Metal Phthalocyanine-Fullerene Dyads: Promising Lamellar Columnar Donor-Acceptor Liquid Crystal Phases

Liquid crystal (LC) shape-amphiphiles with a disc tethered to a fullerene have been intensely studied for the application in photovoltaics, and helical nanosegregation of C₆₀ has been claimed around the π-stacking disks based on X-ray results. The most promising materials reported to date have been resynthesized and studied comprehensively by XRS, density measurements, modelling, and electron density reconstruction. In contrast to previous reports, the results indicate that metal phthalocyanine-fullerene mesogens pack in lamellar columnar phases with p2gm symmetry. Fullerenes assemble in layers and are flanked by phthalocyanine columns, thus explaining the balanced charge carrier mobility of electrons and holes. Such variable donor-acceptor structures are promising for organic electronic applications.