Numerisch genaue Lösungen des nichtlokalen Schalenmodells

The nonlocal Schrödinger-equation has been solved in the shell model case with a kernel-function, which is well known from optical model calculations. Now in the eigenvalue region the energies, as well as the wave-functions, of the exact and the approximate nonlocal calculations (E andE ₀) differ slightly on the average. The exact solutions show in general larger energy-level distances. Although these differences are small, fitting of experimental neutron binding-energies requires nevertheless a relatively big change of the set of physical parameters; the exact nonlocal calculations tend to larger potential depthV and smaller radius constantr ₀ than the approximate nonlocal ones. For the wave-functions (Φ andΦ ₀) it can be shown that an application of the Perey-effect leads to a wrong result in the shell model case. Here the difference function shows two inflection points, whereas there is only one in the optical model. The form of nuclear matter distribution thus becomes more potential-like. The eigenfunctions of the exact nonlocal calculation are orthogonal, whereas the local equivalent ones are not.     

Comparative molecular field analysis of CCK-A antagonists using field-fit as an alignment technique. A convenient guide to design new CCK-A ligands

Summary Comparative molecular field analysis (CoMFA) has been used as a three-dimensional quantitative structure-activity relationship (QSAR) method to correlate the affinities of several antagonists towards CCK-A receptors with their steric and electrostatic fields. In this publication, we describe, for the first time, a field-fit operation as an alignment technique. These results could serve as a guide for the design of new non-peptide antagonists.     

Measurement of Raman scattering in simple liquids under the influence of high quasi-static electric fields

The vibrational Raman bands of some simple liquids are investigated on the influence of an external electric dc field. Thereby the electric field strength is varied in the range of 0.1 to 1 MV/cm. The experiments demonstrate that Raman intensities and depolarization ratios increase with increasing field strength and — after passing a maximum — decrease with even higher field strengths. In mixtures the field dependence of Raman intensity takes a different course than in pure liquids.     

Über den Zusammenhang zwischen Struktur und Stabilität von Hydrazinsulfonamiden

Syntheses of twenty new hydrazinesulfonamides are described, and structure-stability relationships and decomposition-mechanisms of these compounds are discussed.

     

Negative ion liquid secondary ion mass spectrometry of carbamate-linked oligodeoxynucleosides. II

Carbamate-linked Oligodeoxynucleosides, in which the backbone consists of carbamate and N-methylcarbamate linkages, have been analyzed by negative ion liquid secondary ion mass spectrometry. Bidirectional sequence-determining fragmentations are postulated to occur from a common radical anion intermediate that is produced by capture of an ionizing electron by the neutral sample molecule. Fragmentation reactions appear to be related to whether a proton or methyl group is present on the amide nitrogen.     

Neue 1,1′-Ferrocendichalkogenato-Komplexe des Rutheniums und Osmiums

New 1,1′-Ferrocene Dichalcogenato Complexes of Ruthenium and Osmium Both trinuclear 1,1′-ferrocene dichalcogenato complexes(¹) such as fc(E[ML_n])₂ ( 1a—c ) (with [ML_n] = Ru(CO)₂Cp*; E = S, Se, Te) and dinuclear [3]ferrocenophane derivatives of the type fcE₂[ML_n] (with [ML_n] = Ru(CO)(η⁶-C₆Me₆) ( 2a, b ), Ru(NO)Cp* ( 3a, b ) (E = S, Se) or Os(NO)Cp* ( 4a—c ) (E = S, Se, Te)) were synthesized and characterized by their IR-, ¹H- and ¹³C NMR spectra as well as their mass spectra. The molecular structure of fcS₂[Os(NO)Cp*] ( 4a ) was determined by an X-Ray structure analysis; the long Fe…?Os distance of 431.1(1)pm excludes any direct bonding interactions.