N-butyl-pyridinium tetrafluoroborate as a highly efficient ionic liquid for removal of dibenzothiophene from organic solutions

In this research,1-butyl-pyridinium tetrafluoroborate([C4Py][BF4]-)was prepared by ion exchange method and was characterized by1H-NM R,13C-NM R,and FT-IR techniques.The synthesized ionic liquid w as used for removal of dibenzothiophene as a typical organosulfur pollutant from organic medium.The effect of different parameters on the extraction efficiency w as studied and optimized.At the optimized conditions,97.68%of dibenzothiophene w as extracted from 1 000 mg/L n-hexane solution.The extraction efficiency obtained in this w ork w as higher than the previous reported values.The desulfurization reaction w as kinetically follow ed the second order mechanism.The ionic liquid w as reusable and after four regeneration cycles 97%of its original extraction efficiency w as retained.

Applications of ionic liquids in electrodeposition of rare earths

The electrodeposition and electrochemical behaviors of rare earths in different ionic liquids are summarized. It is demonstrated that most of the rare earths can be electrodeposited in ionic liquids except cerium. Anion of ionic liquids appears to play a significant role in determining the electrochemical windows, and then deciding whether the corresponding ionic liquids can be used for rare earths electrodeposition. The electrochemical behaviors of the reduction process in ionic liquids are similar to those in high-temperature molten salts. The reduction of RE(III) to RE(II) has different reversibility, but the reaction of rare earths to their zerovalent state is irreversible.

Periodicity and map for discovery of new ionic liquids

There is virtually no limit in the number of ionic liquids. How to select proper ones or discover new ones with desirable properties in such a large pool of ionic liquids? It has become a bottleneck in the researches and applications of ionic liquids. Mendeleev’s periodic law states that the properties of the elements vary periodically. Whether the similar regularity exists among ionic or mo-lecular fragments of compounds is an interesting topic. In this work, we attempted to establish a pe-riodicity and draw a “map” of ionic liquids for providing definite guidance to discover, design, and se-lect the proper ionic liquids rather than trial-and-error. If a complete regularity of the system of ionic liquids can be finally established in the future, we are near an epoch in understanding the existing differences and the reasons for the similarity of the ions or molecular fragments.

Understanding cellulose dissolution： effect of the cation and anion structure of ionic liquids on the solubility of cellulose

The effect of ionic liquids(ILs) on the solubility of cellulose was investigated by changing their anions and cations. The structural variation included 11 kinds of cations in combination with 4 kinds of anions. The interaction between the IL and cellobiose, the repeating unit of cellulose, was clarified through nuclear magnetic resonance(NMR) spectroscopy. The reason for different dissolving capabilities of various ILs was revealed. The hydrogen bonding interaction between the IL and hydroxyl was the major force for cellulose dissolution. Both the anion and cation in the IL formed hydrogen bonds with cellulose. Anions associated with hydrogen atoms of hydroxyls, and cations favored the formation of hydrogen bonds with oxygen atoms of hydroxyls by utilizing activated protons in imidazolium ring. Weakening of either the hydrogen bonding interaction between the anion and cellulose, or that between the cation and cellulose, or both, decreases the capability of ILs to dissolve cellulose.