- Ion transport in a class of imidazole-based liquid/solid protic ionics
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A class of protic ionic-compounds were prepared by Bronsted acid-base reaction of imidazole or benzimidazole with one of the following acids: trifluoromethanesulfonic, nonafluorobutanesulfonic, para-toluenesulfonic and trifluoroacetic. Except those based on trifluoroacetic acid, all prepared compounds are thermally stable up to at least 270°C. They are solid up to temperatures between 134 and 220°C, depending on their constituent acid and base. A simple physico-mathematical model of ion motion in the lattice was developed and implemented to correctly interpret frequency-dependent electrical response of these materials, particularly in the solid state, and investigate their ion-conducting behavior as a function of temperature. These ionic compounds display sensible ionic conductivity up to ca. 5 × 10 -4 and 5 × 10-2 S cm-1 in the solid and molten state, respectively, under fully anhydrous conditions. The presence of absorbed water, after brief exposure to an ambient atmosphere, enhances conduction properties remarkably. Conductivity values up to 10-3 and 10-1 S cm-1 were registered, respectively, in the solid and molten state, after short exposure to (humid) ambient air. It is argued how absorbed water molecules may remove protons from (ImH)+ or (BImH)+ groups, thereby enabling a chain mechanism of proton-hopping through non-protonated Im or BIm sites. It is discussed how these results and methods may inspire designing protic ionic-materials at the solid-state, with enhanced proton conduction even under fully-anhydrous conditions.
- Tricoli, Vincenzo,Orsini, Gabriele,Anselmi, Martina
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- Self-assembled structure and dynamics of imidazolium-based protic salts in water solution
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Protic ionic liquids containing cations with long alkyl chains can form self-assembled micelles, vesicles, microemulsions, and lyotropic liquid crystal structures in water, acid water or tetrahydrofuran, etc. As a result of this unique property, they are regarded as a novel category of amphiphiles, and are gaining importance in the field of colloid and interface chemistry. The critical micelle concentration (CMC) of protic salts, e.g., alkyl-ammonium nitrates in water, was found to increase with decreasing chain length. It is generally believed that a long alkyl chain length is essential for the formation of self-assembled structures. So far, no self-assembled structure has been reported for protic ionic liquids with an alkyl chain length of n a methyl group (n = 1) attached to the cation in water solution, determined through a detailed analysis of NMR spectra and pulsed-field gradient NMR data. We demonstrate that these imidazolium cations with no or a short alkyl chain (n = 1) can form a self-assembled clustering structure in water solution, which has a strong influence on the diffusion behavior of imidazolium molecular ions. It is speculated that this self-assembled structure is likely to be present in other similar solutions of ionic liquids with short alkyl chains.
- Zhu, Haijin,Vijayaraghavan,Macfarlane, Douglas R.,Forsyth, Maria
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p. 2691 - 2696
(2019/02/07)
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- Method for chemical synthesis of oligonucleotides
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The present invention provides a practical method capable of chemically synthesizing a 100-mer or more long-chain oligonucleotide easily and reliably and a novel compound used in said method. The present invention relates to a method for chemical synthesis of an oligonucleotide by the phosphoroamidite method, which comprises preparing a base moiety-unprotected nucleoside phosphoroamidite from a base moiety-unprotected nucleoside by use of an imidazole trifluoromethanesulfonate represented by the following chemical formula, and coupling said base moiety-unprotected nucleotide phosphoroamidite in a predetermined order to chemically synthesize an oligonucleotide consisting of a specific nucleotide sequence, as well as to an imidazole trifluoromethanesulfonate represented by the chemical formula. STR1
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- Method for chemical synthesis of oligonucleotides
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The present invention provides a practical method capable of chemically synthesizing a 100-mer or more long-chain oligonucleotide easily and reliably and a novel compound used in said method. The present invention relates to a method for chemical synthesis of an oligonucleotide by the phosphoroamidite method, which comprises preparing a base moiety-unprotected nucleoside phosphoroamidite from a base moiety-unprotected nucleoside by use of an imidazole trifluoromethanesulfonate represented by the following chemical formula, and coupling said base moiety-unprotected nucleotide phosphoroamidite in a predetermined order to chemically synthesize an oligonucleotide consisting of a specific nucleotide sequence, as well as to an imidazole trifluoromethanesulfonate represented by the chemical formula.
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- Imidazole compounds and their use as transglutaminase inhibitors
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Imidazole compounds including imidazoles and imidazolium salts, and their use as transglutaminase inhibitors are disclosed.
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- Anhydrides of Phosphorus and Sulfur Acids, 2. Mixed Anhydrides of Phosphoric, Phosphonic, and Phosphinic Acids with Sulfonic Acids and Sulfuric Monoimidazolide. New Methods of Synthesis, Novel Structures, Phosphorylating Properties
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New applications of methods leading to anhydrides RR'P(O)OSO2R'' (1) are described: a) Reaction of acids RR'P(O)OH (2) with sulfonic imidazolides. b) Reaction of phosphorus imidazolides 4 with sulfonic acids and sulfonic anhydrides.New methods of synthesis of anhydrides 1 have been developed. c) Reaction of phosphorus acid silyl esters RR'P(O)OSiMe3 (9) with methanesulfonic and trifluoromethanesulfonic anhydrides. d) Reaction of bis(trimethylsilyl) tert-butylphosphonate (10) with methanesulfonic acid leading to tBuP(O)(OSO2Me)2 (11). e) Reaction of stannyl phosphate (EtO)2P(O)OSnMe3 (15) with methanesulfonic anhydride. f) Reaction of phosphorus acid silyl esters 9 with trimethylsilyl trifluoromethanesulfonate.All methods result in high yields and can be adapted to a variety of anhydrides 1 derived from phosphoric, phosphonic, and phosphinic acids on the one hand and methanesulfonic, trifluoromethanesulfonic acids and sulfuric monoimidazolide on the other.Phosphonium intermediates have been demonstrated by low temperature FT 31P NMR spectroscopy for reaction b) and c).The anhydrides 1 are readily converted into imidazolides 4 by the reaction with N-(trimethylsilyl)imidazole which proceeds via two distinct phosphonium intermediates.With neutral and weakly basic nucleophiles, the anhydrides 1 behave as phosphorylating agents.
- Dabkowski, Wojciech,Michalski, Jan,Skrzypczynski, Zbigniew
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p. 1809 - 1824
(2007/10/02)
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