480 research outputs found
Kenneth R. Seddon – A Rock Star of Ionic Liquids
No full textAt the beginning of 2018, the world of science lost one of its most unique and influential people. Professor Kenneth R. Seddon was a pioneering chemist, who dedicated his life to the study and promotion of ionic liquids as a broad chemical platform
Improved synthesis of tadalafil using dimethyl carbonate and ionic liquids
No full textAn improved synthesis of tadalafil, a drug for the treatment of male erectile dysfunction, involves the use of safer solvents and reagents as well as a reduced number of steps
X-ray and molecular dynamics studies of butylammonium butanoate-water binary mixtures
No full textThe nanostructural organisation of mixtures of the ionic liquid (butylammonium butanoate) and water at several mole fractions of water has been investigated using small and wide angle X-ray scattering (S-WAXS) and molecular dynamics (MD) simulations. The presence of a first sharp diffraction peak (FSDP) in the pure ionic liquid has been observed, experimentally and theoretically, suggesting the possibility of segregation of domains of different polarity in the system. With increasing dilution in water, the prepeak is shifted towards smaller Q values, and becomes very weak, while the principal peak moves towards larger Q values. These phenomena suggest the disruption of the hydrogen-bonded network of the ionic liquid, primarily through hydrogen bonding of the anion to water, a conclusion supported by MD simulations
Ionic Liquids further UnCOILed: Critical Expert Overviews
No full textIonic Liquids Further UnCOILed: Critical Expert Overviews continues the discussion of new processes and developments in ionic liquid technology introduced in the first volume. Written by an international group of key academic and industrial chemists, this next book in the series includes eleven overviews of specific areas of ionic liquid chemistry including: Physicochemical properties of ionic liquids. A patent survey. Ionic liquid membrane technology. Engineering simulations. Molecular simulations. The goal of this volume is to provide expert overviews that range from applied to theoretical, synthetic to analytical, and biotechnological to electrochemical, while also offering consistent abbreviations of ionic liquids throughout the text. The value of Ionic Liquids Further UnCOILed: Critical Expert Overviews lies in the authors' expertise and their willingness to share it with the reader. Included in the book is insight into typical problems related to experimental techniques, selection of liquids, and variability of data-all of which were overseen by Professor Ken Seddon, one of the book's editors and a world leader in ionic liquids. This book is a must read for R & D chemists in industrial, governmental, and academic laboratories, and for commercial developers of environmentally sustainable processes. It offers insight and appreciation for the direction in which the field is going, while also highlighting the best published works available, making it equally valuable to new and experienced chemists alike.</p
Structural Properties of 1-Alkyl-3-methylimidazolium Bis{(trifluoromethyl)sulfonyl}amide Ionic Liquids: X-ray Diffraction Data and Molecular Dynamics Simulations
No full textX-ray diffraction data for 1-alkyl-3-methylimidazolium his{(trifluoromethyl)sulfonyl}amides are reported as a function of the length of the alkyl chain on the imidazolium ring. The measured diffraction patterns have been compared with the theoretical patterns calculated (from the geometries obtained) with molecular dynamics simulations. This provides a detailed description (at the atomistic level) of the morphology in the liquid state of these salts, highlighting the role played by the alkyl chain length. An analysis of the behavior of the hydrogen bonds that are formed between the imidazolium acidic protons and the anion is presented
“Sweet” ionic liquid gels: materials for sweetening of fuels
No full textThe search for new materials to be used in desulfurisation (sweetening) of fuels is one of the main topics of current research. In this paper, we explored the possibility of using supramolecular gels obtained from the gelation of ionic liquid binary mixtures. Indeed, some ionic liquids are generally known as efficient extraction phases for desulfurisation of fuels. In rare cases, one of their main drawbacks is their partial solubility in the fuel, leading to contamination. Then, their immobilisation due to the formation of a gelatinous network may be a challenge. Ionic liquid gels were obtained by mixing certain [NTf2]−-based ionic liquids (solvents) with the ones of gluconate-based ionic liquids (gelators). Our gelators are derived from renewable sugars, which possess the marked ability to form hydrogen bonds highly favouring gel formation. In this work, for the first time, ionic liquid gels were used to adsorb typical sulfur compounds omnipresent in fuels. Aromatic sulfur contaminants like thiophene, benzothiophene and dibenzothiophene were selected as model compounds. Our ionogels proved to be efficient adsorption phases, particularly in the removal of benzo- and dibenzothiophenes usually claimed to be refractory compounds for both extraction and oxidative desulfurisation processes. The adsorption efficiency was barely affected by volume, but significantly depended on the fuel concentration
Chiral ionic liquids for catalytic enantioselective sulfide oxidation
No full textA new class of catalytic ionic liquids, containing chiral tungstate(VI) anions, gives enantiomeric excesses up to 96% for sulfide oxidation to sulfoxides.</p
Ionic Liquids Uncoiled: Critical Expert Overviews
No full textIonic Liquids UnCOILed presents decisively important reviews on new processes and recent developments in ionic liquid technology with an emphasis on commercial applications in which ionic liquids are replacing, or may replace, processes currently using conventional solvents. Ranging from applied to theoretical, synthetic to analytical, and biotechnological to electrochemical, the book features eleven chapters written by an international group of key academic and industrial chemists, exercising the judicious evaluation which they are uniquely qualified to do. This book is a must for R and D chemists in industrial, governmental and academic laboratories, and for commercial developers of environmentally-friendly, sustainable processes. </p
Quinine based ionic liquids: A tonic for base instability
No full textSix basic ionic liquids were synthesised from the natural molecule quinine, including one room temperature ionic liquid. The thermal properties were studied and the basicity analysed by Hammett measurements. The properties are discussed in relation to the crystal structure of one of the salts, [C4Qn][NTf2] (2c) and electron density models generated using Spartan. The ionic liquids were shown to catalyse the Knoevenagel condensation of Malononitrile and Benzaldehyde.</p
- …
