TY - JOUR A1 - Díez, I. A1 - Emmerling, Franziska A1 - Malz, Frank A1 - Jäger, Christian A1 - Schulz, B. A1 - Orgzall, I. T1 - Origin of templating processes in polypyrrole synthesis N2 - The supermolecular mechanism of the template-mediated oxidative polymerization of pyrrole is investigated in detail. It is shown for the first time that 2,5-bis(pyrrol-2-yl)pyrrolidyl complexes with aromatic sulfonic acids such as %#946;-naphtalenesulfonic acid or para-toluenesulfonic acid are formed in the early polymerization step. The crystalline acid–base complexes are isolated and their crystal structures are analyzed. A 2,5-bis(pyrrol-2-yl)pyrrolidyl cation is common to both complexes and forms an inner salt with the sulfonic acid anion. As concluded from NMR investigations the synthesis using sulfonic acids results in a high stereo selectivity with respect to the trans conformation of the pyrrolidyl ring compared with the classical synthesis routine of this compound using hydrochloric acid. The needle-like crystals of the complexes act as hard templates during the next step of the polymerization and result in tubular morphologies of the polypyrrole. KW - Polypyrrole KW - Pyrrole complex PY - 2008 DO - https://doi.org/10.1016/j.matchemphys.2008.05.057 SN - 0254-0584 VL - 112 IS - 1 SP - 154 EP - 161 PB - Elsevier CY - Amsterdam AN - OPUS4-17859 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franco, O. A1 - Reck, Günter A1 - Orgzall, I. A1 - Schulz, Burkhard A1 - Schulz, B. T1 - Characterization of a new non-centrosymmetric polymorph of diphenyl-1,3,4-oxadiazole N2 - Diphenyl-1,3,4-oxadiazole (DPO) crystallization experiments from solutions clearly reveal the polymorphism of the substance. Besides the formerly known centrosymmetric monoclinic structure with space group P21/c (DPO I) a new monoclinic structure with the non-centrosymmetric space group Cc is found (DPO II): a=2.4134(4) nm, b=2.4099(3) nm, c=1.2879(2) nm,?=110.048(3)°, and V=7.0363(17) nm3. The asymmetric unit contains six independent molecules in a complex packing motif. A re-determination of the crystal structure of DPO I at room temperature gives lattice parameters a=0.51885(6) nm, b=1.8078(2) nm, c=1.21435(14) nm, ?=93.193(3)°, and V=1.1373(2) nm3. X-ray measurements at 363 K show a significant increase of the unit cell volume by 1.6%. Differences between both structures concerning morphology and characteristic Raman bands are outlined in detail. DSC investigations show an irreversible transition from DPO I to DPO II at 97 °C. DPO II does not show any transition in the temperature range up to the melting point at 141 °C. The non-centrosymmetric DPO II structure shows triboluminescence. KW - Diphenyl-1,3,4-oxadiazole KW - X-ray structure KW - Polymorphism KW - Non-centrosymmetric structure PY - 2003 DO - https://doi.org/10.1016/S0022-2860(02)00569-0 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 649 SP - 219 EP - 230 PB - Elsevier CY - Amsterdam AN - OPUS4-2465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franco, O. A1 - Reck, Günter A1 - Orgzall, I. A1 - Schulz, B. T1 - Structure and high pressure behaviour of organic crystals based on aromatically substituted 1,3,4-oxadiazoles KW - C. High pressure KW - D. Equations-of-state KW - D. Crystal structure PY - 2002 SN - 0022-3697 VL - 63 SP - 1805 EP - 1813 PB - Pergamon Press CY - New York, NY AN - OPUS4-1555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reck, Günter A1 - Orgzall, I. A1 - Schulz, B. T1 - 2,5-Di-p-tolyl-1,3,4-oxa­diazo­le N2 - The mol­ecule of the title compound, C16H14N2O, consists of two equivalent parts related by a twofold axis of the space group. The O atom occupies a special position on this twofold axis. PY - 2003 DO - https://doi.org/10.1107/S1600536803014867 SN - 1600-5368 VL - 59 IS - 8 SP - o1135 EP - o1136 PB - Munksgaard CY - Copenhagen AN - OPUS4-2609 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reck, Günter A1 - Orgzall, I. A1 - Schulz, B. A1 - Dietzel, B. T1 - Two polymorphic forms of 2,5-bis(4-methoxycarbonylphenyl)-1,3,4-oxadiazole N2 - In the title compound, C13H14BN3O, the aziridine ring is an almost equilateral triangle, the C—C distance being slightly shorter than the C—N distances, probably because of the dative B—N bond. The five-membered ring, composed of two C atoms and N, B and O atoms, is fused with the aziridine ring to form a six-membered ring with a chair conformation. PY - 2003 DO - https://doi.org/10.1107/S0108270103022698 SN - 0108-2701 SN - 1600-5759 VL - 59 SP - o634 EP - o635 PB - Blackwell Publ. CY - Oxford AN - OPUS4-2694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Orgzall, I. A1 - Reck, Günter A1 - Schulz, Burkhard A1 - Stockhause, S. A1 - Schulz, B. T1 - Structures of substituted di-aryl-1,3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution N2 - Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of π–π interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal–organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed. KW - Crystal structure KW - 1,3,4-Oxadiazole KW - Molecular conformation KW - Hydrogen bonds PY - 2006 DO - https://doi.org/10.1016/j.molstruc.2006.03.076 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 800 IS - 1-3 SP - 74 EP - 84 PB - Elsevier CY - Amsterdam AN - OPUS4-13799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orgzall, I. A1 - Emmerling, Franziska A1 - Schulz, B. A1 - Franco, O. T1 - High-pressure studies on molecular crystals - relations between structure and high-pressure behavior N2 - This paper summarizes attempts to understand structure–property relationships for a large class of aromatic diphenyl-1,3,4-oxadiazole molecules. Starting from the investigation of the crystal structure several common packing motifs as well as characteristic differences are derived. Many different molecules show a rather planar conformation in the solid state. A stronger intermolecular twist is only observed for compounds with substituents occupying the ortho-positions of the phenyl rings. Most crystal structures are characterized by the formation of stacks leading to intense π–π acceptor–donor interactions between oxadiazole and phenyl rings. High-pressure investigations result in a soft compression behavior typical for organic molecular crystals. The bulk behavior may be described by the Murnaghan equation of state with similar coefficients (bulk modulus and its pressure derivative) for nearly all investigated compounds but also for related substances. The compression shows a strong anisotropy resulting from the specific features and packing motifs of the crystal structure. This is clearly indicated by a corresponding strain analysis. Additionally to the crystal structure the Raman spectrum was also investigated under increasing pressure. The different pressure behavior of external and internal modes reflects the difference between intra- and intermolecular interactions. KW - Diphenyl-1,3,4-oxadiazole KW - Crystal structure KW - High pressure investigations KW - Equation of state KW - Strain analysis KW - Raman investigations PY - 2008 DO - https://doi.org/10.1088/0953-8984/20/29/295206 SN - 0953-8984 SN - 1361-648X VL - 20 SP - 295206-1 - 295206-15 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-17784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Reck, Günter A1 - Kraus, Werner A1 - Orgzall, I. A1 - Schulz, B. T1 - Structure determination of two asymmetrically substituted oxadiazoles from powder diffraction data N2 - The crystal structures of the 1,3,4 oxadiazole compounds N,N-dimethyl-N-[4-(1,3,4-oxadiazol-2-yl)phenyl]amine (1) and 2-methyl-5-phenyl-1,3,4-oxadiazole (2) have been determined. In case of 1 no adequate crystals were available; therefore the structure was solved at room temperature from X-ray powder diffraction data using the method of simulated annealing. This solution is compared to a second one obtained by applying the molecular replacement method. Subsequent Rietveld refinements combined with the so called two stage method based on the data collected to 1.6 Å resolution yielded an Rwp value of 7.27% for 1. Compound 1 crystallizes in the orthorhombic space group P212121 with lattice parameters of a = 7.599(4) Å, b = 6.004(2) Å, c = 21.736(3) Å. The crystal structure of 2 was solved by means of single crystal structure analysis (monoclinic space group P21/c, a = 8.010(3) Å, b = 10.783(4) Å, c = 19.234(7) Å, β = 90.794(9)°). KW - Crystal structure KW - Oxadiazoles KW - Powder diffraction X-ray investigations KW - Structure determination PY - 2008 DO - https://doi.org/10.1002/crat.200711053 SN - 0023-4753 SN - 1521-4079 SN - 0232-1300 VL - 43 IS - 1 SP - 99 EP - 107 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-16582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Orgzall, I. A1 - Dietzel, B. A1 - Schulz, Burkhard A1 - Reck, Günter A1 - Schulz, B. T1 - Structural studies on trifluoromethyl substituted 2,5-diphenyl-1,3,4-oxadiazoles N2 - Three new compounds have been synthesized based on the molecular motif 2-[2,6-bis(trifluoromethyl)phenyl]-5-phenyl-1,3,4-oxadiazole, with subsequent CF3-substitution in the ortho-positions of the phenylene ring. The crystal structures of the compounds have been determined by single crystal X-ray diffraction. All compounds have a monoclinic structure. The solid state structure of the compounds is influenced by the electronic properties of the fluorine atoms, leading to the occurrence of C–H...F, and C–F...ϖ interactions, partly replacing ϖ–ϖ interactions usually observed in the crystal structures of 2,5-diphenyl-1,3,4-oxadiazole derivatives. Other significant interactions than those involving fluorine appear only in rare cases. The strong impact of the fluorine atoms on the intra- and intermolecular interactions, and the molecular conformation lead to novel inputs for the understanding of molecular recognition, supramolecular assembly, and crystal packing of fluorine containing compounds. KW - Crystal structure KW - 1,3,4-oxadiazole KW - Molecular conformation KW - Weak interactions PY - 2007 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 832 IS - 1-3 SP - 124 EP - 131 PB - Elsevier CY - Amsterdam AN - OPUS4-14644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Orgzall, I. A1 - Dietzel, B. A1 - Schulz, B. A1 - Larrucea, J. T1 - Ordering the amorphous - Structures in PBD LED materials N2 - The class of 2,5 disubstituted-1,3,4-oxadiazoles containing a biphenyl unit on one side is intensively used as electron transport materials to enhance the performance of organic light emitting diodes (OLEDs). In contrast to the ongoing research on these materials insights in their structure-property relationships are still incomplete. To overcome the structural tentativeness and ambiguities the crystal structures of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, that of the related compound 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole and of 2-(4-biphenylyl)-5-(2,6-dimethylphenyl)-1,3,4-oxadiazole are determined. A comparison with the results of GAUSSIAN03 calculations and similar compounds in the Cambridge Structural Database leads to a profound characterization. KW - OLED KW - PBD KW - Diphenyl-1,3,4-oxadiazole KW - Crystallization PY - 2012 DO - https://doi.org/10.1016/j.molstruc.2012.04.040 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 1030 SP - 209 EP - 215 PB - Elsevier CY - Amsterdam AN - OPUS4-27264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -