Eigenfrequency analysis of cable structures with inclined cables

The approximate eigenfrequencies for the in-plane vibrations of a cable struc- ture consisting of inclined cables,together with point masses at various points were com- puted.It was discovered that the classical transfer matrix method was inadequate for this task,and hence the larger exterior matrices were used to determine the eigenfrequency equation.Then predictions of the dynamics of the general cable structure based on the asymptotic estimates of the exterior matrices were made.     

Local field dynamics in a resonant quantum tunneling system of magnetic molecules

We observed non-exponential relaxation for a quantum tunneling molecular magnetic system at very low temperatures and argue that it results from evolving intermolecular dipole fields. At the very beginning of the relaxation, the magnetization follows a square-root time dependence. A simple model is developed for the intermediate time range that is in good agreement with the data over 4 decades in time. Detailed numerical calculations as well as measurements are presented which indicate unusual correlation effects in these systems. Received: 15 May 1998 / Revised: 10 July 1998 / Accepted: 11 July 1998     

Spectroscopic and theoretical studies on a three-iron cluster with linear arrangement

The linear trinuclear iron complex Fe₃(SPh)₆(CO)₆ with bridging benzenethiolate ligands is the subject of temperature- and field-dependent Mössbauer studies. The results reveal the two terminal iron atoms to be diamagnetic (Fe(II) and the central iron atom to be high-spin Fe(II). The magnetic Mössbauer pattern of the latter is dominated by a positive (!) internal field. Complementary to the experimental studies, also theoretical studies are performed. Local density molecular orbital and ligand-field calculations yield an orbitally degenerate ground state that accounts for the unusual electronic and spectroscopic properties.     

Molecular surface electrostatic potentials in the analysis of non-hydrogen-bonding noncovalent interactions

Electrostatic potentials computed on molecular surfaces are used to analyse some noncovalent interactions that are not in the category of hydrogen bonding, e.g. “halogen bonding”. The systems examined include halogenated methanes, substituted benzenes,s-tetrazine and l,3-bisphenylurea. The data were obtained byab initio SCF calculations.     

Synthese der pentasaccharid-sequenz der repeating-unit der o-spezifischen seitenkette des lipopolysaccharides von shigella dysenteriae

The pentasaccharide sequence $\text{1}$, representing the lipopolysaccharide repeating unit from shigella dysenteriae serotype 2, has been synthesised. This branched-chain pentasaccharide contains exclusively α-linked glycosidic bonds. Our methods in selectivega-glycoside synthesis have been confirmed by the synthetic route.