Ta. Hopkins et al., OPTICAL-SPECTRA AND ELECTRONIC-STATE STRUCTURE OF -XDYX(DPA)(3)]CENTER-DOT-NACLO4-CENTER-DOT-10H(2)O CRYSTALS( IN HEXAGONAL NA), Inorganic chemistry, 34(19), 1995, pp. 4879-4887
Polarized optical absorption and emission measurements are used to loc
ate and assign 91 crystal-field energy levels split out of the 4f(9) e
lectronic configuration of Dy3+ in hexagonal Na-3[Yb1-xDyx(dpa)(3)]. N
aClO4 . 10H(2)O (x = 0.05, 0.2, 1; dpa = dipicolinate dianion = 2,6-py
ridinedicarboxylate). The absorption measurements span the 300-1800 nm
wavelength range, and the emission measurements span the 470-775 nm w
avelength range. The combined absorption and emission measurements pro
vide access to the energy-level structures of 35 4f(9) [SL]J multiplet
manifolds of Dy3+, which include all multiplet manifolds with baricen
ter energies < 33 000 cm(-1) above ground. The site symmetry of the Dy
3+ ions in hexagonal Na-3[Yb1-xDyx(dpa)(3)]. NaClO4 . 10H(2)O is D-3,
and all crystal-field levels split out of the 4f(9)(Dy3+) electronic c
onfiguration are Kramers doublets with either E' or E '' symmetry in t
he D-3 double-rotation group. Among the 187 crystal-field levels predi
cted for the 35 multiplet manifolds examined in this study, 91 are bot
h located and assigned (with respect to crystal-field symmetry type, E
' or E '', and principal [SL]J multiplet parentage). The 91 assigned l
evels are analyzed in terms of a model Hamiltonian that includes consi
deration of both isotropic and non-isotropic 4f-electron/crystal-field
interactions. A parametrized form of this Hamiltonian is used to perf
orm parametric fits of calculated-to-experimental energy-level data, a
nd the results obtained from these fits show an rms deviation of 6.3 c
m(-1) between calculated and observed energies, The interaction parame
ters evaluated from these energy-level data fits are compared to those
for Dy3+ in other systems, with particular attention given to Dy(oda)
(3)(3-) in Na-3[Dy(oda)(3)]. 2NaClO(4) . 6H(2)O (where oda = oxydiacet
ate). The crystal-field energy-level structures of Dy(oda)(3)(3-) and
Dy(dpa)(3)(3-) show significant differences, and these differences are
discussed in terms of the ligand moieties that are present in the res
pective complexes. Among the more than 150 spectral features observed
and assigned in the unpolarized axial absorption spectra of Na-3[Dy(dp
a)(3)]. NaClO4 . 10H(2)O, 46 are sufficiently well-resolved to permit
quantitative determinations of transition line strengths, and these li
ne strengths are reported and discussed.