TY  - JOUR
A1  - Okatova, Olga V.
A1  - Andreeva, Katharina A.
A1  - Schulz, Burkhard
A1  - Lavrenko, Peter N.
T1  - Degradation of poly(m-phenylene oxadiazole) in concentrated sulfuric acid
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Okatova, Olga V.
A1  - Schulz, Burkhard
A1  - Andreeva, Katharina A.
A1  - Strelina, Irina A.
T1  - Hydrodynamic and dynamo-optical properties of poly(1,3-phenylene-1,3,4-oxadiazole) molecules in sulphuric acid
N2  - Translational diffusion of the macromolecules, intrinsic viscosity and flow birefringence induced in dilute solutions of poly(1,3-phenylene-1,3,4-oxadiazole) (PMOD) in conc. sulphuric acid has been investigated. Molecular-weight dependences of hydrodynamic and dynamo-optical properties are established over the M range from 8.1  103 to 87  103. Experimental data agree well with the theories developed for translational friction and intrinsic viscosity of the wormlike chains with the following molecular parameters: mass per chain unit ML = 22.7 Dalton/Å, the Kuhn segment length A = 59 ± 4 Å, the chain diameter d = 4 ± 1.5 Å. Hindrance to intramolecular rotation is characterized by the parameter s = 1.7. The shear optical coefficient was found to be approximately 1.7 times lower the value of that obtained in the same solvent for the para-phenylene isomer of this polymer, being in good agreement with higher equilibrium flexibility of the PMOD molecule chains in solutions as determined herein from the hydrodynamic data.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Freydank, Anke-Christine
A1  - Helms, Andreas
A1  - Geue, Thomas
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
A1  - Stiller, Burkhard
A1  - Knochenhauer, Gerald
T1  - Vacuum deposition films of oxadiazole compounds : formation and structure investigation
N2  - The search for alternative routes of organic thin film formation is stimulated by the outstanding properties of these films in such fields as nonlinear optics, photonic data processing and molecular electronics. The formation of highly ordered multilayer structures by thermal vacuum deposition (VD) of organic compounds is an essential step toward the application of supramolecular organic architectures in technical systems. The VD of an amphiphilic substituted 2,5- diphenylene-1,3,4-oxadiazole 1 onto silicon substrates at defined temperature was used for the formation of ultrathin films. The structural data obtained for the VD-films of oxadiazole 1 by means of X-ray reflectivity, X-ray grazing incidence diffraction and atomic force microscopy (AFM) investigations indicate the formation of well ordered oxadiazole multilayers. The structure of the VD-multilayers is compared with that of Langmuir-Blodgett (LB) films and thermally treated LB-multilayers prepared from the same compound.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Andreeva, Katharina A.
A1  - Strelina, Irina A.
A1  - Garmonova, Tatjana I.
A1  - Schulz, Burkhard
T1  - Optical anisotropy and flexibility of poly(m-phenylene oxadiazole) in sulfuric acid
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Orgzall, Ingo
A1  - Lorenz, Bernd
A1  - Mikat, Jürgen E. R.
A1  - Reck, Günter
A1  - Knochenhauer, Gerald
A1  - Schulz, Burkhard
T1  - Phase transition in 1,3,4-oxadiazole crystals under high pressure
N2  - Crystalline 2,5-di(4-nitrophenyl)-1,3,4-oxadiazole (DNO) has been investigated at pressures up to 5 GPa using Raman and optical spectroscopy as well as energy dispersive X-ray techniques. At ambient pressure DNO shows an orthorhombic unit cell (a = 0.5448 nm, b = 1.2758 nm, c = 1.9720 nm, density 1.513 g cm-3) with an appropriate space group Pbcn. From Raman spectroscopic investigations three phase transitions have been detected at 0.88, 1.28, and 2.2 GPa, respectively. These transitions have also been confirmed by absorption spectroscopy and X-ray measurements. Molecular modeling simulations have considerably contributed to the interpretation of the X-ray diffractograms. In general, the nearly flat structure of the oxadiazole molecule is preserved during the transitions. All subsequent structures are characterized by a stack-like arrangement of the DNO molecules. Only the mutual position of these molecular stacks changes due to the transformations so that this process may be described as a topotactical reaction. Phases II and III show a monoclinic symmetry with space group P21/c with cell parameters a = 1.990 nm, b = 0.500 nm, c = 1.240 nm, ß = 91.7°, density 1.681 g cm-3 (phase II, determined at 1. 1 GPa) and a = 1.890 nm, b = 0.510 nm, C = 1.242 nm, ß = 89.0°, density 1.733 g cm-3 (phase 111, determined at 2.0 GPa), respectively. The high-pressure phase IV stable at least up to 5 GPa shows again an orthorhombic structure with space group Pccn with corresponding cell parameters at 2.9 GPa: a = 0.465 nm, b = 1.920 nm, c = 1.230 nm and density 1.857 g cm-3 . For the first phase a blue pressure shift of the onset of absorption by about 0.032 eV GPa has been observed that may be explained by pressure influences on the electronic conjugation of the molecule. In the intermediate and high-pressure phases II-IV the onset of absorption shifts to increased wavelengths due to larger intermolecular interactions and enhanced excitation delocalization with decreasing intermolecular spacing.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Schürmann, H.
A1  - Koch, Norbert
A1  - Imperia, Paolo
A1  - Schrader, Sigurd
A1  - Jandke, M.
A1  - Strohriegl, P.
A1  - Schulz, Burkhard
A1  - Leising, G.
A1  - Brehmer, Ludwig
T1  - Ultraviolet photoelectron spectroscopic study of heterocyclic model compounds for electroluminescent devices
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Banks, Jo Ann
A1  - Nishiyama, Tomoaki
A1  - Hasebe, Mitsuyasu
A1  - Bowman, John L.
A1  - Gribskov, Michael
A1  - dePamphilis, Claude
A1  - Albert, Victor A.
A1  - Aono, Naoki
A1  - Aoyama, Tsuyoshi
A1  - Ambrose, Barbara A.
A1  - Ashton, Neil W.
A1  - Axtell, Michael J.
A1  - Barker, Elizabeth
A1  - Barker, Michael S.
A1  - Bennetzen, Jeffrey L.
A1  - Bonawitz, Nicholas D.
A1  - Chapple, Clint
A1  - Cheng, Chaoyang
A1  - Correa, Luiz Gustavo Guedes
A1  - Dacre, Michael
A1  - DeBarry, Jeremy
A1  - Dreyer, Ingo
A1  - Elias, Marek
A1  - Engstrom, Eric M.
A1  - Estelle, Mark
A1  - Feng, Liang
A1  - Finet, Cedric
A1  - Floyd, Sandra K.
A1  - Frommer, Wolf B.
A1  - Fujita, Tomomichi
A1  - Gramzow, Lydia
A1  - Gutensohn, Michael
A1  - Harholt, Jesper
A1  - Hattori, Mitsuru
A1  - Heyl, Alexander
A1  - Hirai, Tadayoshi
A1  - Hiwatashi, Yuji
A1  - Ishikawa, Masaki
A1  - Iwata, Mineko
A1  - Karol, Kenneth G.
A1  - Koehler, Barbara
A1  - Kolukisaoglu, Uener
A1  - Kubo, Minoru
A1  - Kurata, Tetsuya
A1  - Lalonde, Sylvie
A1  - Li, Kejie
A1  - Li, Ying
A1  - Litt, Amy
A1  - Lyons, Eric
A1  - Manning, Gerard
A1  - Maruyama, Takeshi
A1  - Michael, Todd P.
A1  - Mikami, Koji
A1  - Miyazaki, Saori
A1  - Morinaga, Shin-ichi
A1  - Murata, Takashi
A1  - Müller-Röber, Bernd
A1  - Nelson, David R.
A1  - Obara, Mari
A1  - Oguri, Yasuko
A1  - Olmstead, Richard G.
A1  - Onodera, Naoko
A1  - Petersen, Bent Larsen
A1  - Pils, Birgit
A1  - Prigge, Michael
A1  - Rensing, Stefan A.
A1  - Mauricio Riano-Pachon, Diego
A1  - Roberts, Alison W.
A1  - Sato, Yoshikatsu
A1  - Scheller, Henrik Vibe
A1  - Schulz, Burkhard
A1  - Schulz, Christian
A1  - Shakirov, Eugene V.
A1  - Shibagaki, Nakako
A1  - Shinohara, Naoki
A1  - Shippen, Dorothy E.
A1  - Sorensen, Iben
A1  - Sotooka, Ryo
A1  - Sugimoto, Nagisa
A1  - Sugita, Mamoru
A1  - Sumikawa, Naomi
A1  - Tanurdzic, Milos
A1  - Theissen, Guenter
A1  - Ulvskov, Peter
A1  - Wakazuki, Sachiko
A1  - Weng, Jing-Ke
A1  - Willats, William W. G. T.
A1  - Wipf, Daniel
A1  - Wolf, Paul G.
A1  - Yang, Lixing
A1  - Zimmer, Andreas D.
A1  - Zhu, Qihui
A1  - Mitros, Therese
A1  - Hellsten, Uffe
A1  - Loque, Dominique
A1  - Otillar, Robert
A1  - Salamov, Asaf
A1  - Schmutz, Jeremy
A1  - Shapiro, Harris
A1  - Lindquist, Erika
A1  - Lucas, Susan
A1  - Rokhsar, Daniel
A1  - Grigoriev, Igor V.
T1  - The selaginella genome identifies genetic changes associated with the evolution of vascular plants
JF  - Science
N2  - Vascular plants appeared similar to 410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes.
Y1  - 2011
U6  - https://doi.org/10.1126/science.1203810
SN  - 0036-8075
VL  - 332
IS  - 6032
SP  - 960
EP  - 963
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Tanne, Johannes
A1  - Jeoung, Jae-Hun
A1  - Peng, Lei
A1  - Yarman, Aysu
A1  - Dietzel, Birgit
A1  - Schulz, Burkhard
A1  - Schad, Daniel
A1  - Dobbek, Holger
A1  - Wollenberger, Ursula
A1  - Bier, Frank Fabian
A1  - Scheller, Frieder W.
T1  - Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - A nanohybrid consisting of poly(3-aminobenzenesulfonic acid-co-aniline) and multiwalled carbon nanotubes [MWCNT-P(ABS-A)]) on a gold electrode was used to immobilize the hexameric tyrosine-coordinated heme protein (HTHP). The enzyme showed direct electron transfer between the heme group of the protein and the nanostructured surface. Desorption of the noncovalently bound heme from the protein could be excluded by control measurements with adsorbed hemin on aminohexanthiol-modified electrodes. The nanostructuring and the optimised charge characteristics resulted in a higher protein coverage as compared with MUA/MU modified electrodes. The adsorbed enzyme shows catalytic activity for the cathodic H2O2 reduction and oxidation of NADH.
KW  - HTHP
KW  - Nanohybrid
KW  - Poylaniline
KW  - Multiwalled carbon nanotube
Y1  - 2015
U6  - https://doi.org/10.1002/elan.201500231
SN  - 1040-0397
SN  - 1521-4109
VL  - 27
IS  - 10
SP  - 2262
EP  - 2267
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Machatschek, Rainhard Gabriel
A1  - Schöne, Anne-Christin
A1  - Raschdorf, Elisa
A1  - Ihlenburg, Ramona
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Interfacial properties of morpholine-2,5-dione-based oligodepsipeptides and multiblock copolymers
JF  - MRS Communications
N2  - Oligodepsipeptides (ODPs) with alternating amide and ester bonds prepared by ring-opening polymerization of morpholine-2,5-dione derivatives are promising matrices for drug delivery systems and building blocks for multifunctional biomaterials. Here, we elucidate the behavior of three telechelic ODPs and one multiblock copolymer containing ODP blocks at the air-water interface. Surprisingly, whereas the oligomers and multiblock copolymers crystallize in bulk, no crystallization is observed at the air-water interface. Furthermore, polarization modulation infrared reflection absorption spectroscopy is used to elucidate hydrogen bonding and secondary structures in ODP monolayers. The results will direct the development of the next ODP-based biomaterial generation with tailored properties for highly sophisticated applications.
Y1  - 2019
U6  - https://doi.org/10.1557/mrc.2019.21
SN  - 2159-6859
SN  - 2159-6867
VL  - 9
IS  - 1
SP  - 170
EP  - 180
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Karageorgiev, Peter
A1  - Neher, Dieter
A1  - Schulz, Burkhard
A1  - Stiller, Burkhard
A1  - Pietsch, Ullrich
A1  - Giersig, Michael
A1  - Brehmer, Ludwig
T1  - From anisotropic photo-fluidity towards nanomanipulation in the optical near-field
N2  - An increase in random molecular vibrations of a solid owing to heating above the melting point leads to a decrease in its long-range order and a loss of structural symmetry. Therefore conventional liquids are isotropic media. Here we report on a light-induced isothermal transition of a polymer film from an isotropic solid to an anisotropic liquid state in which the degree of mechanical anisotropy can be controlled by light. Whereas during irradiation by circular polarized light the film behaves as an isotropic viscoelastic fluid, it shows considerable fluidity only in the direction parallel to the light field vector under linear polarized light. The fluidization phenomenon is related to photoinduced motion of azobenzene-functionalized molecular units, which can be effectively activated only when their transition dipole moments are oriented close to the direction of the light polarization. We also describe here how the photofluidization allows nanoscopic elements of matter to be precisely manipulated
Y1  - 2005
SN  - 1476-1122
ER  -