@article{GoleStepanenkoRageretal.2018, author = {Gole, Bappaditya and Stepanenko, Vladimir and Rager, Sabrina and Gr{\"u}ne, Matthias and Medina, Dana D. and Bein, Thomas and W{\"u}rthner, Frank and Beuerle, Florian}, title = {Microtubular Self-Assembly of Covalent Organic Frameworks}, series = {Angewandte Chemie International Edition}, volume = {57}, journal = {Angewandte Chemie International Edition}, doi = {10.1002/anie.201708526}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227373}, pages = {846-850}, year = {2018}, abstract = {Despite significant progress in the synthesis of covalent organic frameworks (COFs), reports on the precise construction of template-free nano- and microstructures of such materials have been rare. In the quest for dye-containing porous materials, a novel conjugated framework DPP-TAPP-COF with an enhanced absorption capability up to λ=800 nm has been synthesized by utilizing reversible imine condensations between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) and a diketopyrrolopyrrole (DPP) dialdehyde derivative. Surprisingly, the obtained COF exhibited spontaneous aggregation into hollow microtubular assemblies with outer and inner tube diameters of around 300 and 90 nm, respectively. A detailed mechanistic investigation revealed the time-dependent transformation of initial sheet-like agglomerates into the tubular microstructures.}, language = {en} } @article{SanchezNayaStepanenkoMandeletal.2021, author = {Sanchez-Naya, Roberto and Stepanenko, Vladimir and Mandel, Karl and Beuerle, Florian}, title = {Modulation of Crystallinity and Optical Properties in Composite Materials Combining Iron Oxide Nanoparticles and Dye-Containing Covalent Organic Frameworks}, series = {Organic Materials}, volume = {3}, journal = {Organic Materials}, doi = {10.1055/s-0040-1722655}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231480}, pages = {17-24}, year = {2021}, abstract = {Two series of organic-inorganic composite materials were synthesized through solvothermal imine condensation between diketopyrrolopyrrole dialdehyde DPP-1 and 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) in the presence of varying amounts of either amino- or carboxy-functionalized superparamagnetic iron oxide nanoparticles (FeO). Whereas high FeO loading induced cross-linking of the inorganic nanoparticles by amorphous imine polymers, a lower FeO content resulted in the formation of crystalline covalent organic framework domains. All hybrid materials were analyzed by magnetization measurements, powder X-ray diffraction, electron microscopy, IR, and UV/Vis absorption spectroscopy. Crystallinity, chromophore stacking, and visible absorption features are directly correlated to the mass fraction of the components, thus allowing for a fine-tuning of materials properties.}, language = {en} }