared with those on other acyl transfers.
- Monjoint, P.,Ruasse, M. F.
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p. 356 - 360
(2007/10/02)
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- KINETICS OF THE PHENOLYSIS OF ACID CHLORIDES IN A PROTON-INERT MEDIUM. NUCLEOPHILIC CATALYSIS BY TERTIARY AMINES
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The kinetics of the reactions of ArOH with acid chlorides (AcX), catalyzed by tertiary amines (B), were studied by UV spectroscopy in methylene chloride (25 deg C): 1) Benzoyl chloride with β-naphthol (B = N-methylimidazole); 2) benzenesulfonyl chloride with p-phenylazophenol (B = 4-dimethylaminopyridine) with the following concentrations 0 >/= 0 >> 0.A nucleophilic mechanism of catalysis with rapid and equilibrium accumulation of the intermediate products, i.e., N-benzoyl-3-methylaminoimidazolium (Ia) and N-phenylsulfonyl-4-dimethylaminopyridinium (Ib) chlorides, is realized in the case of reactions (1) and (2).In the slow stage the intermediates (I) transfer the acyl group not to the free ArOH but to the hydrogen-bonded complexes of ArOH with (I) and with the amines (B), the formation constants of which were determined independently.One of the above-mentioned paths represents the "intramolecular" transfer of the acyl group in the associate ArOH...(I), whereas the second represents bimolecular attack by the intermediate (I) on the complex ArOH...B.In view of the complexing effects an equation was derived for the phenolysis rate which makes it possible to calculate the rate constants for transfer of the acyl group.Thus, the motivating force of the reactions (1) and (2) in the proton-inert medium is proton transfer even in the initial state, while nucleophilic catalysis is realized exclusively in conjunction with general-base assistance on the part of the anion of the intermediate (I) ("intramolecular" catalysis) or on the part of the free base B (intermolecular catalysis) to the transfer of the proton from ArOH in the rate-controlling stage.
- Simanenko, Yu. S.,Savelova, V. A.,Litvinenko, L. M.,Belousova, I. A.,Dadali, V. A.,Zubareva, T. M.
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p. 123 - 131
(2007/10/02)
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- MECHANISM OF THE REACTION OF ACETYL HALIDES WITH AROMATIC AMINES IN THE PRESENCE OF N-SUBSTITUTED IMIDAZOLES
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The effect of the structure of aromatic amines and the nature of the leaving group in N-acetylimidazolium chlorides in reactions leading to the formation of amides in methylene chloride at 25 deg C was investigated.The possibility of stabilization of the transition state of the bimolecular reaction on account of general-base assistance on the part of the anion of the salt was demonstrated by analysis of the sensitivity of the bimolecular reaction of the acylimidazolium salt with aromatic amines to the nature of attacking and leaving groups.At the same time the mechanism of the trimolecular reaction of the salt with the arylamine does not fit into the scheme of the general-base catalysis by the anion and is interpreted by the inclusion of aggregates of N-acetylimidazolium halides in the transition state of trimolecular reaction.
- Lapshin, S. A.,Dadali, V. A.,Litvinenko, L. M.,Simanenko, Yu. S.
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p. 1730 - 1735
(2007/10/02)
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