TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald A1 - Dietel, Reinhard A1 - Freydank, Anke-Christine A1 - Zetzsche, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig A1 - Barberka, Thomas Andreas A1 - Geue, Thomas T1 - Structure of thermally treated oxadiazoleamide Langmuir-Blodgett films N2 - The thermal treatment of Y-type Langmuir-Blodgett (LB) films formed from the amphiphilic derivative of 2,5- diphenyl-1,3,4-oxadiazole 1 results in changes of the molecular packing. These changes have been analysed by a combination of X-ray specular reflectivity data, X-ray grazing incidence diffraction data and scanning force microscopy images, On the basis of these experimental data we have simulated possible supramolecular structures, These simulations provide insight into the intermolecular interactions giving rise to the observed structural transitions. The crystalline structure induced by thermal treatment of the LB films is characterized by a uniaxial texture, which is correlated with the dipping direction during deposition of the LB film. Y1 - 1997 ER - TY - JOUR A1 - Paschke, K. A1 - Geue, Thomas A1 - Barberka, Thomas Andreas A1 - Bolm, A. A1 - Pietsch, Ullrich A1 - Rösch, M. A1 - Batke, Edwin A1 - Faller, F. A1 - Kerkel, K. A1 - Oshiniwo, J. A1 - Forchel, Alfred T1 - Characterization of lateral semiconductor nano structures by means of x-ray grazing-incidence diffraction Y1 - 1997 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald A1 - Barberka, Thomas Andreas A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig A1 - Hodge, P. A1 - Tredgold, Richard H. T1 - In-plane structure of perfluorotetra decanoic acid Langmuir-Blodgett films and films formed by vacuum deposition Y1 - 1995 ER - TY - JOUR A1 - Stumpe, Joachim A1 - Geue, Thomas A1 - Fischer, Thomas M. A1 - Menzel, Henning T1 - Photochemically induced changes of structures in LB-multilayers of amphotropic polymers Y1 - 1995 ER - TY - JOUR A1 - Pietsch, Ullrich A1 - Barberka, Thomas Andreas A1 - Geue, Thomas A1 - Stömmer, Ralph T1 - X-ray scattering from thin organic films and multilayers Y1 - 1997 ER - TY - JOUR A1 - Eichhorn, Holger A1 - Bruce, Duncan W. A1 - Guillon, D. A1 - Gallani, Jean Louis A1 - Fischer, Thomas A1 - Stumpe, Joachim A1 - Geue, Thomas T1 - Metal ion mediated mesomorphism and thin film behaviour of amphitropic tetraazaporphyrin complexes Y1 - 2001 ER - TY - JOUR A1 - Schwarz, Guntram A1 - Sievers, Torsten K. A1 - Bodenthin, Yves A1 - Hasslauer, Ires A1 - Geue, Thomas A1 - Koetz, Joachim A1 - Kurth, Dirk G. T1 - The structure of metallo-supramolecular polyelectrolytes in solution and on surfaces N2 - Metal ion induced self-assembly of the rigid ligand 1,4-bis(2,2':6',2 ''-terpyridine- 4'-yl) benzene (1) with Fe(II), Co(II), Ni(II) and Zn(II) acetate in aqueous solution results in extended, rigid- rod like metallosupramolecular coordination polyelectrolytes (MEPE-1). Under the current experimental conditions the molar masses range from 1000 g mol(-1) up to 500 000 g mol(-1). The molar mass depends on concentration, stoichiometry, metal-ion and time. In addition, we present viscosity measurements, small angle neutron scattering and AFM data. We introduce a protocol to precisely control the stoichiometry during self-assembly using conductometry. The protocol can be used with different terpyridine ligands and the above-mentioned metal ions and is of paramount importance to obtain meaningful and reproducible results. As a control experiment we studied the mononuclear 4'- (phenyl)2,2':6',2 ''-terpyridine (3) complex with Ni(II) and Zn(II) and the flexible ligand 1,3- bis[4'-oxa(2,2': 6',2 ''-terpyridinyl)] propane (2) with Ni(II) acetate (Ni-MEPE-2). This ligand does not form extended macroassemblies but likely ring-like structures with 3 to 4 repeat units. Through spin- coating of Ni-MEPE-1 on a solid surface we can image the MEPEs in real space by AFM. SANS measurements of Fe-MEPE-1 verify the extended rigid-rod type structure of the MEPEs in aqueous solution. Y1 - 2010 UR - http://pubs.rsc.org/en/content/articlehtml/2010/jm/b926783b U6 - https://doi.org/10.1039/B926783b SN - 0959-9428 ER - TY - JOUR A1 - Schwarz, Guntram A1 - Bodenthin, Yves A1 - Geue, Thomas A1 - Koetz, Joachim A1 - Kurth, Dirk G. T1 - Structure and properties of dynamic rigid rod-like metallo-supramolecular polyelectrolytes in solution N2 - Metal-ion-induced self-assembly in aqueous solution of the rigid ligand 1,4-bis(2,2':6',2 ''-terpyridine-4'-yl)benzene (1) with Fe(OAc)(2) and Ni(OAc)(2) is investigated with viscosimetry, SANS, and AFM. Ligand 1 forms extended, rigid-rod like metallo-supramolecular coordination polyeectrolytes (MEPEs) with a molar mass of up to 200 000 g mol(-1) under the Current experimental conditions. The molar mass depends oil concentration, stoichiometry, and time. By spin-coating MEPEs oil a solid surface, we call image the MEPEs in real space by AFM. Both AFM and SANS confirm the extended rigid-rod-type structure of the MEPEs. As a control experiment, we also studied the flexible ligand 1,3-bis[4'-oxa(2,2':6',2 ''-terpyridinyl)]propane (2). Ligand 2 does not form extended macro-assemblies but likely ringlike structures with three 10 four repeat units. Finally, we present it protocol to control the stoichiometry during self-assembly using conductometry, which is of paramount importance to obtain meaningful and reproducible results. Y1 - 2010 UR - http://pubs.acs.org/doi/full/10.1021/ma902057f U6 - https://doi.org/10.1021/Ma902057f SN - 0024-9297 ER - TY - JOUR A1 - Pietsch, Ullrich A1 - Bodenthin, Yves A1 - Grenzer, Jörg A1 - Geue, Thomas A1 - Möhwald, Helmuth A1 - Kurth, Dirk G. T1 - Structure and temperature behavior of metallo-supramolecular assemblies N2 - A detailed structural analysis of a Langmuir-Blodgett (LB) multilayer composed of a polyelectrolyte-amphiphile complex (PAC) is presented. The PAC is self-assembled from metal ions, ditopic bis-terpyridines, and amphiphiles. The vertical structure of the LB multilayer is investigated by X-ray reflectometry. The multilayer has a periodicity of 57 A, which corresponds to an architecture of flat lying metallo-supramolecular coordination polyelectrolyte (MEPE) rods and upright-standing amphiphiles (dihexadecyl phosphate, DHP). In-plane diffraction reveals hexagonal packing of the DHP molecules. Using extended X-ray absorption fine structure (EXAFS) experiments, we prove that the central metal ion is coordinated to the terpyridine moieties in a pseudo-octahedral coordination environment. The Fe-N bond distances are 1.82 and 2.0 angstrom, respectively. Temperature resolved measurements indicate a reversible phase transition in a temperature range up to 55 degrees C. EXAFS measurements indicate a lengthening of the average Fe-N bond distance from 1.91 to 1.95 angstrom. The widening of the coordination cage upon heating is expected to lower the ligand field stabilization, thus giving rise to spin transitions in these composite materials Y1 - 2005 ER - TY - JOUR A1 - Pietsch, Ullrich A1 - Bhattacharya, M. K. A1 - Sanyal, M. K. A1 - Geue, Thomas T1 - Glass transition in Ultrathin Polymer Films : a Thermal Expansion Study N2 - The glass transition process gets affected in ultrathin films having thickness comparable to the size of the molecules. We observe systematic broadening of the glass transition temperature (T-g) as the thickness of an ultrathin polymer film reduces below the radius of gyration but the change in the average T-g was found to be very small. The existence of reversible negative and positive thermal expansion below and above T-g increased the sensitivity of our thickness measurements performed using energy-dispersive x-ray reflectivity. A simple model of the T-g variation as a function of depth expected from sliding motion could explain the results Y1 - 2005 ER -