Joanna Feder-Kubis

Structure and thermal properties of salicylate-based-protic ionic liquids as new heat storage media. COSMO-RS structure characterization and modeling of heat capacities

During this research, we present a study on the thermal properties, such as the melting, cold crystallization, and glass transition temperatures as well as heat capacities from 293.15 K to 323.15 K of nine in-house synthesized protic ionic liquids based on the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate ([H-Im-C1OC(n)][Sal]) with n = 3-11. The 3D structures, surface charge distributions and COSMO volumes of all investigated ions are obtained by combining DFT calculations and the COSMO-RS methodology. The heat capacity data sets as a function of temperature of the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate are then predicted using the methodology originally proposed in the case of ionic liquids by Ge et al. 3-(Alkoxymethyl)-1H-imidazol-3-ium salicylate based ionic liquids present specific heat capacities higher in many cases than other ionic liquids that make them suitable as heat storage media and in heat transfer processes. It was found experimentally that the heat capacity increases linearly with increasing alkyl chain length of the alkoxymethyl group of 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate as was expected and predicted using the Ge et al. method with an overall relative absolute deviation close to 3.2% for temperatures up to 323.15 K.

The phytotoxicity of ionic liquids from natural pool of (-)-menthol with tetrafluoroborate anion.

Over the last several decades, ionic liquids have become a promising alternative to conventional organic solvents. Initially, ionic liquids were described as “environmentally friendly” substances. However, the results of numerous studies proved that the effects of these compounds on individual ecosystems might be adverse. The presented paper discusses the effect of ionic salts containing natural chiral substituent: (1R,2S,5R)-(−)-menthol in cation and a tetrafluoroborate anion of a general formula of [Cn-Im-Men][BF4] of implementation into the soil on the growth of spring barley and common radish in their early development stages. The obtained results showed that the greatest phytotoxicity was exhibited by ionic liquids containing substituents with the smallest possible number of carbon atoms. The further increase in the length of the chain did not increase the toxicity of these salts for terrestrial plants. Moreover, a compound with a substituent having a chain length of 11 carbon atoms was found to be non-toxic to common radish. The experiment under discussion showed also the effect of these tetrafluoroborates, used in the form of spray, on the development of common sorrel, gallant soldier and white goosefoot. The tests carried out also showed that the most toxic were the compounds with 1 and 3 carbon atoms. The phytotoxicity of tetrafluoroborates was positively correlated with the concentration of these compounds in the soil and was dependent on the genetic features of the genres and varieties of plants used in the experiment.

Symmetrical Imidazolium Chloride Based on (−)-Menthol: Synthesis, Characterization, and Theoretical Model of the Reaction

New symmetrical imidazolium chloride from a natural chiral pool of (1R,2S,5R)-(-)-menthol can be efficiently prepared by two different methods. The first method involves a specific type of Menschutkin reaction using novel 1-(1R,2S,5R)-(-)-menthoxymethylimidazole as amine, chloromethyl (1R,2S,5R)-(-)-menthyl ether as quaternization agent, and hexane as solvent. In the second method, imidazole, chloromethyl (1R,2S,5R)-(-)-menthyl ether, and DMF are used. To understand this specific type of the reaction, quantum chemical calculations at the DFT level have been used. The preparation and characterization of 1,3-bis[(1R,2S,5R)-(-)-menthoxymethyl]imidazolium chloride are reported.

Physical Properties of Chiral Ionic Liquids Based on (–)-Menthol

Abstract In this study, the significant effect of the cationic structures of chiral ionic liquids on their physical properties has been shown. An analysis has been made for the structure of ammonium, alkylimidazolium, alkoxymethylimidazolium, and pyridinium bis(trifluoromethanesulfonyl)imides. Comparison of physical properties of different liquid salts was made for the density, viscosity, thermal degradation, and glass transition temperature. The lowest density and viscosity are characteristic of the 1-[(1R,2S,5R)-(–)-menthoxymethyl]-3-alkylimidazolium bis(trifluoromethanesulfonyl)imides and the trialkyl[(1R,2S,5R)-(–)-menthoxymethyl]ammonium bis(trifluoromethanesulfonyl)imides. Moreover, the largest liquid range characterized the 3-alkoxymethyl-1-(1R,2S,5R)-(–)-menthoxymethylmidazolium bis(trifluoromethanesulfonyl)imides. GRAPHICAL ABSTRACT

Chiral protic imidazolium salts with a (−)-menthol fragment in the cation: synthesis, properties and use in the Diels–Alder reaction

New chiral protic imidazolium salts containing a (1R,2S,5R)-(−)-menthol substituent in the cation and four different anions (chloride, hexafluorophosphate, trifluoromethanesulfonate and bis(trifluoromethylsulfonyl)imide) were efficiently prepared and extensively characterized. Detailed NMR analysis was performed, and a comparison of the chemical shifts of the protons and carbons of the imidazolium cation as a function of the combined anion was discussed. The specific rotation, solubility in commonly used solvents, thermal properties including phase transition temperatures, and thermal stability were also determined. Three of the synthesized tertiary salts (Cl, PF6 or OTf anion) were crystalline solids; 1-H-3-[(1R,2S,5R)-(−)-menthoxymethyl]-imidazolium bis(trifluoromethylsulfonyl)imide, (−)[H-Ment-Im][NTf2] was a liquid at room temperature. The chiral protic salts were used in a Diels–Alder reaction as a test reaction, and the results were compared with those from aprotic chiral ionic liquids having the same chiral substituent in the cation (1R,2S,5R)-(−)-menthol with a bis(trifluoromethylsulfonyl)imide anion. Both protic and aprotic chiral salts, used in a Diels–Alder reaction, were pure (−)-enantiomers, which was determined by NMR with Δ-TRISPHAT tetrabutylammonium salt as a chiral shift reagent. Protic salts offered distinctly higher endo/exo ratios than aprotic ones, but an enantiomeric excess was not obtained. The stereoselectivity reached the same high level even after the fourth recycle of (−)[H-Ment-Im][NTf2] in the reaction of ethyl-vinyl ketone with cyclopentadiene at temperature of −35 °C.

The Effect of Ionic Liquids With (–)-Menthol Derivative Containing a Chloride Anion to Weed

Abstract Weeds constitute a huge group of undesirable plants, widespread throughout the world. They represent a big problem for most farmers, who implement different methods to fight against them. Thanks to their wide occurrence, weeds however, can be an excellent indicator of the quality of soil and the whole environment where they are present. In this paper, we present the impact of four alkylimidazolium chlorides with a natural terpene component introduced into the soil: (1R,2S,5R)-(–)-menthol and alkyl substituents containing 1, 4, 9 or 12 carbon atoms, on the growth and development of selected weed species. Compounds with the highest phytotoxic activity towards gallant soldier, white goosefoot and common sorrel were chlorides with methyl and butyl substituents, while compounds with nonyl and dodecyl substituents demonstrated a weak effect on these weeds. Phytotoxicity of the salts tested was largely dependent on the applied concentration of the compound and the genetic make-up of plant species used in the experiment. This was reflected in the inhibition of plants’ length and their roots, as well as changes in the content of dry matter and photosynthetic pigments.

Design and synthesis of new chiral ionic liquids as potential antielectrostatic agents

A research on ionic liquids, across many varied applications, is strong and still growing area of interest. New chiral imidazolium-based ionic liquids containing (1R,2S,5R)-(–)-menthol substituent, having symmetrical structure of the salts, have been synthesized and characterized. Monocyclic terpen alcohol: (1R,2S,5R)-(–)-menthol, obtained from a variety of mint (Menthae L.), was used as a substrate in two different reactions to obtain 1,3-bis[(1R,2S,5R)-(–)-menthoxymethyl]imidazolium chloride [1], which is a prototype of chiral ionic liquids. After that, metathesis of this symmetrical imidazolium chloride with various organic and inorganic salts in menthol or water/menthol solution was carried out. The ion exchange reaction goes smoothly, with the satisfactory exceed (from 94 to 99%). Discussed symmetrical salts belong to Chiral Ionic Liquids (CILs) where the chirality resides in the cation and is associated with the presence of optical active (1R,2S,5R)-(–)-menthol. Obtained symmetrical salts are hydrophobic, and airand moisture-stable under ambient conditions. Moreover, they are non-volatile and non-flammable. Some of the 1,3-bis[(1R,2S,5R)-(–)-menthoxymethyl]imidazolium salts [i.e.: chloride, bis(trifluoromethanesulfonyl) imide, acesulfame, saccharinate] possess excellent antielectrostatic properties and their ability to drain the surface charge is similar to these of a known antistatic agent (Catanac 609: American Cyanamin Co.).