Struktur und ultrarote Gitterschwingung von CaF2 und LiF

Thin films of CaF₂, LiF and LiF +20% KF are condensed on to substrates at 20 °K. Immediately after condensation and after annealing to 373 °K the infrared absorption is measured between 15 and 43 microns. Also Debye-Scherrer-diagrams are taken for investigating the structure of the layers. After condensation at 20 °K LiF has a high degree of disorder, CaF₂ and LiF+20% KF show amorphous phases. The infrared lattice vibration of such films is shifted to shorter wavelenghts.     

An explicit construction of a class of suspensions and autonomous differential equations for diffeomorphisms in the plane

From a large class of diffeomorphisms in the plane, which are known to produce chaotic dynamics, we explicitly construct their continuous suspension on a three dimensional cylinder. This suspension is smooth (C ¹) and can be characterized by the choice of two smooth functions on the unit interval, which have to fulfill certain boundary conditions. For the case of entire Cremona transformations, we are able to construct the corresponding autonomous differential equations of the flow explicitly. Thus it is possible to relate properties of discrete maps to those of ordinary differential equations in a quantitative manner. Furthermore, our construction makes it possible to study the exact solutions of chaotic differential-equations directly.     

Fresnel diffraction in deuterium

In Glauber's theory of high energy scattering the wavefunction inside the nucleus is given by geometrical optics. The theory is extended to lower energies by incorporating the effects due to Fresnel diffraction, and applied to elastic and inelastic scattering off deuterium.     

Fluorescence Properties of Donor–Acceptor-Substituted Pyrazoloquinolines

The photophysical properties of three newly synthesized pyrazoloquinolines, composed of N,N-dimethylaniline as donor subunit and various substituted forms of the acceptor pyrazoloquinoline (DPPQ), were investigated by absorption as well as by stationary and time resolved fluorescence spectroscopy. These compounds show generally highly efficient emission in nonpolar and medium polar solvents; the dipole moment of the emitting state increases and the quantum yield decreases with solvent polarity. These results are explained by state reversion in polar solvents: At low polarities emission originates from a state localized on the DPPQ moiety, whereas in the high-polarity regime the next excited state of charge transfer character, in which an electron is promoted from the amino nitrogen lone pair into an excited orbital of the DPPQ moiety, becomes the fluorescent state. This view is corroborated by semiempirical calculations including the solvent reaction field, low-temperature fluorescence measurements, and the observation of effects of protonation on the spectroscopic and photophysical properties.     

29Si- und13C-NMR-Untersuchungen zur Struktur persilylierter Urazole

The molecular structures of persilylated urazoles: tris-trimethylsilyl-urazole, bis-trimethylsilyl-4-methyl-urazole, bis-trimethylsilyl-4-methyl-dithio-urazole, and tris-trimethylsilyl-cyanurate have been determined by²⁹Si-,¹³C-NMR and IR measurements.