A Star-shaped Oligo(phenylenevinylene) Liquid Crystal Host with an Anthracene Guest-A Double Nanosegregating Supermesogen.
Hexasubstituted C3-symmetric benzenes with three elongated shape-persistent oligo(phenylenevinylene) arms and three pyridyl hydrogen-bond acceptors have been synthesized. These mesogens assemble in a double-helical columnar liquid crystal (LC) structure, owing to the compensation of free spaces between conjugated arms by dimer formation. The void is filled also by up to three anthracene carboxylic acids as guests forming hydrogen bonded supermesogens assembling in columnar LC and soft-crystal phases. Thin film fluorescence and solid-state NMR spectroscopy imply a transition from a disordered columnar LC to an unexpected double nanosegregated morphology of a filled soft columnar crystal phase. An additional intracolumnar separation of anthracene and oligo(phenylenevinylene) chromophores occurs, separate to the general segregation of aliphatic and aromatic building blocks in LC structures. The new type of supermesogens will enable the rational design of host-guest double cables with a wide range of different conjugated building blocks.
Institute of Organic Chemistry & Center for Nanosystems Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Philipp
P
Maier
Institute of Organic Chemistry & Center for Nanosystems Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Matthias
M
Grüne
Institute of Organic Chemistry & Center for Nanosystems Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Matthias
M
Lehmann
double cable; host-guest systems; liquid crystals; nanosegregation; supermesogens