Use of circularly polarized luminescence following circularly polarized excitation as a probe of the chiral structure of octadentate complexes of Eu(III) and Tb(III) with cyclic polyazaphosphinic acid ligands

In this work we report on the use of circularly polarized luminescence following circularly polarized excitation (CPE/CPL) to examine a series of complexes of Eu(III) and Tb(III) with octadentate ligands based on the structure of the tetraazacyclododecane ring. Similarities in the CPL spectra from the series of complexes are interpreted in terms of similarity of structures. CPL from the Tb(III) complexes are quite large, larger than those observed from the corresponding Eu(III) species, and contrary to predictions based upon established selection rules for these f ↔ f transitions. The general utility of these types of measurements is also presented.