Stacked antiaromaticity in the ??congested space between the aromatic rings in the anthracene dimer

Substance containing two ?-congested aromatic systems are attractive targets in synthetic studies as well efforts designed to explore the unique properties that originate from ?-congestion. Since time of computational by Schleyer and Warner, concept stacked aromaticity created encounter antiaromatic rings has received much attention. A structure ?-congestion between norcorrole was prepared Shinokubo et. al. In contrast, questions about what happens when closely have remained unanswered. Specifically, electronic consequences stacking ?-conjugated not been fully evaluated. To best our knowledge, only one study performed Herges, results which suggest [2.2]paracyclophane, possessing short distance (<3.00 Å) ring planes, a paratropic current benzene rings. This observation is consistent with conclusion antiaromaticity exists within space Herein, we investigated highly anthracene dimers using anthracenophane, possesses inter-plane carbon-carbon ca. 2.80 Å. The absorption spectrum this substance contains weak broad band 450 550 nm attributed HOMO-LUMO transition. These exist planar cyclooctatetraene derivatives having 8?-electron antiaromaticity. nucleus-independent chemical shift anisotropy induced density calculations indicate relatively character central six-membered moieties anthracenophane. addition, an attempt enhance anthracenophane pressure unsuccessful.