LINEARLY POLARIZED LUMINESCENCE SPECTRA OF EU(2,6-PYRIDINE-DICARBOXYLATE)(3)(3-) IN HYDROXYLIC SOLUTION

Emission spectra and linearly polarized emission spectra are reported for Eu(2,6-pyridine-dicarboxylate = DPA)3(3-) in a hydroxylic glass (w ater/ethylene glycol, 1:2 by volume) at 157 K. The splitting pattern o f the F-7J <-- 5D0 (J = 1, 2, 4) emission bands (in order of decreasin g energy A2, E; E, E and E, A2, E, E) and their polarization anisotrop ies upon 465.8 nm irradiation are consistent with the complex having a pproximate D3 symmetry. The two F-7(1) <-- 5D0 bands have predominantl y ( greater than or similar to 80%) magnetic dipole character. The pol arization data upon excitation in the 290 nm absorption show that this band involves pi --> pi ligand transitions, polarized perpendicular to the C2 axis of the DPA ligand. The angle between the C3 axis of the complex and the normal vector to the plane of the pyridine ring is fo und to be 41-degrees +/- 5-degrees.