Etude photochimique des benzo(A)- et benzo(C)acridines par CIDNP

Photoreactions of benzo(a)- and benzo(c)acridines in protic solvents were studied by CIDNP. Two routes to adducts are possible: direct recombination in the first radical pair (S state) or recombination of radicals after diffusion. The relative importance of each route seems to be linked to the presence of the benzo group and to solvent reactivity.     

Photochemical reactions of Ru3(CO)12 involving metalmetal bond fission

Photolysis of Ru₃(CO)₁₂ in the presence of donor ligands rapidly produces monomeric ruthenium species.     

Mass spectral study on thiazolo[3,2-a]benzimidazoles. Studies on heterocyclic compounds. IV

Condensation of α-halocarbonyl compounds and 2-mercaptobenzimidazole gives thiazolo-[3,2-a]benzimidazoles. This condensation occurred at the mercapto group of the benzimidazole followed by cyclization to form the thiazole ring. This was confirmed by the examination of the mass spectra of 2- and 3-methylthiazolo[3,2-a]benzimidazoles, 2- and 3-phenylthiazolo[3,2-a]-benzimidazoles, and their derivatives.     

Bestimmung von Arsen mittels Atomabsorption

Zusammenfassung Arsen wird mittels Atomabsorptionsspektrometrie bei den Wellenlängen 1890,4 Å und 1972,6 Å bestimmt. Als Absorptionsküvette wird ein Graphitrohr in einer Argonkammer verwendet. Um die in diesem Wellenlängenbereich auftretenden Störungen bei der Absorptionsmessung zu vermindern, wird eine Bezugsintensität bei einer benachbarten Wellenlänge mitgemessen. Dadurch ist es möglich, Arsen in Lösungen in einer Menge bis zu 1 ng oder in einer Konzentration bis zu 0,1 g/ml zu bestimmen.

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Summary Arsenic has been determined with atomic-absorption spectrometry at the wavelengths 1890,4 and 1972,6 Å. A graphite tube in an argon chamber was used as an absorption cell. In order to diminish the fluctuations in absorption measurements in this wavelength region a control intensity was measured at a neighbouring wavelength. By this method it was possible to determine arsenic in a solution in quantities down to 1 ng or in concentrations down to 0.1 g/ml.

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Herrn Prof. Dr. H.Kaiser zum 60. Geburtstag gewidmet.

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Meiner Mitarbeiterin FräuleinErika Schackmann danke ich für sorgfältige Messungen und manche Anregung.     

Chromatographie und Elektrophorese von Histamin

Ohne Zusammenfassung