- Previous Article
- Next Article
- Table of Contents
Journal of Physical Chemistry B, Vol.106, No.6, 1508-1514, 2002
The effect of excited state energy transfer on the circularly polarized luminescence from sol-gels containing racemic complexes of Eu(III): Theory and experiment
Excited state energy transfer between enantiomers in concentrated samples will diminish the differential excited state concentrations of a photoenriched racemic mixture, and this phenomenon will be reflected in a decrease in the observed circularly polarized luminescence as compared to low concentration samples where this energy transfer process can be neglected. Such a decrease is reported here fur complexes of Eu(III) with 2,6-pyridine-dicarboxylate and 2,2'-bipyridine-N,N'-dioxide = bpyO(2) ligands. This work represents the first experimental observation of this phenomenon far samples prepared in high concentration by incorporation into high-quality strain-free sol-gels. These results are fit to a theoretical model appropriate for randomly oriented and dispersed solute chromophores, and the Forster critical transfer distance is obtained. Limitations of the model and other experimental difficulties are described.