Uniquely shaped double-decker buckyferrocenes--distinct electron donor-acceptor interactions

Area of Science:

• Materials Science
• Photochemistry
• Quantum Chemistry

Background:

• Double-decker buckyferrocenes are novel molecular architectures featuring intimate fullerene/ferrocene contacts.
• Understanding electron donor-acceptor interactions is key to their photophysical properties.

Purpose of the Study:

• To investigate ground- and excited-state interactions in C(2v) and D(5d) isomers of double-decker buckyferrocenes.
• To elucidate the mechanisms of excited-state deactivation and charge transfer.

Main Methods:

• Quantum chemical calculations.
• Steady-state absorption and fluorescence spectroscopy.
• Time-resolved fluorescence and femtosecond pump-probe experiments.

Main Results:

• Appreciable ground-state charge redistribution between ferrocene donors and fullerene acceptor observed.
• Intervalence charge-transfer transition identified in the C(2v) isomer.
• Fluorescence quenching in buckyferrocenes indicates rapid formation of radical ion-pair states (lifetimes 12-39 ps).

Conclusions:

• Double-decker buckyferrocenes display significant intramolecular interactions influencing their electronic properties.
• Radical ion-pair state formation is the dominant excited-state deactivation pathway.
• These findings provide crucial insights into charge transfer dynamics in complex molecular systems.