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Abstract. Measurements of the submicron fraction of the atmospheric aerosol in the marine boundary layer were performed from January to March 2007 (Southern Hemisphere summer) onboard the French research vessel Marion Dufresne in the Southern Atlantic and Indian Ocean (20 • S-60 • S, 70 • W-60 • E). We used an Aerodyne HighResolution-Time-of-Flight AMS to characterize the chemical composition and to measure species-resolved size distributions of non-refractory aerosol components in the submicron range.Within the "standard" AMS compounds (ammonium, chloride, nitrate, sulfate, organics) "sulfate" is the dominant species in the marine boundary layer with concentrations ranging between 50 ng m −3 and 3 µg m −3 . Furthermore, what is seen as "sulfate" by the AMS is likely comprised mostly of sulfuric acid.Another sulfur containing species that is produced in marine environments is methanesulfonic acid (MSA). There have been previously measurements of MSA using an Aerodyne AMS. However, due to the use of an instrument equipped with a quadrupole detector with unit mass resolution it was not possible to physically separate MSA from other contributions to the same m/z. In order to identify MSA within the HR-ToF-AMS raw data and to extract mass concentrations for MSA from the field measurements the standard high-resolution MSA fragmentation patterns for the measurement conditions during the ship campaign (e.g. vaporizer temperature) needed to be determined.To identify characteristic air masses and their source regions backwards trajectories were used and averaged concentrations for AMS standard compounds were calculated for Correspondence to: S. R. Zorn (zorns@mpch-mainz.mpg.de) each air mass type. Sulfate mass size distributions were measured for these periods showing a distinct difference between oceanic air masses and those from African outflow. While the peak in the mass distribution was roughly at 250 nm (vacuum aerodynamic diameter) in marine air masses, it was shifted to 470 nm in African outflow air. Correlations between the mass concentrations of sulfate, organics and MSA show a narrow correlation for MSA with sulfate/sulfuric acid coming from the ocean, but not with continental sulfate.

Epidemiological studies show a clear link between increased mortality and enhanced concentrations of ambient aerosols. The chemical and physical properties of aerosol particles causing these health effects remain unclear. A major fraction of the ambient aerosol particle mass is composed of secondary organic aerosol (SOA). Recent studies showed that a significant amount of SOA consists of high molecular weight compounds (oligomers), which are chemically not well characterized. Within the POLYSOA project a large variety of state-of-the-art analytical chemical methods were used to characterize the chemical composition of SOA particles with emphasis on the oligomeric mass fraction. Mass spectrometric results showed that SOA oligomers are highly oxidized compounds and that hydroperoxides are formed, which is consistent with NMR results. This high molecular weight fraction accounts for up to 23% of the total organic carbon in SOA particles. These well-characterized SOA particles were deposited on three lung cell culture systems (microdissected respiratory epithelia from porcine tracheae, the human bronchial epithelial cell line BEAS-2B, and porcine lung surface macrophages obtained by bronchoalveolar lavage) in a newly constructed particle deposition chamber with the goal to eventually identify particle components that are responsible for cell responses leading to adverse health effects. In addition, monolayers of the alveolar epithelial cell line A549 were used in an alveolar epithelial repair model. The lung cells were examined for morphological, biochemical, and physiological changes after exposure to SOA. Analyses of the lung cells after exposure to SOA are ongoing. First data give evidence for a moderate increase of necrotic cell death as measured by lactate dehydrogenase release and for effects on the alveolar epithelial wound repair mainly due to alterations of cell spreading and cell migration at the edge of the wound. Thus, these first results indicate that SOA, in concentrations comparable to environmental concentrations, may induce distinct effects in lung cells.

Abstract. Measurements of the submicron fraction of the atmospheric aerosol in the marine boundary layer were performed from January to March 2007 (Southern Hemisphere summer) onboard the French research vessel Marion Dufresne in the Southern Atlantic and Indian Ocean (20° S–60° S, 70° W–60° E). For chemical composition measurements an Aerodyne High-Resolution-Time-of-Flight AMS was used to measure mass concentrations and species-resolved size distributions of non-refractory aerosol components in the submicron range. Within the "standard" AMS compounds (ammonium, chloride, nitrate, sulfate, organics) "sulfate" is the dominating species in the marine boundary layer reaching concentrations between 50 ng m−3 and 3 μg m−3. Furthermore, what is seen as "sulfate" by the AMS seems to be mostly sulfuric acid. Another sulfur containing species that can ubiquitously be found in marine environments is methanesulfonic acid (MSA). Since MSA has not been directly measured before with an AMS, and is not part of the standard AMS analysis, laboratory experiments needed to be performed in order to be able to identify it within the AMS raw data and to extract mass concentrations for MSA from the field measurements. To identify characteristic air masses and their source regions backwards trajectories were used and averaged concentrations for AMS standard compounds were calculated for each air mass type. Sulfate mass size distributions were measured for these periods showing a distinct difference between oceanic air masses and those from African outflow. While the peak size in the mass distribution was roughly 250 nm in marine air masses it was shifted to 470 nm in African outflow air. Correlations between the mass concentrations of sulfate, organics and MSA were calculated which show a narrow correlation for MSA with sulfate/sulfuric acid coming from the ocean but not with continental sulfate.

The precursors Fe (III) ( N−R− L)Cl ( N−R− LH 2 =N,N -bis(2 -hydroxy-5 -methyl-benzyliden)-1,7-diamino-4-R-4-azaheptane, R = H, methyl(Me)) are high-spin (S = 5/2) complexes. The Lewis-acidic precursors are combined withCl y molecular switches. The starshaped compounds are high-spin systems at room temperature. On cooling to 20 K some of the compounds exhibit multistability, i.e. several iron(III) centers within a molecule switch to the low-spin state as shown by Mössbauer spectroscopy.Keywords Heptanuclear · High-spin · Fe (III) -Fe (II) · Fe (III) -Ru (II) · Fe (III) -Co (III) · Spin crossover · Multistability Fig. 1 Formation and topology of the heptanuclear compounds (M = M 2 = Fe (II) , Co (III) , Ru (II) ) based on the mononuclear precursors [( N−H− L)Fe (III) Cl] and [( N−Me− L)Fe (III) Cl] (with R 1 = H, Methyl; R 2 = H; R 3 = Methyl(=5-Me)))

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