Energy migration in novel branched and cyclic aggregates

PHYS 332

Kevin V. Hagedorn, khagedor@umich.edu, Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109 and T. Goodson III, tgoodson@umich.edu, Department of Chemistry, University of Michigan-Ann Arbor, 930 North University Avenue, Ann Arbor, MI 48109.
The optical properties of a branched triarylamine system and a cyclic thiophene are reported. A dendrimer system which is energetically uniform shows a strong fluorescence rise in the absence of an energy gradient. The energy trapping mechanism is attributed to an exciton-phonon coupling process. This mechanism is preferable to a simple gradient because it allows for faster and more efficient exciton transfer, especially over long distances. We will also discuss a thiophene ring system with nanometer sized cavities. Measurements of the ultra fast transient absorption and fluorescence were preformed in order to understand the interaction between chromophores. The results show delocalized states in the macrocycle and also a strongly enhanced two photon cross section.
 

PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008