ELECTRONIC-SPECTRA, OPTICAL-ACTIVITY, AND CRYSTAL-FIELD ENERGY-LEVEL STRUCTURE OF DY3+ IN TRIGONAL NA-3[DY(ODA)(3)]CENTER-DOT-2NACLO(4)CENTER-DOT-6H(2)O CRYSTALS

Optical absorption and emission measurements are used to locate and assign 152 crystal-field energy levels split out of the 4f(9) electronic configuration of Dy3+ in Na-3[Dy(oda)(3)]. 2NaClO(4) . 6H(2)O (where oda denotes an oxydiacetate ligand). The absorption measurements span the 230-1800 nm wavelength range, and they encompass all optical transitions that may occur between the H-6(15/2) ground multiplet and 63 different excited multiplet manifolds of the 4f(9)(Dy3+) electronic configuration. The emission measurements span the 470-900 nm wavelength range, and they encompass all transitions that originate within the F-4(3)(9/2) excited multiplet manifold (centered at ca. 21 100 cm(-1) above ground) and terminate on levels split out of the H-6(J) (J = 15/2, 13/2, 11/2, 9/2, and 7/2) and F-6(J) (J = 11/2, 9/2) multiplet manifolds of 4f(9)(Dy3+). The combined absorption and emission measurements provide access to the energy-level structures of 65 4f(9)[SL]J multiplet manifolds of Dy3+ (all multiplet manifolds with baricenter energies <43 000 cm(-1) above ground). The site symmetry of Dy3+ ions in Na-3[Dy(oda)(3)]. 2NaClO(4) . 6H(2)O is D-3, and all crystal-field levels split out of the 4f(9)(Dy3+) electronic configuration are Kramers doublets with either E' or E '' symmetry in the D-3 double-rotation group. Among the 348 crystal-field levels predicted for the 65 multiplet manifolds examined in this study, 152 are both located and assigned (with respect to crystal-field symmetry type, E' or E '', and principal [SL]J multiplet: parentage). Symmetry assignments are based on results obtained from both linearly and circularly polarized absorption and emission measurements. The 152 assigned levels are analyzed in terms or a model Hamiltonian that includes consideration of both isotropic and non-isotropic 4f-electron/crystal-field interactions, and the interaction parameters derived from this analysis are discussed and then compared with those obtained for other Na-3[Ln(oda)(3)]. 2NaClO(4) . 6H(2)O systems and for Dy3+ in other crystalline hosts. The parametrized form of the model Hamiltonian derived from the energy-level analysis yields calculated-to-experimental data fits with an rms deviation of 8.2 cm(-1) (between calculated and observed energies). Several multiplet-to-multiplet transition regions of Dy3+ in Na-3[Dy(oda)(3)]. 2NaClO(4) . 6H(2)O exhibit strong chiroptical activity, and the circular dichroism and circularly polarized luminescence spectra observed in these regions are presented and discussed. Quantitatively determined line strengths are reported for 39 of the transitions observed in the unpolarized axial absorption spectra.