Ionization of aniline and its N-methyl and N-phenyl substituted derivatives by (free) electron transfer to n-butyl chloride parent radical cations

The electron transfer from aniline and its N-methyl as well as N-phenyl substituted derivatives (N-methylaniline, N,N-dimethylaniline, diphenylamine, triphenylamine) to parent solvent radical cations was studied by electron pulse radiolysis in n-butyl chloride solution. The ionization results in the case of aniline (ArNH2) and the secondary aromatic amines (Ar2NH, Ar(Me)NH) in the synchronous and direct formation of amine radical cations, as well as aminyl radicals, in comparable amounts. Subsequently, ArNH2*+ deprotonates in a delayed reaction with the present nucleophile Cl-, and forms further ArNH*. In contrast, tertiary aromatic amines such as triphenylamine and dimethylaniline yield primarily the corresponding amine radical cations Ar3N*+ or Ar(Me2)N*+, only. The persistent Ar3N*+ forms a charge transfer complex (dimer) with the parent amine molecule, whereas Ar(Me2)N*+ deprotonates to carbon-centered radicals Ar(Me)NCH2*.     

N,N′-Linked 1,2-benzisothiazol-3(2H)-one 1,1-dioxides: synthesis, biological activity, and derived radicals

A number of N,N′-linked benzoannelated isothiazol-3(2H)-one 1,1-dioxides, not available via oxidation of isothiazolium salts, were obtained with good yields by reaction of N-amino heterocycles with 2-chlorosulfonylbenzoyl chloride and evaluated for their inhibitory activity toward human leukocyte elastase (HLE) and acetylcholinesterase (AChE). 2-(Phthalimid-1-yl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide and 2-(2-methyl-4-oxo-3(4H)-quinazolinyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide were found to be inhibitors of HLE and tested as potential precursors of nitrogen-centered radicals using 266 nm laser flash photolysis.     

The study of stabilizer action modes by means of time-resolved techniques: Intermediate radical cations

In organic systems, radiation- and photo-induced electron transfer reactions result in the first step in the formation of radical cations. With pulse radiolysis and laser photolysis experiments radical cations of phenols could be indirectly characterized whereas radical cations of sterically hindered amines (HALS compounds) could be directly observed.     

Time-resolved optical absorption spectroscopy of molten polyethylene blends

By means of pulse radiolysis and laser photolysis experiments with detection by optical absorption spectroscopy short-living radical transients in pure PE and in PE doped with additives (e.g. di->tert-butyl-p-cresol, diphenylamine, benzophenone and carbon tetrachloride) were characterized by their optical absorption spectra and kinetics. It was found that the additive radicals were formed in a very fast process probably via exciton migration and subsequent energy transfer and dissociation reactions.     

Zur Chevalley-Zerlegung von Derivationen

Let k be a valued field of characteristic zero. We consider analytic k-algebras, i.e. finite algebras over rings of convergent power series over k, and their k-derivations. The following theorem is proved: Let k be algebraically closed and A a normal analytic k-algebra of dimension 2. If there is a k-derivation on A not acting nilpotently, then A is homogeneous, i.e. a residue class ring of a power series ring by a (weighted) homogeneous ideal.The basic tool is the Chevalley decomposition of k-derivations of analytic algebras. We also use some general lemmata concerning extensions and restrictions of k-derivations which describe homogeneity.     

Über die Divisorenklassengruppen lokaler Ringe auf zweidimensionalen normalen Hyperflächen

Ohne ZusammenfassungDer Erstgenannte der Verfasser wurde bei der Vorbereitung dieser Arbeit von der Purdue Research Foundation unterstützt.     

Theory of light amplification in active fishnet metamaterials

We establish a theory that traces light amplification in an active double-fishnet metamaterial back to its microscopic origins. Based on ab initio calculations of the light and plasmon fields we extract energy rates and conversion efficiencies associated with gain and loss channels directly from Poynting's theorem. We find that for the negative refractive index mode both radiative loss and gain outweigh resistive loss by more than a factor of 2, opening a broad window of steady-state amplification (free of instabilities) accessible even when a gain reduction close to the metal is taken into account.     

Fortsetzungssätze der komplex-analytischen Cohomologie und ihre algebraische Charakterisierung

Ohne ZusammenfassungDer vorliegenden Arbeit liegen die Abschnitte 1 bis 4 von Kapitel I der Habilitations-schrift [9] des Verfassers zugrunde; über diese Ergebnisse wurde bereits auf der Arbeitstagung Komplexe Analysis in Oberwolfach im März 1962 berichtet. Kapitel II von [9] wurde unter [10] veröffentlicht.