Chiroptical Properties of Planar Benzobisthiazole-Bridged Squaraine Dimers.

Five chiral squaraine dimers were synthesized by fusing chiral indolenine semisquaraines with three different benzobisthiazole bridges. The thereby created squaraine dimers show a strong splitting of the lowest energy absorption bands caused by exciton coupling. The intensities of the two exciton transitions and the energetic splitting depend on the angle of the two squaraine moieties within the chromophore dimer.

Axially chiral indolenine derived chromophore dimers and their chiroptical absorption and emission properties.

Yamamoto homocoupling of two chiral oxindoles led to the atropo-diastereoselective formation of an axially chiral oxindole dimer. This building block served as the starting material for the syntheses of axially chiral squaraine and merocyanine chromophore dimers. These dimers show pronounced chiroptical properties, this is, outstandingly high ECD signals (Δ up to 1500 M cm) as a couplet with positive Cotton effect for the -configuration around the biaryl axis and a negative Cotton effect for the -configuration.

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 C 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.