Spectral and energetic transformation of femtosecond light impulses in the Eu3+ complex with dehydroacetic acid

A solid state Eu3+ complex with dehydroacetic acid (DHA) has been synthesized and characterized by elemental analysis, UV-visible, FT-IR, FT-Raman, powder and single-crystal X-ray diffraction and optical spectroscopy studies. The complex has formula [Eu(DHA)2(H2O)5]NO3 with DHA = C8H7O4−, where the europium ions is in monocapped distorted square antiprism environment with coordination number nine. Its photophysical properties have been analyzed in terms of its molecular structure and DFT calculations performed for the representative crystal fragment including Eu3+ and two DHA ligands. The luminescence and dynamics of the excited states depopulation have been studied using femtosecond laser excitation. The energy transfer mechanism between the ligand and Eu3+ electronic energy levels has been proposed. The obtained results have been compared to those of Gd3+ dehydroacetic derivative.