TY  - JOUR
A1  - Garain, Swadhin
A1  - Shoyama, Kazutaka
A1  - Ginder, Lea-Marleen
A1  - Sárosi, Menyhárt
A1  - Würthner, Frank
T1  - The delayed box: biphenyl bisimide cyclophane, a supramolecular nano-environment for the efficient generation of delayed fluorescence
T2  - Journal of the American Chemical Society
N2  - Activating delayed fluorescence emission in a dilute solution via a non-covalent approach is a formidable challenge. In this report, we propose a strategy for efficient delayed fluorescence generation in dilute solution using a non-covalent approach via supramolecularly engineered cyclophane-based nanoenvironments that provide sufficient binding strength to π-conjugated guests and that can stabilize triplet excitons by reducing vibrational dissipation and lowering the singlet–triplet energy gap for efficient delayed fluorescence emission. Toward this goal, a novel biphenyl bisimide-derived cyclophane is introduced as an electron-deficient and efficient triplet-generating host. Upon encapsulation of various carbazole-derived guests inside the nanocavity of this cyclophane, emissive charge transfer (CT) states close to the triplet energy level of the biphenyl bisimide are generated. The experimental results of host–guest studies manifest high association constants up to 10\(^4\) M\(^{–1}\) as the prerequisite for inclusion complex formation, the generation of emissive CT states, and triplet-state stabilization in a diluted solution state. By means of different carbazole guest molecules, we could realize tunable delayed fluorescence emission in this carbazole-encapsulated biphenyl bisimide cyclophane in methylcyclohexane/carbon tetrachloride solutions with a quantum yield (QY) of up to 15.6%. Crystal structure analyses and solid-state photophysical studies validate the conclusions from our solution studies and provide insights into the delayed fluorescence emission mechanism.
KW  - aromatic compounds
KW  - complexation
KW  - encapsulation
KW  - fluorescence
KW  - hydrocarbons
Y1  - 2024
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/37038
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-370385
SN  - 0002-7863
VL  - 146
IS  - 31
ER  -