Highly Twisted Fenestrindane‐Based Porous Nanographenes.

Two fenestrindane‐based porous nanographenes containing four polyaromatic macrocycles in a highly twisted, basically <italic>S</italic>4–symmetric conformation were synthesized and characterized by NMR spectroscopy and mass spectrometry. Stepwise π‐extension at the periphery of the fenestrindane core by a sequence of eightfold Suzuki‐Miyaura cross‐coupling, fourfold Scholl cyclodehydrogenation and another eightfold Suzuki‐Miyaura reaction affords the porous nanographene precursors in good yields. In the last step, fourfold intramolecular Yamamoto coupling generates the porous nanographenes in 17‐18 %‐yield. Their optical and electronic properties were studied by UV/Vis and fluorescence spectroscopy and cyclic voltammetry. DFT calculations revealed structural details of the macrocycles. The surprisingly weak binding of these porous structures with chloride ions (<italic>K</italic>≈10 M−1) is attributed to their highly twisted conformation. The title compounds represent the first porous nanographenes based on the [5.5.5.5]fenestrane motif and, at the same time, they consist of a fenestrane‐like polyarylene network. [ABSTRACT FROM AUTHOR]