@article{IvanovaKoesterHolsteinetal.2021,
  author    = {Ivanova, Svetlana and K{\"o}ster, Eva and Holstein, Julian J. and Keller, Niklas and Clever, Guido H. and Bein, Thomas and Beuerle, Florian},
  title     = {Isoreticular crystallization of highly porous cubic covalent organic cage compounds},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {32},
  doi       = {10.1002/anie.202102982},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256462},
  pages     = {17455-17463},
  year      = {2021},
  abstract  = {Modular frameworks featuring well-defined pore structures in microscale domains establish tailor-made porous materials. For open molecular solids however, maintaining long-range order after desolvation is inherently challenging, since packing is usually governed by only a few supramolecular interactions. Here we report on two series of nanocubes obtained by co-condensation of two different hexahydroxy tribenzotriquinacenes (TBTQs) and benzene-1,4-diboronic acids (BDBAs) with varying linear alkyl chains in 2,5-position. n-Butyl groups at the apical position of the TBTQ vertices yielded soluble model compounds, which were analyzed by mass spectrometry and NMR spectroscopy. In contrast, methyl-substituted cages spontaneously crystallized as isostructural and highly porous solids with BET surface areas and pore volumes of up to 3426 m\(^2\) g\(^{-1}\) and 1.84 cm\(^3\) g\(^{-1}\). Single crystal X-ray diffraction and sorption measurements revealed an intricate cubic arrangement of alternating micro- and mesopores in the range of 0.97-2.2 nm that are fine-tuned by the alkyl substituents at the BDBA linker.},
  language  = {en}
}
@article{RagerJakowetzGoleetal.2019,
  author    = {Rager, Sabrina and Jakowetz, Andreas C. and Gole, Bappaditya and Beuerle, Florian and Medina, Dana D. and Bein, Thomas},
  title     = {Scaffold-Induced Diketopyrrolopyrrole Molecular Stacks in a Covalent Organic Framework},
  series = {Chemistry of Materials},
  volume    = {31},
  journal   = {Chemistry of Materials},
  number    = {8},
  doi       = {10.1021/acs.chemmater.8b02882},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224927},
  pages     = {2707-2712},
  year      = {2019},
  abstract  = {In recent years, covalent organic frameworks (COFs) have attracted considerable attention due to their crystalline and porous nature, which positions them as intriguing candidates for diverse applications such as catalysis, sensing, or optoelectronics. The incorporation of dyes or semiconducting moieties into a rigid two-dimensional COF can offer emergent features such as enhanced light harvesting or charge transport. However, this approach can be challenging when dealing with dye molecules that exhibit a large aromatic backbone, since the steric demand of solubilizing side chains also needs to be integrated into the framework. Here, we report the successful synthesis of DPP2-HHTP-COF consisting of diketopyrrolopyrrole (DPP) diboronic acid and hexahydroxytriphenylene (HHTP) building blocks. The well-known boronate ester coupling motif guides the formation of a planar and rigid backbone and long-range molecular DPP stacks, resulting in a highly crystalline and porous material. DPP2-HHTP-COF exhibits excellent optical properties including strong absorption over the visible spectral range, broad emission into the NIR and a singlet lifetime of over 5 ns attributed to the formation of molecular stacks with J-type interactions between the DPP subcomponents in the COF. Electrical measurements of crystalline DPP2-HHTP-COF pellets revealed conductivity values of up to 10(-6) S cm(-1).},
  language  = {en}
}