Christian Schreiner

Alkali Metal Oligoether Carboxylates—A New Class of Ionic Liquids

On the way to greener ILs: The combination of a short oligoether carboxylate (CH3O-(CH2CH2O)3-CH2COO-) with small alkali metal cations leads to the formation of a new class of ionic liqs. that exhibit high thermal and electrochem. stability as well as low cytotoxicity.

Temperature Dependent Impedance Analysis of Binary Ionic Liquid Electrolytes for Dye-Sensitized Solar Cells

At platinum electrodes kinetics of the I - /I - 3 electrode reaction were studied at two potential electrolyte systems for dye-sensitized solar cells (DSSCs) based on binary ionic liquid (IL) blends, i.e., 1-ethyl-3-methylimidazolium dicyanamide ([EMIM] [N(CN) 2 ])/1-methyl-3-propylimidazolium iodide ([PMIM]I) and l-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM] [BF 4 ])/[PMIM]I, respectively. The charge transfer resistances of the electrode reaction were determined via impedance spectroscopy for electrolyte blends at a mixing ratio of ILs of 9 mol % [PMIM]I (for [EMIM][N(CN)2]/[PMIM]I) and 10 mol % [PMIM]I (for [EMIM][BF 4 ]/[PMIM]I) up to 100 mol % [PMIM]I. In addition, the influence of iodine concentration on the electrode reaction was investigated for both electrolyte systems. The measurements were taken in a temperature range of 25 to 60°C to analyze the electrolyte properties in view of thermal stress of the DSSC for later practical application. Furthermore, exchange current densities were determined: the expected Arrhenius behavior was observed. Activation energies were obtained by fitting linearized Arrhenius plots.

Chloride‐Free Method to Synthesise New Ionic Liquids with Mixed Borate Anions

Chloride avoided! A new chloride-free method to synthesise ionic liquids (ILs) with mixed borate anions, starting from tetrafluoroborate compounds, has been developed and a number of examples including some new ILs are presented (see scheme; [CAT](+) = cation). It is widely applicable and allows access to mixed borates with various types of ligands in a straightforward manner.