Darstellung,eigenschaften und umsetzungen von (β-alkoxycarbonyl-alkyliden)-ammoniumsalzen

Iminium salts 3 and 5 are accessible by alkylation or protonation of β-alkoxycarbonyl-enamines. They have been isolated and characterized by ¹H NMR spectra. Their reaction products formed with nucleophiles such as organomagnesium or CH-acidic compounds (dimedone, acetophenone), are also investigated and shown partly to undergo secondary reactions under amine elimination.     

Nicht-lineare Biegungsschwingimgen des Kreisringes

Ohne Zusammenfassung     

Magnetic resonance experiments on the radical cation salt (fluoranthenyl)2+ PF6−. Correlation of proton-NMR,fluorine-NMR and ESR

The longitudinal relaxation rates of the protons and the fluorine were determined for the radical cation salt (fluoranthenyl)₂⁺PF₆^? as a function of the temperature. These data are compared with the temperature dependence of the pulsed ESR signal amplitude at the same Larmor frequency (44 MHz). Whereas the fluorines are relaxed mainly by the reorientational motion of the anions and by the interaction with fixed paramagnetic impurities, the protons are relaxed additionally above 150 K predominantly by highly mobile paramagnetic species, whose concentration could be determined directly via the signal amplitudes of the NMR and ESR signals in the same set up. The Pauli susceptibility χ_c^s = 3.1 ×10^?5 cm³/mole which is derived from this experiment and the Korringa relation (T_1H4^?)^?1 = constant of the proton relaxation leads to the assumption of a metal-like behavior of the salt above 183 K. The observation that the protons of the cation stacks, rather than the fluorines on the anions are relaxed by the mobile paramagnetic species favors the assumption of one-dimensional spin transport within the fluoranthenyl stacks, which is further supported by an ω^{$\text{?1}\text{2}$} dependence of T_1H^?1.     

Evidence on the influence of fission channels on fission phenomena

Partial fission channel widths can be extracted from fission cross-section analysis only up to a rotation in the space of fission vectors. We propose to obtain a physically significant basis for fission vectors taking into account information from other fission characteristics such as the valley-to-peak ratio of the mass distribution and the number of prompt neutrons emitted per fission event. Fission widths and other channel characteristics are calculated for 0⁺ resonances in low energy neutron induced fission of ²³⁹Pu.     

On a new metric affine theory of gravitation

We present three hypotheses which underlie a new general relativistic theory of gravitation for microphysical systems. According to this theory the metric and the independent affine connection of spacetime are determined by the momentum current and the newly recognized “hypermomentum” current of matter.     

Rotational diffusion of dyes in micellar media from transient absorption

Solubilizer effects in dye solutions have been investigated by subnanosecond laser-pulse photometry. Different models for the transient dichroism of dye-micelle solutions are proposed. Computer fits of the experimental curves indicate that the model where dye molecules rotate within the liquid-like interior of the micelles is the most realistic one. Since the measured rotational diffusion times differ for different dyes in almost the same way as for pure highly-viscous solvents, the dye molecules do not act merely as labels for the rotation of the micelles, but rotate themselves considerably. It is shown that the rotational diffusion of dye molecules and micelles can be separated giving reasonable results for the size of the micelles. The results are compared with previous steady-state experiments.