TY - JOUR A1 - Mikat, Jürgen E. R. A1 - Franco, Olga A1 - Regenstein, Wolfgang A1 - Reck, Günter A1 - Knochenhauer, Gerald A1 - Schulz, Burkhard A1 - Orgzall, Ingo T1 - 1,3,4-oxadiazole crystals under high pressure-phase transitions and properties Y1 - 2000 ER - TY - JOUR A1 - Schulz, Burkhard A1 - Dietzel, Birgit A1 - Orgzall, Ingo A1 - Diez, Isabel A1 - Xu, Chenggang T1 - Aspects of morphology control during the oxidative synthesis of electrically conducting polymers N2 - The formation of micro- and nanostructures during the oxidative polymerization of polypyrrole and polyaniline is investigated using different sulfonic acid dopants. Rod- or tube-like structures are found in polypyrrole as well as in polyaniline without addition of further compounds to the initial reaction mixture of monomer, dopant and oxidant. In these cases, always a crystalline precursor complex composed of a dopand molecule and the pure monomer (aniline) or a trimeric moiety (pyrrole) serves as in-situ template. In most cases the surface of the growing polymer is covered by secondary structures with much smaller sizes so that a hierarchical order of structures at different length scales results. Corresponding model considerations for the polymerization process are outlined. Additionally, unusual structures like platelets, frames, rings, or ribbons are observed in the polypyrrole synthesis in the presence of fluorosurfactants. Y1 - 2009 UR - http://hip.sagepub.com/ U6 - https://doi.org/10.1177/0954008309339933 SN - 0954-0083 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Orgzall, Ingo T1 - Cluster shapes in the continuum description of percolating networks Y1 - 1995 ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Dietzel, Birgit A1 - Schulz, Burkhard A1 - Reck, Guenter A1 - Hoffmann, Angelika A1 - Orgzall, Ingo A1 - Resch-Genger, Ute A1 - Emmerling, Franziska T1 - Combined structural and fluorescence studies of methyl-substituted 2,5-diphenyl-1,3,4-oxadiazoles - Relation between electronic properties and packing motifs JF - Journal of molecular structure N2 - Prerequisite for the rational design of functional organic materials with tailor-made electronic properties is the knowledge of the structure-property relationship for the specific class of molecules under consideration. This encouraged us to systematically study the influence of the molecular structure and substitution pattern of aromatically substituted 1,3,4-oxadiazoles on the electronic properties and packing motifs of these molecules and on the interplay of these factors. For this purpose, seven diphenyl-oxadiazoles equipped with methyl substituents in the ortho- and meta-position(s) were synthesized and characterized. Absorption and fluorescence spectra in solution served here as tools to monitor substitution-induced changes in the electronic properties of the individual molecules whereas X-ray and optical measurements in the solid state provided information on the interplay of electronic and packing effects. In solution, the spectral position of the absorption maximum, the size of Stokes shift, and the fluorescence quantum yield are considerably affected by ortho-substitution in three or four ortho-positions. This results in blue shifted absorption bands, increased Stokes shifts, and reduced fluorescence quantum yields whereas the spectral position and vibrational structure of the emission bands remain more or less unaffected. In the crystalline state, however, the spectral position and shape of the emission bands display a strong dependence on the molecular structure and/or packing motifs that seem to control the amount of dye-dye-interactions. These observations reveal the limited value of commonly reported absorption and fluorescence measurements in solution for a straightforward comparison of spectroscopic results with single X-ray crystallography. This underlines the importance of solid state spectroscopic studies for a better understanding of the interplay of electronic effects and molecular order. KW - Diphenyl-oxadiazoles KW - X-ray structure KW - Packing motif KW - Optical properties KW - Fluorescence quantum yield Y1 - 2011 U6 - https://doi.org/10.1016/j.molstruc.2010.11.071 SN - 0022-2860 VL - 988 IS - 1-3 SP - 35 EP - 46 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Orgzall, Ingo A1 - Lorenz, Bernd T1 - Computer simulation of microstructures and geometric properties of a random system of penetrable disks : a model for compacted powders Y1 - 1994 ER - TY - JOUR A1 - Orgzall, Ingo A1 - Lorenz, H. A1 - Hinze, E. T1 - Formation of cubic BN in the system Mg3N2-BN : some pecularities Y1 - 1994 ER - TY - JOUR A1 - Orgzall, Ingo A1 - Lorenz, H. T1 - Formation of cubic boron nitride in the system Mg3N2-BN : a new contribution to the phase diagram Y1 - 1995 ER - TY - JOUR A1 - Orgzall, Ingo A1 - Lorenz, H. A1 - Hinze, E. T1 - Formation of the intermediate compound Mg3BN3 in the system Mg3N2-BN Y1 - 1994 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Orgzall, Ingo A1 - Dorhout, P. K. A1 - Casey, R. A1 - D'Adamo, R. A1 - Hochheimer, H. D. T1 - High pressure optical and Raman investigations of the ternary compound Cs2MoS4 Y1 - 1996 ER - TY - JOUR A1 - Orgzall, Ingo A1 - Franco, Olga A1 - Schulz, Burkhard T1 - High pressure structural investigations of 2,5-di(4-pyridyl)-1,3,4-oxadiazole - importance of strain studies for the description of intermolecular interactions N2 - Results of a high pressure x-ray study of 2,5-di(4-pyridyl)-1,3,4-oxadiazole up to 2.5 GPa are presented and discussed. Parameters for the Murnaghan equation of state are derived. The bulk modulus amounts to K-0 = 4.6 +/- 0.3 GPa and its pressure derivative to K-0' = 7.4 +/- 0.6. These values are comparable to values of other diphenyl-1,3,4- oxadiazoles. The anisotropy of the compression is analysed using the strain tensor and discussed based on the anisotropy of the intermolecular interactions Y1 - 2006 UR - http://iopscience.iop.org/0953-8984 U6 - https://doi.org/10.1088/0953-8984/18/23/001 ER -