TNT-Based condensation monomers and polymers

New aromatic diamines were obtained on the basis of available and inexpensive 2, 4, 6-trinitrotoluene (trotyl, TNT). Monomers obtained were used for the preparation of the new organo-soluble polyimides containing thiophenoxy and phenoxy side groups.     

Effect of long-range stresses on the structure of semiconductor heterosystems

The dependence between the misfit value of the interface layers f and the structural parameters of the misfit dislocations is obtained for arbitrary orientation of the interface of a semiconductor heterosystem subjected to the complete relaxation of misfit stresses. Such parameters are the distance D _i between neighboring dislocations of the ith family and projection of the edge component of the Burgers vector onto the interface (b _i ^e ). The number of families incorporated into the interface is determined by the orientation of the boundary and occurrence of the relaxation process. The role of specific cases of this expression for experimental and technological applications is discussed using the appearance of long-range shear and normal stresses in films with orientations of (001) and (111) as examples.     

Crucial role of paramagnetic ligands for magnetostructural anomalies in "breathing crystals"

Breathing crystals based on polymer-chain complexes of Cu(hfac)(2) with nitroxides exhibit thermally and light-induced magnetostructural anomalies in many aspects similar to a spin crossover. In the present work, we report the synthesis and investigation of a new family of Cu(hfac)(2) complexes with tert-butylpyrazolylnitroxides and their nonradical structural analogues. The complexes with paramagnetic ligands clearly exhibit structural rearrangements in the copper(II) coordination units and accompanying magnetic phenomena characteristic for breathing crystals. Contrary to that, their structural analogues with diamagnetic ligands do not undergo rearrangements in the copper(II) coordination environments. This confirms experimentally the crucial role of paramagnetic ligands and exchange interactions between them and copper(II) ions for the origin of magnetostructural anomalies in this family of molecular magnets.     

Intermolecular Interaction in TeO2 Crystal.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.     

Application of the R-functions method to the solution of elliptic PDEs (Poster Presentation)

In the current work, the basics of the theory of R-functions have been presented. Applications of this theory were shown on two model problems – Poisson equation and biharmonic equation – in complex two-dimensional domains both with homogeneous Dirichlet boundary conditions. The solution is performed in conjunction with the Bubnov-Galerkin method. As the basis for approximation tensor products of monomials were taken. The convergence study includes the comparison of current results with the standard finite element solution and the dependence of the number of coordinate functions on the relative error in the maximum-norm. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Study of Features of the Composition,Magnetic, and Crystal Structure of Barium Hexaferrite BaFe12 – xTixO19

Physics of the Solid State - The features of the composition, crystal, and magnetic structure of Ti-substituted barium hexaferrite BaFe12 – xTixO19 (0.25 ≤ x ≤...