%0 Journal Article %1 Hong_2022 %A Hong, Yongseok %A Schlosser, Felix %A Kim, Woojae %A Würthner, Frank %A Kim, Dongho %D 2022 %I American Chemical Society (ACS) %J J. Am. Chem. Soc. %K myown %N 34 %P 15539--15548 %R 10.1021/jacs.2c03916 %T Ultrafast Symmetry-Breaking Charge Separation in a Perylene Bisimide Dimer Enabled by Vibronic Coupling and Breakdown of Adiabaticity %U https://doi.org/10.1021%2Fjacs.2c03916 %V 144 %X Perylene bisimides (PBIs) have received great attention in their applicability to optoelectronics. Especially, symmetry-breaking charge separation (SB-CS) in PBIs has been investigated to mimic the efficient light capturing and charge generation in natural light-harvesting systems. However, unlike ultrafast CS dynamics in donor–acceptor heterojunction materials, ultrafast SB-CS in a stacked homodimer has still been challenging due to excimer formation in the absence of rigidifying surroundings such as a special pair in the natural systems. Herein, we present the detailed mechanism of ultrafast photoinduced SB-CS occurring in a 1,7-bis(N-pyrrolidinyl) PBI dimer within a cyclophane. Through narrow-band and broad-band transient absorption spectroscopy, we demonstrate that ultrafast SB-CS in the dimer is enabled by the combination of (1) vibrationally coherent charge-transfer resonance-enhanced excimer formation and (2) breakdown of adiabaticity (formation of SB-CS diabats) in the excimer state via structural and solvent fluctuation. Quantum chemical calculations also underpin that the participation of strong electron-donating substituents in overall vibrational modes plays a crucial role in triggering the ultrafast SB-CS. Therefore, our work provides an alternative route to facilitate ultrafast SB-CS in PBIs and thereby establishes a novel strategy for the design of optoelectronic materials.

@article{Hong_2022, abstract = {Perylene bisimides (PBIs) have received great attention in their applicability to optoelectronics. Especially, symmetry-breaking charge separation (SB-CS) in PBIs has been investigated to mimic the efficient light capturing and charge generation in natural light-harvesting systems. However, unlike ultrafast CS dynamics in donor–acceptor heterojunction materials, ultrafast SB-CS in a stacked homodimer has still been challenging due to excimer formation in the absence of rigidifying surroundings such as a special pair in the natural systems. Herein, we present the detailed mechanism of ultrafast photoinduced SB-CS occurring in a 1,7-bis(N-pyrrolidinyl) PBI dimer within a cyclophane. Through narrow-band and broad-band transient absorption spectroscopy, we demonstrate that ultrafast SB-CS in the dimer is enabled by the combination of (1) vibrationally coherent charge-transfer resonance-enhanced excimer formation and (2) breakdown of adiabaticity (formation of SB-CS diabats) in the excimer state via structural and solvent fluctuation. Quantum chemical calculations also underpin that the participation of strong electron-donating substituents in overall vibrational modes plays a crucial role in triggering the ultrafast SB-CS. Therefore, our work provides an alternative route to facilitate ultrafast SB-CS in PBIs and thereby establishes a novel strategy for the design of optoelectronic materials.}, added-at = {2022-10-04T10:59:42.000+0200}, author = {Hong, Yongseok and Schlosser, Felix and Kim, Woojae and Würthner, Frank and Kim, Dongho}, biburl = {https://www.bibsonomy.org/bibtex/2543ed399471cb62677dc49fd2a7de038/wuerthner_group}, doi = {10.1021/jacs.2c03916}, interhash = {c94b732b548da1cef532bb2afec3a5df}, intrahash = {543ed399471cb62677dc49fd2a7de038}, journal = {J. Am. Chem. Soc.}, keywords = {myown}, month = aug, number = 34, pages = {15539--15548}, publisher = {American Chemical Society ({ACS})}, timestamp = {2022-10-04T10:59:42.000+0200}, title = {Ultrafast Symmetry-Breaking Charge Separation in a Perylene Bisimide Dimer Enabled by Vibronic Coupling and Breakdown of Adiabaticity}, url = {https://doi.org/10.1021%2Fjacs.2c03916}, volume = 144, year = 2022 }