Synthesis, properties, luminescence of mixed ligands complexes of acetylsalicylate and 1,10-phenantroline with some light rare earth elements

Abstract

Mixed ligands complexes of acetylsalicylic and 1,10-phenantroline of Ln(III) with the general formula Ln(AcSa)3(Phen).3H2O (Ln: Nd, Sm, Eu; AcSa-: Acetylsalicylate, Phen: 1,10-phenantroline) have been prepared. The characterization of these complexes have been studied by IR, thermal analysis and mass-spectroscopy methods; The luminescence of complexes was investigated by measuring the excitation and emission spectra. IR spectra suggest that complexes have been synthesised successfully. Mass-spectroscopy showed that the complexes are monomes and they are stable. The intramolecular ligand-to-rare earth energy transfer mechanisms were discussed. The emission spectra of Eu(AcSa)3(Phen).3H2O consist of the 5D0 → 7F2 and 5D0 → 7F1 dominant transitions located at 614 nm and 593 nm, the weaker 5D0 → 7F4 transition located at 699 nm, the weakest 5D0 → 7F3 transition located at 654 nm. The emission spectra of the Sm(AcSa)3(Phen).3H2O displayed three bands, in there, the 4G5/2 – 6H7/2 and 4G5/2 – 6H9/2 equivalent transitions located at 599 nm and 645 nm, the weakest 4G5/2 – 6H5/2 transition located at 564 nm. The emission spectra of the Nd(AcSa)3Phen.3H2O displayed one band at 440 nm, i.e. 4F3/2 – 4I9/2 energy level of Nd3+ was observed. These complexes showed room-temperature photoluminescence