Department of Chemistry
Date of this Version
5-16-2000
Abstract
The ultrafast intrinsic dynamics of an organic dendrimer in solution and in a thin film is reported using fluorescence upconversion spectroscopy. Femtosecond decay is detected at higher emission energies, while at lower energies a fluorescence rise time (∼3 ps) was observed that is dependent on the solvent’s polarity. A strong excitation energy dependence of the decay pattern was also observed. Different synthetic functional groups that comprise the macromolecular dendrimer structure were investigated. The mechanism, which describes the complex dynamics in the dendrimer system, was found to be associated with the excitation of the attached chromophore nitroaminostilbene. These results indicate the absence of excited-state interactions of functional groups within the dendrimer macromolecule. A model, which includes the existence of an intermediate nonradiative state, is proposed to describe the complex ultrafast fluorescence dynamics in the dendrimer system.
Comments
Published in Phys. Rev. B 61:19 (May 2000), pp. 12732 - 12738. Copyright © 2000 The American Physical Society. Used by permission. URL: http://link.aps.org/abstract/PRB/v61/p12732 DOI: 10.1103/PhysRevB.61.12732