Synthesis, Optical Investigation and Biological Properties of Europium(III) Complexes with 2-(4-Chlorophenyl)-1-(2-Hydroxy-4-Methoxyphenyl)Ethan-1-one and Ancillary Ligands.

Synthesis and photoluminescence behaviour of six novel europium complexes with novel β-hydroxyketone ligand, 2-(4-chlorophenyl)-1-(2-hydroxy-4-methoxyphenyl)ethan-1-one (CHME) and 2,2'-bipyridine (bipy) or neocuproine (neo) or 1,10-phenanthroline (phen) or 5,6-dimethyl-1,10-phenanthroline (dmphen) or bathophenanthroline (bathophen) were reported in solid state. The free ligand CHME and europium complexes, Eu(CHME)3.2H2O [1] Eu(CHME)3.bipy [2], Eu(CHME)3.neo [3], Eu(CHME)3.phen [4], Eu(CHME)3.dmphen [5] and Eu(CHME)3.bathophen [6]were characterized by elemental analysis, FT-IR and 1H-NMR. The photoluminescence emission spectra exhibited four characteristic peaks arising from the 5D0 → 7FJ (J = 1-4) transitions of the europium ion in the solid state on monitoring excitation at λex = 395 nm. The luminescence decay curves of these europium complexes possess single exponential behaviour indicating the presence of a single luminescent species and having only one site symmetry in the complexes. The luminescence quantum efficiency (η) and the experimental intensity parameters, Ω 2 and Ω 4 of europium complexes have also been calculated on the basis of emission spectra and luminescence decay curves. In addition, the antimicrobial and antioxidant activities were also studied of the investigated complexes.