New Irregular Monoterpenes in Artemisia vulgaris

A gas chromatographic investigation of the steam distilled oil of the herb of Artemisia vulgaris led to the identification of 21 irregular monoterpenes of non-head-to-tail isoprenoid skeleton. The spectral data of some of these compounds are discussed. The structures of eight new irregular monoterpenes are given.     

Elucidating the fine details of cholesteric liquid crystal shell reflection patterns

ABSTRACT

Clusters of planar-aligned short-pitch cholesteric liquid crystal spheres generate dynamic colourful patterns due to multiple selective reflections from the radially oriented cholesteric helices in neighbour shells at varying distances. These photonic communication patterns were widely investigated for the cases of both droplets and shells, demonstrating not only intriguing optical phenomena but also potential for applications as new optical elements for photonics, sensing or security pattern generation. However, the optics of these clusters is truly complex and until now only the strongest and most fundamental reflections have been analysed and explained. In this report, we elucidate the origin of a number of more subtle reflections and we explain the extension in space of various spots as well as their internal colour variations.     

First example of monodispersed (Mo3Se3)1∞ clusters

The close relationship of the structure of ternary molybdenum chalcogenides to molecular cluster compounds suggests that these chalcogenides might be synthesized from such clusters or be solubilized as clusters. However, in contrast to molybdenum halide clusters which can be obtained in solution from the solid phase, many attempts to solubilize these chalcogenide clusters were unsuccessful. This is the first report that some of the pseudo-one-dimensional compounds (M₂Mo₆X₆, X = Se, Te; M = Li, Na) can be dissolved when exposed to highly polar solvents such as dimethylsulfoxide or N-methylformamide. We show using optical microscopy, TEM, and light scattering that some of these solutions contain individual (Mo₃X₃)¹_∞ chains. This is also the first example of a purely inorganic transition-metal polymer solution. The behavior with respect to flocculation is consistent with the double layer theory. We show that the (Mo₃X₃)¹_∞ chains can be oriented in solution.     

Die Bestimmung des Gesamtquecksilbers in Hydrargyrum salicylicum

Ohne Zusammenfassung     

Beschleunigtes Verfahren der Fettbestimmung in Molkereierzeugnissen

Ohne Zusammenfassung