TY - JOUR A1 - Janietz, Dietmar A1 - Katholy, Stefan A1 - Dietzel, Birgit A1 - Brehmer, Ludwig T1 - Monolayer behaviour of two-fold hydroxy terminated sheet-like Tetrakis(phenylethynyl) benzene derivatives Y1 - 1997 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Katholy, Stefan A1 - Brehmer, Ludwig T1 - Monolayer properties of Amphiphilic Tetrakis(phenylethynyl)benzene compounds Y1 - 1998 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Hofmann, Dieter A1 - Reiche, Jürgen T1 - Molecular organization of amphiphilic disc-shaped penta-alkynes in LB-mono- and multilayers N2 - Amphiphilic disc-shaped penta-alkynes were studied with regard to their molecular organization in Langmuir-Blod- gett (LB) mono- and multilayers. It was found that each compound investigated forms edge-on arranged stable monolayers at the air-water interface. LB-multilayers derived from fivefold pentyl-substituted pentaynes are characterized by an edge-on ordering of the molecules within Y-type bilayers. One of these compounds, containing a hydoxy substituent as hydrophilic head group, is exemplified and two possible rectangular molecular assemblies perpendicular to the substrate, each with a columnar in-plane packing, will be discussed as a result of molecular modelling. Based on the experimental results, hexagonal layer packing in the LB-film of a disc-shaped penta-alkynyl carboxylic acid without lateral substituents proved to be possible, which, furthermore, could be confirmed by molecular mechanics simulation. Y1 - 1994 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Hofmann, Dieter A1 - Reiche, Jürgen T1 - Reply to comment on "Molecular organization of amphiphilic disc-shaped penta-alkynes in LB mono- and multilayers" N2 - The model for the Langmuir-Blodgett (LB) film structure of amphiphilic disc-shaped penta-alkynes is refined. It is shown that LB experiments reported in a comment on one of our papers do not contradict the molecular organization within the LB films of the penta-alkynes we proposed. Y1 - 1995 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Festag, R. A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Amphotropic oligomeric 1,3,5-triazines containing disc-shaped pentaalkyne and triphenylene side groups Y1 - 1996 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Festag, R. A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Supramolecular assemblies of new amphotropic oligomers with disc-shaped side groups Y1 - 1995 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Festag, R. A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Self-organization of new oligomers containing disc-shaped side groups Y1 - 1994 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Festag, R. A1 - Schmidt, C. A1 - Tsukruk, V. V. A1 - Wendorff, Joachim Heinz T1 - Interfacial behaviour and thermal properties of triazine modified triphenylene oligomers Y1 - 1995 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Ahuja, Rajeev C. A1 - Möbius, Dietmar T1 - Langmuir monolayers of sheet-shaped multialkyne amphiphiles Y1 - 1997 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Ahuja, Rajeev C. A1 - Möbius, Dietmar T1 - Monomeric and oligomeric discotic amphiphiles at the air : water interface Y1 - 1994 ER - TY - JOUR A1 - Janietz, Dietmar T1 - Structure formation of functional sheet-shaped mesogens Y1 - 1998 ER - TY - JOUR A1 - Janietz, Dietmar T1 - Covalently linked donor-acceptor mesogens based on disc-shaped penta-alkynes Y1 - 1996 ER - TY - JOUR A1 - Janietz, Dietmar T1 - Neue discotische Amphiphile : Strukturbildung durch Formanisotropie und Funktionalisierung Y1 - 1995 ER - TY - JOUR A1 - Janietz, Dietmar T1 - Structure formation of new triazine modified amphotropic discotics : light on organized molecular systems Y1 - 1995 ER - TY - JOUR A1 - Inal, Sahika A1 - Kölsch, Jonas D. A1 - Chiappisi, Leonardo A1 - Janietz, Dietmar A1 - Gradzielski, Michael A1 - Laschewsky, André A1 - Neher, Dieter T1 - Structure-related differences in the temperature-regulated fluorescence response of LCST type polymers N2 - We demonstrate new fluorophore-labelled materials based on acrylamide and on oligo(ethylene glycol) (OEG) bearing thermoresponsive polymers for sensing purposes and investigate their thermally induced solubility transitions. It is found that the emission properties of the polarity-sensitive (solvatochromic) naphthalimide derivative attached to three different thermoresponsive polymers are highly specific to the exact chemical structure of the macromolecule. While the dye emits very weakly below the LCST when incorporated into poly(N-isopropylacrylamide) (pNIPAm) or into a polyacrylate backbone bearing only short OEG side chains, it is strongly emissive in polymethacrylates with longer OEG side chains. Heating of the aqueous solutions above their cloud point provokes an abrupt increase of the fluorescence intensity of the labelled pNIPAm, whereas the emission properties of the dye are rather unaffected as OEG-based polyacrylates and methacrylates undergo phase transition. Correlated with laser light scattering studies, these findings are ascribed to the different degrees of pre-aggregation of the chains at low temperatures and to the extent of dehydration that the phase transition evokes. It is concluded that although the temperature-triggered changes in the macroscopic absorption characteristics, related to large-scale alterations of the polymer chain conformation and aggregation, are well detectable and similar for these LCST-type polymers, the micro-environment provided to the dye within each polymer network differs substantially. Considering sensing applications, this finding is of great importance since the temperature-regulated fluorescence response of the polymer depends more on the macromolecular architecture than the type of reporter fluorophore. Y1 - 2013 UR - http://pubs.rsc.org/en/content/articlepdf/2013/tc/c3tc31304b U6 - https://doi.org/10.1039/C3TC31304B ER - TY - JOUR A1 - Inal, Sahika A1 - Koelsch, Jonas D. A1 - Chiappisi, Leonardo A1 - Kraft, Mario A1 - Gutacker, Andrea A1 - Janietz, Dietmar A1 - Scherf, Ullrich A1 - Gradzielski, Michael A1 - Laschewsky, André A1 - Neher, Dieter T1 - Temperature-Regulated Fluorescence Characteristics of Supramolecular Assemblies Formed By a Smart Polymer and a Conjugated Polyelectrolyte JF - MACROMOLECULAR CHEMISTRY AND PHYSICS N2 - Aqueous mixtures of a coumarin-labeled non-ionic thermoresponsive copolymer and a cationic polythiophene exhibit marked changes in their fluorescence properties upon heating. At room temperature, emission from the label is significantly quenched due to energy transfer to the conjugated polyelectrolyte. Heating the mixture reduces the energy-transfer efficiency markedly, resulting in a clearly visible change of the emission color. Although the two macromolecules associate strongly at room temperature, the number of interacting sites is largely reduced upon the phase transition. Crucially, the intermolecular association does not suppress the responsiveness of the smart polymer, meaning that this concept should be applicable to chemo- or bioresponsive polymers with optical read-out, for example, as a sensor device. KW - aqueous solutions KW - conjugated polyelectrolytes KW - fluorescence (or Forster) KW - resonance energy transfer KW - phase transitions KW - thermoresponsive polymers Y1 - 2013 U6 - https://doi.org/10.1002/macp.201200493 SN - 1022-1352 VL - 214 IS - 4 SP - 435 EP - 445 PB - WILEY-V C H VERLAG GMBH CY - WEINHEIM ER - TY - JOUR A1 - Inal, Sahika A1 - Koelsch, Jonas D. A1 - Chiappisi, Leonardo A1 - Janietz, Dietmar A1 - Gradzielski, Michael A1 - Laschewsky, André A1 - Neher, Dieter T1 - Structure-related differences in the temperature-regulated fluorescence response of LCST type polymers JF - Journal of materials chemistry : C, Materials for optical and electronic devices N2 - We demonstrate new fluorophore-labelled materials based on acrylamide and on oligo(ethylene glycol) (OEG) bearing thermoresponsive polymers for sensing purposes and investigate their thermally induced solubility transitions. It is found that the emission properties of the polarity-sensitive (solvatochromic) naphthalimide derivative attached to three different thermoresponsive polymers are highly specific to the exact chemical structure of the macromolecule. While the dye emits very weakly below the LCST when incorporated into poly(N-isopropylacrylamide) (pNIPAm) or into a polyacrylate backbone bearing only short OEG side chains, it is strongly emissive in polymethacrylates with longer OEG side chains. Heating of the aqueous solutions above their cloud point provokes an abrupt increase of the fluorescence intensity of the labelled pNIPAm, whereas the emission properties of the dye are rather unaffected as OEG-based polyacrylates and methacrylates undergo phase transition. Correlated with laser light scattering studies, these findings are ascribed to the different degrees of pre-aggregation of the chains at low temperatures and to the extent of dehydration that the phase transition evokes. It is concluded that although the temperature-triggered changes in the macroscopic absorption characteristics, related to large-scale alterations of the polymer chain conformation and aggregation, are well detectable and similar for these LCST-type polymers, the micro-environment provided to the dye within each polymer network differs substantially. Considering sensing applications, this finding is of great importance since the temperature-regulated fluorescence response of the polymer depends more on the macromolecular architecture than the type of reporter fluorophore. Y1 - 2013 U6 - https://doi.org/10.1039/c3tc31304b SN - 2050-7526 VL - 1 IS - 40 SP - 6603 EP - 6612 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Goldmann, Daniela A1 - Nordsieck, A. A1 - Janietz, Dietmar A1 - Frese, T. A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Smectic and columnar liquid crystalline phases through charge-transfer interactions N2 - New heterocyclic electron donors based on. a 1,3,5-triazine nucleus are presented. Three phenyl rings are grafted to the triazine core either via secondary amino groups or by a direct C,C-linkage and a specific number of decyloxy chains is attached to the molecular periphery. The compounds are non-liquid crystalline in their pure states. Lamellar or columnar mesophases are induced by attractive interactions with electron acceptors Y1 - 2004 SN - 1058-725X ER - TY - JOUR A1 - Goldmann, Daniela A1 - Mahlstedt, S. A1 - Janietz, Dietmar A1 - Busch, P. A1 - Schmidt, C. A1 - Stracke, A. A1 - Wendorff, Joachim Heinz T1 - Mesomorphic donor-acceptor twin molecules with covalently linked sheet-like pentaalkyne and nitrofluorenone subunits Y1 - 1998 ER - TY - JOUR A1 - Goldmann, Daniela A1 - Janietz, Dietmar A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Columnar liquid crystalline phases through hydrogen bonding and nanoscale segregation N2 - Two columnar phases forming 2,4,6-triarylamino-1,3,5-triazines have been investigated in binary mixtures with calamitic and non-liquid crystalline benzoic acids carrying one or two alkoxy chains at the aromatic core. The triazines form hydrogen bonded aggregates with the complementary acids. Each investigated equimolar mixture exhibits a columnar mesophase due to segregation of the H-bonded polar core region from the lipophilic aliphatic molecular segments. The cross sectional shape of cylindrical aggregates and, therefore, the two-dimensional lattice symmetries, hexagonal or rectangular, are defined by the number of alkoxy chains of the benzoic acid component Y1 - 2004 SN - 0959-9428 ER -