First structural characterization of neutral, base-stabilized group 15-pentaazides: single crystal X-ray structures of dmap-As(N3)5 and dmap-Sb(N3)5

Two neutral group 15-pentaazides dmap-As(N(3))(5) (1) and dmap-Sb(N(3))(5) (2) were synthesized and structurally characterized for the first time (dmap = 4-dimethylaminopyridine). Base-stabilization was confirmed to be very suitable for the kinetic stabilization of highly explosive covalent main group polyazides.     

Stereoselective Synthesis of Polycyclic Thiopyrans

The reaction of benzothiete ( 1 ) and the bicyclic alkenes 5 , 7 , 9 , or 12 shows a very high π side selectivity (de > 95%) in the formation of the polycyclic thiopyrans 6 , 8 , 10 , 11 , 13 , and 14 .     

Derivatives of Bis(diphenylphosphino)maleic Anhydride as Ligands in Polynuclear Gold(I) Complexes

Based on the new binuclear gold(I) complex [(AuCl)₂(L1)] (1) (L1?=?2,3-bis(diphenylphosphino)maleic anhydride) four new polynuclear compounds were synthesized by reactions of 1 with E(SiMe₃)₂ (E?=?S, Se). During the formation of these new compounds the initial ligand L1 undergoes various transformations (e.g. substitution, hydration or hydrogenation) leading to the new ligands: trans-2,3-bis(diphenylphosphino)succinic anhydride (L2), 2-diphenylphosphino-3-mercapto-maleic anhydride anion (L3), 2-diphenylphosphino-3-selenolato-maleic anhydride anion (L4) and 2,3-bis(diphenylphosphino)succinic acid (L5). In case of using the sulfur species S(SiMe₃)₂ a pentanuclear cluster, [Au₅(PPh₂)₃(L3)₂] (2), and a 24-nuclear cluster, [Au₂₄S₆(PPh₂)₄(L3)₈] (3), could be obtained. With Se(SiMe₃)₂ the binuclear complex, [(AuCl)₂(L2)] (4), and the dodecanuclear cluster, [Au₁₂Se₄(L4)₄(L5)₂] (5), were yielded.     

Iso-surface Computation in 3D using a graph-theoretical Approach

The existing combinatorial methods for iso-surface computation are efficient for pure visualization purposes, but it is known that the resulting iso-surfaces can have holes, and topological problems like missing or wrong connectivity can appear. To avoid such problems, we introduce a graph-theoretical method for the computation of iso-surfaces on cuboid meshes in ℝ³. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Tetragonal polymorphic modification of tetrakis­(N,N‐diethyl­di­thio­carbam­ato‐S,S′)­tellurium(IV)

During an investigation of the W/Te/Br₂ system, we prepared crystals of the title compound, C₂₀H₄₀N₄S₈Te, from aceto­nitrile solution by slow addition of diethyl ether. It appeared to be a new tetragonal modification. The calculated density of the tetragonal modification (1.513 Mg m^?3) is slightly greater than found for the known orthorhombic modification (1.46 Mg m^?3). The bond distances and angles are practically the same.     

Experimental and numerical investigation of shock wave-loaded plates

In the present paper measured and simulated vibrations of viscoplastic plates under impulsive loadings are compared to each other. The aim is to determine how accurately the measured deformations can be calculated by the chosen constitutive and structural theories. The damage growth in the plate specimens until failure is predicted by finite element simulations and compared to shock tube experiments. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Polypeptide‐Shelled Poly(propylene imine) Dendrimers and Their Complexing Properties towards Copper(II) Ions

Summary: Polypeptide‐shelled poly(propylene imine) dendrimers were realized by ring‐opening polymerization of α‐amino acid N‐carboxyanhydrides, initiated by dendrimers as core molecules. Polypeptides with 2nd generation core were used as model compounds to investigate interior complexes between metal ion and surface‐modified dendrimers. Micro‐calorimetric measurements outlined the formation of approximate 1:1 complexes between Cu^II and polypeptide‐shelled dendrimers and the influence of polypeptide chain compositions on differential molar heats of complexation.

Composition of one of the polypeptides synthesized.     

Evolutionarily stable sets

This paper provides definitions for the evolutionary stability of sets of strategies based on simple fitness comparisons in the spirit of the definition of an evolutionarily stable strategy (ESS) by Taylor and Jonker (1978). It compares these with the set-valued notions of Thomas (1985d) and Swinkels (1992). Provided only that the fitness function is analytic, our approach yields an alternative characterization of Thomas' evolutionarily stable sets (ES Sets) which does not rely on the structure or topology of the underlying strategy space. Moreover, these sets are shown to have a very special geometric structure and to be finite in number. For bimatrix games ES Sets are shown to be more uniformly robust against mutations than apparent from the definition and hence to be equilibrium evolutionarily stable sets in the sense of Swinkels (1992). Received November 1995/Final version December 2000