TY  - JOUR
A1  - Herbst, Stefanie
A1  - Soberats, Bartolome
A1  - Leowanawat, Pawaret
A1  - Stolte, Matthias
A1  - Lehmann, Matthias
A1  - Würthner, Frank
T1  - Self-assembly of multi-stranded perylene dye J-aggregates in columnar liquid-crystalline phases
JF  - Nature Communications
N2  - Many discoid dyes self-assemble into columnar liquid-crystalline (LC) phases with packing arrangements that are undesired for photonic applications due to H-type exciton coupling. Here, we report a series of crystalline and LC perylene bisimides (PBIs) self-assembling into single or multi-stranded (two, three, and four strands) aggregates with predominant J-type exciton coupling. These differences in the supramolecular packing and optical properties are achieved by molecular design variations of tetra-bay phenoxy-dendronized PBIs with two N–H groups at the imide positions. The self-assembly is driven by hydrogen bonding, slipped π–π stacking, nanosegregation, and steric requirements of the peripheral building blocks. We could determine the impact of the packing motifs on the spectroscopic properties and demonstrate different J- and H-type coupling contributions between the chromophores. Our findings on structure–property relationships and strong J-couplings in bulk LC materials open a new avenue in the molecular engineering of PBI J-aggregates with prospective applications in photonics.
KW  - liquid crystals
KW  - self-assembly
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319914
VL  - 9
ER  - 
TY  - JOUR
A1  - Hecht, Markus
A1  - Leowanawat, Pawaret
A1  - Gerlach, Tabea
A1  - Stepanenko, Vladimir
A1  - Stolte, Matthias
A1  - Lehmann, Matthias
A1  - Würthner, Frank
T1  - Self‐Sorting Supramolecular Polymerization: Helical and Lamellar Aggregates of Tetra‐Bay‐Acyloxy Perylene Bisimide
JF  - Angewandte Chemie International Edition
N2  - A new perylene bisimide (PBI), with a fluorescence quantum yield up to unity, self‐assembles into two polymorphic supramolecular polymers. This PBI bears four solubilizing acyloxy substituents at the bay positions and is unsubstituted at the imide position, thereby allowing hydrogen‐bond‐directed self‐assembly in nonpolar solvents. The formation of the polymorphs is controlled by the cooling rate of hot monomer solutions. They show distinctive absorption profiles and morphologies and can be isolated in different polymorphic liquid‐crystalline states. The interchromophoric arrangement causing the spectral features was elucidated, revealing the formation of columnar and lamellar phases, which are formed by either homo‐ or heterochiral self‐assembly, respectively, of the atropoenantiomeric PBIs. Kinetic studies reveal a narcissistic self‐sorting process upon fast cooling, and that the transformation into the heterochiral (racemic) sheetlike self‐assemblies proceeds by dissociation via the monomeric state.
KW  - liquid crystals
KW  - noncovalent interactions
KW  - self-assembly
KW  - structure elucidation
KW  - supramolecular chemistry
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224586
VL  - 59
IS  - 39
SP  - 17084
EP  - 17090
ER  -