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, Ω2 and Ω4 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.