The formation of complexes between hexafluorophosphate (PF ) and tetraisobutyloctahydroxypyridine[4]arene has been thoroughly studied in the gas phase (ESI-QTOF-MS, IM-MS, DFT calculations), in the solid state (X-ray crystallography), and in chloroform solution ( H, F, and DOSY NMR spectroscopy). In all states of matter, simultaneous endo complexation of solvent molecules and exo complexation of a PF anion within a pyridine[4]arene dimer was observed. While similar ternary complexes are often observed in the solid state, this is a unique example of such behavior in the gas phase.

The concentrations of submicron aerosol particles in maritime regions around Antarctica are influenced by the extent of sea ice. This effect is two ways: on one side, sea ice regulates the production of particles by sea spray (primary aerosols); on the other side, it hosts complex communities of organisms emitting precursors for secondary particles. Past studies documenting the chemical composition of fine aerosols in Antarctica indicate various potential primary and secondary sources active in coastal areas, in offshore marine regions, and in the sea ice itself. In particular, beside the well-known sources of organic and sulfur material originating from the oxidation of dimethylsulfide (DMS) produced by microalgae, recent findings obtained during the 2015 PE-GASO cruise suggest that nitrogen-containing organic compounds are also produced by the microbiota colonizing the marginal ice zone. To complement the aerosol source apportionment performed using online mass spectrometric techniques, here we discuss the outcomes of offline spectroscopic analysis performed by nuclear magnetic resonance (NMR) spectroscopy. In this study we (i) present the composition of ambient aerosols over open-ocean waters across bioregions, and compare it to the composition of (ii) seawater samples and (iii) bubble-bursting aerosols produced in a sea-spray chamber onboard the ship. Our results show that the process of aerosolization in the tank enriches primary marine particles with lipids and sugars while depleting them of free amino acids, providing an explanation for why amino acids occurred only at trace concentrations in the marine aerosol samples analyzed. The analysis of water-soluble organic carbon (WSOC) in ambient submicron aerosol samples shows distinct NMR fingerprints for three bioregions: (1) the open Southern Ocean pelagic environments, in which aerosols are enriched with primary marine particles containing lipids and sugars; (2) sympagic areas in the Weddell Sea, where secondary organic compounds, including methanesulfonic acid and semivolatile amines abound in the aerosol composition; and (3) terrestrial coastal areas, traced by sugars such as sucrose, emitted by land vegetation. Finally, a new biogenic chemical marker, creatinine, was identified in the samples from the Weddell Sea, providing another confirmation of the importance of nitrogen-containing metabolites in Antarctic polar aerosols.

For the first time the formation of hexameric pyridine[4]arene capsule has been observed in gas phase, in solution and in solid state. A thermodynamic balance between capsule formation was observed, showing favour to hexamer.

The preparative resolution of a trifunctionalized C 3-symmetrical chiral cyclotriveratrylene derivative was achieved via high-performance liquid chromatography (HPLC) on a chiral stationary phase. This approach is a promising alternative to the previously reported resolution through formation of diastereomeric esters because it involves fewer synthetic steps and is less prone to thermal (re)racemization. During these studies an intermediate saddle conformer could also be isolated and characterized by 1H and 13C NMR spectroscopy. The HPLC separation method was further developed in order to allow investigations on the racemization behavior of the cyclotriveratrylene derivative.

The objective of the work presented here was the development of a method of modeling the effect of an impeller on the velocity distribution in a stirred vessel. The developed model makes it possible to numerically investigate the flow field almost independently of any experimental data. The starting point was a force balance around an impeller blade, which took into consideration the lift and drag forces. The obtained volume forces were circumferentially averaged in the impeller region. The calculations were carried out time-averaged for the case of a pitched blade impeller. The results were compared with experimental data which were obtained by laser Doppler anemometry. The comparison of the axial velocity components shows a good agreement between numerical and experimental data. Furthermore some characteristic integral values were calculated, which demonstrate the efficiency of the impeller.

<p><strong>Abstract.</strong> The concentrations of submicron aerosol particles in maritime regions around Antarctica are influenced by the extent of sea ice. This effect is two way: on one side, sea ice regulates the production of particles by sea spray (primary aerosols) while, on the other side, it hosts complex communities of organisms emitting precursors for secondary particles. Past studies documenting the chemical composition of fine aerosols in Antarctica indicate various potential primary and secondary sources active in coastal areas, in offshore marine regions as well as in the sea ice itself. In particular, beside the well-known sources of organic and sulfur material originating from the oxidation of dimethyl-sulfide (DMS) produced by microalgae, recent findings obtained during the 2015 PEGASO cruise suggest that nitrogen-containing organic compounds are also produced by the microbiota colonizing the marginal ice zone. To complement the aerosol source apportionment performed using online mass spectrometric techniques, here we discuss the outcomes of offline spectroscopic analysis performed by nuclear magnetic resonance (NMR) spectroscopy. In this study we (i) present the composition of ambient aerosols over open ocean waters across bioregions, and compared it to the composition of (ii) seawater samples and (iii) bubble bursting aerosols produced in a sea spray chamber on board the ship. Our results show that the process of aerosolization in the tank enriches primary marine particles with lipids and sugars while depleting them of free aminoacids, providing an explanation for why aminoacids occurred only at trace concentrations in the marine aerosol samples analyzed. The analysis of water-soluble organic carbon (WSOC) in ambient submicron aerosol samples shows distinct NMR fingerprints for three bioregions: 1) the open Southern Ocean pelagic environments, in which aerosols are enriched with primary marine particles containing lipids and sugars; 2) sympagic areas in the Weddell Sea where secondary organic compounds, including methanesulfonic acid and semivolatile amines abound in the aerosol composition; and 3) terrestrial coastal areas, traced by sugars such as sucrose, emitted by land vegetation. Finally, a new biogenic chemical marker, creatinine, was identified in the samples from the Weddell Sea, providing another confirmation of the importance of nitrogen-containing metabolites in Antarctic polar aerosols.</p>

Die Bildung von Wirt-Gast-Komplexen aus Hexafluorophosphat (PF 6 À )u nd Tetraisobutyloctahydroxypyridin-[4]aren (1)w urde in der Gasphase (ESI-QTOF-MS,I M-MS, DFT-Rechnungen), im Festkçrper (Rçntgenstrukturanalyse) und in Chloroformlçsungen ( 1 H-, 19 F-und DOSY-NMR) umfassend untersucht. In allen Aggregatzuständen wurde eine simultane endo-Komplexierung von Lçsungsmittelmolekülen und eine exo-Komplexierung von PF 6 À -Anionen mit dem Pyridin[4]aren-Dimer beobachtet. Während ähnliche ternäre Komplexei mF estkçrper bereits çfter beschrieben wurden, ist ein solches Verhalten in der Gasphase bislang einzigartig und noch nie zuvor beobachtet worden.

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