We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C and C , with remarkably large binding constants (ca. 10 M ), as estimated by fluorescence measurements.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2022
We present the first helicene carbon nanoohop that integrates a [6]helicene into [7]cycloparaphenylene. The [6]helicene endows the helicene carbon nanohoop with chiroptical properties and configurational stability typical for higher helicenes, while the radially conjugated seven para-phenylenes largely determine the optoelectronic properties. The structure of the helicene carbon nanoohop was unambiguously characterized by NMR, MS and X-ray analysis that revealed that it possesses a topology of a Möbius strip in the solid state and in solution.
View Article and Find Full Text PDFThe chemical processing of low-dimensional carbon nanostructures is crucial for their integration in future devices. Here we apply a new methodology in atomically precise engineering by combining multistep solution synthesis of N-doped molecular graphene nanoribbons (GNRs) with mass-selected ultra-high vacuum electrospray controlled ion beam deposition on surfaces and real-space visualisation by scanning tunnelling microscopy. We demonstrate how this method yields solely a controllable amount of single, otherwise unsublimable, GNRs of 2.
View Article and Find Full Text PDFIn this contribution, we focused on integrating a phenylene-bridged dibenzodiazahexacene dimer (-DAD), which is singlet fission (SF) active, onto single-walled carbon nanotubes (SWCNTs) as a low-energy sink for energetically low lying excited states that stem from SF. Spectroscopic and microscopic assays assisted in documenting that SWCNT/-DAD feature high stability in THF as a result of electronic interactions between the individual constituents. For example, statistical Raman analysis underlined n-doping of SWCNTs in the presence of -DAD.
View Article and Find Full Text PDFA straightforward method for the synthesis of two dibenzo[,]anthracene-5,6,12,13-diquinone building blocks is reported. To showcase their usefulness, a series of dibenzo[,]anthracene nitrogenated derivatives have been synthesized that show different optoelectronic, redox, and charge transport properties, illustrating their potential as organic semiconductors.
View Article and Find Full Text PDFSinglet fission has emerged as a promising strategy to avoid the loss of extra energy through thermalization in solar cells. A family of dimers consisting of nitrogen-doped pyrene-fused acenes that undergo singlet fission with triplet quantum yields as high as 125 % are presented. They provide new perspectives for nitrogenated polycyclic aromatic hydrocarbons and for the design of new materials for singlet fission.
View Article and Find Full Text PDFStar-shaped nanographenes (SNGs) are large monodisperse polycyclic aromatic hydrocarbons that are larger than a nanometer and have shown a lot of promise in a wide range of applications including electronics, energy conversion, and sensing. Herein, we report a new family of giant star-shaped N-doped nanographenes with diameters up to 6.5 nm.
View Article and Find Full Text PDFThe properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N-doped graphene nanoribbons with different lengths.
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