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In this work the complete valence-band structure of the molybdenum dichalcogenides MoS 2 , MoSe 2 , and ␣-MoTe 2 is presented and discussed in comparison. The valence bands have been studied using both angleresolved photoelectron spectroscopy ͑ARPES͒ with synchrotron radiation, as well as ab initio band-structure calculations. The ARPES measurements have been carried out in the constant-final-state ͑CFS͒ mode. The results of the calculations show in general very good agreement with the experimentally determined valenceband structures allowing for a clear identification of the observed features. The dispersion of the valence bands as a function of the perpendicular component k ជ Ќ of the wave vector reveals a decreasing three-dimensional character from MoS 2 to ␣-MoTe 2 which is attributed to an increasing interlayer distance in the three compounds. The effect of this k ជ Ќ dispersion on the determination of the exact dispersion of the individual states as a function of k ជ ʈ is discussed. By performing ARPES in the CFS mode the k ជ ʈ component for off-normal emission spectra can be determined. The corresponding k ជ Ќ value is obtained from the symmetry of the spectra along the ⌫A, KH, and M L lines, respectively.

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To enlarge the restricted knowledge about the hazard potentials of ionic liquids to men and the environment we have concentrated on systematically analysing the effects of 7 head groups, 10 side chains (mainly containing functional groups) and 4 anions on cytotoxicity. For our investigations, we used the promyelotic leukemia rat cell line IPC-81 as test system, with the reduction of the WST-1 dye as an indicator of cell viability. Our results show that most of the tested 100 ionic liquids generally exhibit a low cytotoxicity compared to previously investigated ionic liquids in consequence of their polar ether, hydroxyl and nitrile functional groups within the side chains. Those functional groups hamper cellular uptake by membrane diffusion and reduce lipophilicity based interactions with the cell membrane.In general, a low influence of the head group and a clear anion effect of the [(CF 3 SO 2 ) 2 N] 2 anion could be observed. Furthermore, we could confirm the general dependency between ionic liquid cation lipophilicity and cytotoxicity using a HPLC derived lipophilicity parameter. For one head group and for one side chain, deviations were obtained concerning this general dependency. This can be interpreted as a first hint for a more specific mode of action for these structural elements.

Abstract. We present two -270 kyr paleo-sea surface temperature (SST) records from the Equatorial Divergence and the South Equatorial Current derived from Mg/Ca ratios in the planktic foraminifer Globigerinoides sacculifer. The present study suggests that the magnesium signature of G. sacculifer provides a seasonal SST estimate from the upper -50 m of the water column generated during upwelling in austral low-latitude fall/winter. Common to both down-core records is a glacial-interglacial amplitude of-3ø-3.5øC for the last climatic changes and lower Holocene and glacial oxygen isotope stage 2 temperatures compared with interglacial stage 5.5 and glacial stage 6 temperatures, respectively. The comparison to published SST estimates from alkenones, oxygen isotopes, and foraminiferal transfer function from the same core material pinpoints discrepancies and conformities between methods.

The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities.