TY  - JOUR
A1  - Mahl, Magnus
A1  - Shoyama, Kazutaka
A1  - Krause, Ana‐Maria
A1  - Schmidt, David
A1  - Würthner, Frank
T1  - Base‐Assisted Imidization: A Synthetic Method for the Introduction of Bulky Imide Substituents to Control Packing and Optical Properties of Naphthalene and Perylene Imides
JF  - Angewandte Chemie International Edition
N2  - We report the direct imidization of naphthalene and perylene dicarboxylic anhydrides/esters with bulky ortho,ortho‐diaryl‐ and ortho,ortho‐dialkynylaniline derivatives. This imidization method uses n‐butyllithium as a strong base to increase the reactivity of bulky amine derivatives, proceeds under mild reaction conditions, requires only stoichiometric amounts of reactants and gives straightforward access to new sterically crowded rylene dicarboximides. Mechanistic investigations suggest an isoimide as intermediary product, which was converted to the corresponding imide upon addition of an aqueous base. Single‐crystal X‐ray diffraction analyses reveal dimeric packing motifs for monoimides, while two‐side shielded bisimides crystallize in isolated molecules without close π–π‐interactions. Spectroscopic investigations disclose the influence of the bulky substituents on the optical properties in the solid state.
KW  - dyes
KW  - fluorescence
KW  - imidization
KW  - perylene imide
KW  - solid-state emitters
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218246
VL  - 59
IS  - 32
SP  - 13401
EP  - 13405
ER  - 
TY  - JOUR
A1  - Seifert, Sabine
A1  - Shoyama, Kazutaka
A1  - Schmidt, David
A1  - Würthner, Frank
T1  - An electron-poor C\(_{64}\) nanographene by palladium-catalyzed cascade C-C bond formation: one-pot synthesis and single-crystal structure analysis
JF  - Angewandte Chemie-International Edition
N2  - Herein, we report the one-pot synthesis of an electron-poor nanographene containing dicarboximide groups at the corners. We efficiently combined palladium-catalyzed Suzuki-Miyaura cross-coupling and dehydrohalogenation to synthesize an extended two-dimensional pi-scaffold of defined size in a single chemical operation starting from N-(2,6-diisopropylphenyl)-4,5-dibromo-1,8-naphthalimide and a tetrasubstituted pyrene boronic acid ester as readily accessible starting materials. The reaction of these precursors under the conditions commonly used for Suzuki-Miyaura cross-coupling afforded a C\(_{64}\) nanographene through the formation of ten C-C bonds in a one-pot process. Single-crystal X-ray analysis unequivocally confirmed the structure of this unique extended aromatic molecule with a planar geometry. The optical and electrochemical properties of this largest ever synthesized planar electron-poor nanographene skeleton were also analyzed.
KW  - Graphene nanoribbons
KW  - Liquid-crystalline
KW  - dyes/pigments
KW  - polycyclic aromatic hydrocarbons
KW  - two-dimensional nanostructures
KW  - Aromatic-hydrocarbon
KW  - Carbon
KW  - Dyes
KW  - Functionalization
KW  - cascade reactions
KW  - nanographene
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188889
VL  - 55
IS  - 22
ER  -