Rapid energy transfer process through π-conjugation network in meta -linked branching dendrimers

• Published in: Physica status solidi. C Vol. 8; no. 1; pp. 155 - 158
• Main Authors: Akai, Ichiro, Miyanari, Kuniaki, Shimamoto, Tomoshige, Fujii, Atsuhiro, Kimura, Mutsumi
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.01.2011; WILEY‐VCH Verlag
• Subjects: dendrimer; energy transfer; light-harvesting; temperature dependence; torsional vibration
• ISSN: 1862-6351; 1610-1642
• DOI: 10.1002/pssc.201000638

We investigated rapid energy transfer (ET) processes in dendrimers having meta ‐linked branching light harvesting antennas. It was found that, at room temperature (RT), the rapid ET occurs efficiently from the antennas to the core and gives rise to intense core‐PL bands under the selective excitation on the antenna. However, the ET efficiency impairs at lower temperatures than ∼100 K. For understanding these experimental results, we analyzed molecular vibrations and molecular orbitals (MOs) of a simple model molecule. From these analyses, it was demonstrated that, at RT, the torsional vibration of the entire antenna subunit is excited sufficiently and the torsional vibration improves the co‐planarity between the core and the antenna subunit, consequently, the rapid ET is realized by the short‐range interaction between the π*‐MOs of the core and the antenna. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)