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  - Bold, Kevin
A1  - Stolte, Matthias
A1  - Shoyama, Kazutaka
A1  - Krause, Ana‐Maria
A1  - Schmiedel, Alexander
A1  - Holzapfel, Marco
A1  - Lambert, Christoph
A1  - Würthner, Frank
T1  - Macrocyclic Donor‐Acceptor Dyads Composed of Oligothiophene Half‐Cycles and Perylene Bisimides
JF  - Chemistry – A European Journal
N2  - A series of donor‐acceptor (D−A) macrocyclic dyads consisting of an electron‐poor perylene bisimide (PBI) π‐scaffold bridged with electron‐rich α‐oligothiophenes bearing four, five, six and seven thiophene units between the two phenyl‐imide substituents has been synthesized and characterized by steady‐state UV/Vis absorption and fluorescence spectroscopy, cyclic and differential pulse voltammetry as well as transient absorption spectroscopy. Tying the oligothiophene strands in a conformationally fixed macrocyclic arrangement leads to a more rigid π‐scaffold with vibronic fine structure in the respective absorption spectra. Electrochemical analysis disclosed charged state properties in solution which are strongly dependent on the degree of rigidification within the individual macrocycle. Investigation of the excited state dynamics revealed an oligothiophene bridge size‐dependent fast charge transfer process for the macrocyclic dyads upon PBI subunit excitation.
KW  - donor-acceptor dyad
KW  - macrocycle
KW  - oligothiophene
KW  - perylene bisimide
KW  - photoinduced electron transfer
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-276435
VL  - 28
IS  - 30
ER  -