Ultrafast Intrinsic Electron Transfer Dynamics in a Sterically Preorganized Corrole-Perylene Bisimide Dyad

Area of Science:

• Organic Chemistry
• Photochemistry
• Materials Science

Background:

• Donor-acceptor (D-A) dyads are crucial for charge separation.
• Achieving efficient charge separation often requires specific molecular architectures and solvent environments.
• Understanding the mechanisms driving photoinduced electron transfer (PET) is key for designing new materials.

Purpose of the Study:

• To synthesize and characterize rigid D-A dyads comprising corrole (COR) and perylene bisimide (PBI) units.
• To investigate the electronic communication and photoinduced electron transfer (PET) mechanisms within these dyads.
• To explore the role of molecular preorganization and solvent effects on charge separation dynamics.

Main Methods:

• Aza-annulation strategy using a modified Pictet-Spengler reaction for synthesis.
• Spectroscopic studies including fluorescence quenching and femtosecond transient absorption.
• Investigation of solvent-dependent charge separation dynamics in various media.

Main Results:

• Successfully synthesized rigid, directly linked COR-PBI dyads with N-methylation.
• Observed ultrafast, solvent-dependent photoinduced electron transfer from COR to PBI.
• Demonstrated persistent charge separation in viscous media, indicating intrinsic D-A driving force.

Conclusions:

• Rigid COR-PBI dyads facilitate efficient through-space electronic communication.
• Photoinduced electron transfer is primarily driven by preorganized D-A arrangement, not conformational gating.
• These dyads represent promising platforms for ultrafast charge separation applications.