A novel method for in situ measurement of solubility via impedance scanning quartz crystal microbalance studies.

We introduce here a novel in situ measurement method for solubility of solids in various liquids. Without any calibration the saturation point can be obtained in a relative manner. We exemplified the new method at four systems including water, organic carbonates and an ionic liquid as the solvents and various salts as dissolved solids.

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.

Overcoming kinetic limitations of electron injection in the dye solar cell via coadsorption and FRET.

A new, extremely simple concept for the use of energy transfer as a means to the enhancement of light absorption and current generation in the dye solar cell (DSC) is presented. This model study is based upon a carboxy-functionalized 4-aminonaphthalimide dye (carboxy-fluorol) as donor, and (NBu4)2[Ru(dcbpy)2(NCS)2] (N719) as acceptor chromophores. A set of three different devices is assembled containing either exclusively carboxy-fluorol or N719, or a mixture of both. This set of transparent devices is characterized via IV-measurements under AM1.5G and monochromatic illumination and their light-harvesting and external quantum efficiencies (LHE and EQE, respectively) are determined as well. It is shown that the device containing only the donor chromophore has a marginal power conversion efficiency, thus indicating that carboxy-fluorol is a poor sensitizer for the DSC. Cyclovoltametric measurements show that the poor sensitization ability arises from the kinetic inhibition of electron injection into the TiO2 conduction band. Comparing the spectral properties of the DSCs assembled presently, however, demonstrates that light absorbed by carboxy-fluorol is almost quantitatively contributing to the photocurrent if N719 is present as an additional sensitizer. In this case, N719 acts as a catalyst for the sensitization of TiO2 by carboxy-fluorol in addition to being a photosensitizer. Evaluation of the maximum output power under blue illumination shows that the introduction of an energy-donor moiety via coadsorption, leads to a significant increase in the monochromatic maximum output power. This result demonstrates that energy transfer between coadsorbed chromophores could be useful for the generation of current in dye-sensitized solar cells.

Trialkylsulfonium dicyanamides--a new family of ionic liquids with very low viscosities.

Trialkylsulfonium dicyanamides show surprisingly low viscosities down to -20 degrees C and are therefore highly interesting liquid materials for separation processes and electrolyte applications at low temperatures.