Luminescence and crystal field parameters of the Na3[Eu(DPA)3]•12H2O complex in a single crystalline state

Single crystals of Na-3[Eu(DPA)(3)]. 12H(2)O (DPA=dipicolinato) were grown by the temperature lowering method. Luminescence and excitation spectra of the crystals are reported. Detailed line assignments for the D-5(0)-->F-7(j) (J=0, 1, 2, 3 and 4) transitions are carried out with the simulation of the luminescence lines in the frame of the free-ion and the crystal-field Hamiltonians. Although the systematic analysis on the baricenter shifting of each excited J states due to the complexation is need for the emission process, the set of the refined crystal field parameters under the D-2 site symmetry satisfactorily reproduces the fine splitting of the emission lines. It proves the fact that the characteristic line splittings are strongly correlated with the site symmetry of Eu(III). (C) 1998 Elsevier Science S.A.