Electrostatic interactions are ubiquitous in ionic liquids and therefore, the electronic environment (i.e. the distribution of electron density) of their constituent ions has a determining influence on their properties and applications. Moreover, the distribution of electron density on atoms is at the core of ionic liquid molecular dynamics simulations. In this work, we demonstrate that changing the composition of ionic liquid mixtures can tune the electronic environment of their constituent ions, both anions and cations. The electronic environment of these ions can be monitored by measuring the characteristic electron binding energies of their constituent atoms by X-ray photoelectron spectroscopy (XPS). The possibility to fine tune, in a controlled way, the electronic environment of specific ions provides an invaluable tool to understand ionic liquid properties and allows the design of ionic liquid mixtures towards specific applications. Here, we demonstrate the power of this tool by tuning the electronic environment of a catalytic centre, and consequently its catalytic activity, by the use of ionic liquid mixtures.

The surface chemistry of a series of four pyrrolidinium based ionic liquids, [CnC1Pyrr][Tf2N] where n = 4–10, is investigated by angle resolved X-ray photoelectron spectroscopy (ARXPS). The importance of sample purity is demonstrated and the stability of the ionic liquids under X-ray irradiation investigated. It is apparent that the surface chemistry and orientation is broadly analogous to that of similar imidazolium-based systems.

Here we report the crystal structures of dicationic ionic liquids (ILs) with both modified cation and anion moieties and discuss the influence of the “supramolecular ionic liquid architecture” that these subtle changes incur. The four dicationic ILs, 1,8-bis(1-methylimidazolium-3-yl)octane bromide (1), 1,8-bis(1,2-dimethylimidazolium-3-yl)octane bromide (2), 1,8-bis(1,2-dimethylimidazolium-3-yl)octane tetrafluoroborate (3) and 1,12-bis(1-methylimidazolium-3-yl)dodecane bromide (4) were prepared using established literature methods. Single crystals of the materials were grown (as solvates for 1·2H2O and 4·1.2(C7H8)) and the solid-state structural arrangements determined by single crystal X-ray diffraction.

Moringa stenopetala seed oil was evaluated as a potential sustainable feedstock for biodiesel production in Ethiopia. Base catalyzed transesterification of M. stenopetala seed oil was carried out with methanol, ethanol and a mixture of methanol and ethanol (1:1 molar ratios) with an alcohol to oil molar ratio of 6:1. The physiochemical characteristics of the esters were assessed to evaluate their suitability for use in standard diesel engines. The study indicated that M. stenopetala seeds yield 45% w/w of oil. The oil contains 78% mono-unsaturated fatty acid and 22% saturated fatty acid. Oleic is the dominant fatty acid, about 76%. When mixtures of alcohols were used, the amount of ethyl ester formed was 30% that of methyl ester. The physicochemical properties of M. stenopetala oil methyl ester and mixture of esters (methyl and ethyl) were found to comply with both the American ASTM D6751 and the European standard EN 14214. Overall, the physicochemical properties of the ester mixture of M. stenopetala oil were better than that of methyl ester. The recommended way to use the oil as a fuel is as a mixture of esters. The study indicates that compared to biodiesel fuels derived from other vegetable oils, M. stenopetala has a number of advantages. Furthermore, the use of M. stenopetala seed oil for the production of biodiesel will not compete with food as neither the seeds nor the oil are used for food in Ethiopia.

Electrostatic interactions are ubiquitous in ionic liquids and therefore, the electronic environment (i.e. the distribution of electron density) of their constituent ions has a determining influence on their properties and applications. Moreover, the distribution of electron density on atoms is at the core of ionic liquid molecular dynamics simulations. In this work, we demonstrate that changing the composition of ionic liquid mixtures can tune the electronic environment of their constituent ions, both anions and cations. The electronic environment of these ions can be monitored by measuring the characteristic electron binding energies of their constituent atoms by X-ray photoelectron spectroscopy (XPS). The possibility to fine tune, in a controlled way, the electronic environment of specific ions provides an invaluable tool to understand ionic liquid properties and allows the design of ionic liquid mixtures towards specific applications. Here, we demonstrate the power of this tool by tuning the electronic environment of a catalytic centre, and consequently its catalytic activity, by the use of ionic liquid mixtures.

The surface chemistry of a series of four pyrrolidinium based ionic liquids, [CnC1Pyrr][Tf2N] where n = 4–10, is investigated by angle resolved X-ray photoelectron spectroscopy (ARXPS). The importance of sample purity is demonstrated and the stability of the ionic liquids under X-ray irradiation investigated. It is apparent that the surface chemistry and orientation is broadly analogous to that of similar imidazolium-based systems.