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A three‐component synthesis methodology is described for the formation of covalent organic frameworks (COFs) containing extended aromatics. Notably, this approach enables synthesis of the building blocks and COF along parallel reaction landscapes, on a similar timeframe. The use of fragmental building block components, namely pyrene dione diboronic acid as aggregation‐inducing COF precursor and the diamines o‐phenylenediamine (Ph), 2,3‐diaminonaphthalene (Naph), or (1R,2R)‐(+)‐1,2‐diphenylethylenediamine (2Ph) as extending functionalization units in conjunction with 2,3,6,7,10,11‐hexahydroxytriphenylene, resulted in the formation of the corresponding pyrene‐fused azaacene, i.e. Aza‐COF series with full conversion of the dione moiety, long‐range order, and high surface area. In addition, the novel three‐component synthesis was successfully applied to produce highly crystalline, oriented thin films of the Aza‐COFs with nanostructured surfaces on various substrates. The Aza‐COFs exhibit light absorption maxima in the blue spectral region, and each Aza‐COF presents a distinct photoluminescence profile. Transient absorption measurements of Aza‐Ph‐ and Aza‐Naph‐COFs suggest ultrafast relaxation dynamics of excited‐states within these COFs. [ABSTRACT FROM AUTHOR]

Singlet 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. [ABSTRACT FROM AUTHOR]

In this contribution, we focused on integrating a phenylene-bridged dibenzodiazahexacene dimer ( o -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/ o -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 o -DAD. Fluorescence spectroscopy prompted an energy transfer between the individual constituents, a conclusion that was exclusively derived from the quenching of the o -DAD-centered fluorescence. Excitation spectroscopy with a focus on the SWCNT fluorescence confirmed independently this conclusion by showing o -DAD-centered features. Our work was rounded off by time-resolved transient absorption measurements with SWCNT/ o -DAD, in which evidence was gathered for the sequential o -DAD-centered SF with an efficiency of 112% followed by a unidirectional energy transfer from o -DAD to SWCNT and a rapid deactivation. The energy transfer efficiency from SF products such as (S 1 S 0 ) CT and 1 (T 1 T 1 ) exceeded the 100% threshold with values of 115%, which is conventionally found in energy transfer schemes.