Synthesis, characterization, enhanced photoluminescence, antimicrobial and antioxidant activities of novel Sm(III) complexes containing 1-(2-hydroxy-4,6-dimethoxyphenyl)ethanone and nitrogen containing ancillary ligands

Abstract

Two novel ternary Sm(III) complexes, Sm(HDMPE)3Phen (C1) and Sm(HDMPE)3Bath (C2) were successfully synthesized by adopting solution-precipitation method. The synthesized complexes were investigated by various techniques including elemental analysis, FT-IR, 1H-NMR and photoluminescence spectroscopy techniques. The luminescence decay time and energy transfer mechanism of the complexes were also investigated. Both these complexes exhibit pure sharp emission bands from the intra f–f transitions of samarium ion, 4G5/2 → 6H5/2 (564 nm), 4G5/2 → 6H7/2 (600 nm) and 4G5/2 → 6H9/2 (646 nm) on monitoring the excitation at 373 nm, in the solid state at room temperature. The Sm(III) ion could be sensitized efficiently by β-hydroxyketone ligand, 1-(2-hydroxy-4,6-dimethoxyphenyl)ethanone (HDMPE) and the introduction of ancillary ligand 1,10-phenanthroline (Phen) or bathophenanthroline (Bath) resulted in enhanced photoluminescence. The complex, Sm(HDMPE)3Bath showed higher emission intensity and longer life time (τ) than Sm(HDMPE)3Phen complex. The photoluminescence emission spectra show that these ternary complexes might be promising candidate in advanced displays and lighting systems. Moreover, the antimicrobial and antioxidant activities of these complexes were studied. The results reveal that complex C2 exhibited excellent antimicrobial and antioxidant activities.