Eu3+, Yb3+ and Eu3+-Yb3+ Complexes with Salicylic Acid and 1,10-Phenanthroline: Synthesis, Photoluminescent Properties and Energy Transfer

Abstract

This paper reports the synthesis of mononuclear Eu(3+), Yb(3+) and binuclear Eu(3+)-Yb(3+) complexes by solution technique, maintaining the stoichiometric ratios of salicylic acid (sal) and 1,10-phenanthroline (phen) as ligands and their structural, optical and morphological properties were demonstrated. The FTIR absorption spectra indicates that sal and phen are coordinated to the rare earth ion through the chemical bonds formed between oxygen and nitrogen atoms of the ligands and rare earth ion. The UV-vis absorption spectra of the complexes reflect the absorption spectra of the ligands and there is no significant change in the wavelength and band profiles between the spectra of the ligands and that of complexes except a slight red shift. The photoluminescent emission spectra of the complexes in visible and near-infrared (NIR) region was recorded and indicated the emission quenching in complex (2) due to the energy transfer from Eu(3+) ion to Yb(3+) ion. The morphological properties of the complexes as characterized by SEM revealed different morphologies of mononuclear and binuclear complexes.

Macrocyclic anthracene-anchored calix[4]arene as a sensitive and selective fluorescent chemosensor for ytterbium ions

“…This band disappears and shifts downward to 1648 cm ¡1 in the C4PA-Yb 3C complex structure which suggests that the coordinate bonds form between oxygen atom of carbonyl group and Yb 3C . In addition, the free isolated C D N group at around 1590 cm ¡1 as reported in literature [24] also shifts to lower wavenumber at 1560. These shifts and decreases in the IR signals of C4PA prove that a coordination between N atoms of imine group and Yb 3C is taken place.…”

Azopolymer triggered electrophoretic deposition of MnO2-carbon nanotube composites and polypyrrole coated carbon nanotubes for supercapacitors

“…4 Moreover, it is an important anti-oxidant. The interactions of salicylate molecules with organic and inorganic materials [5][6][7][8][9] have generated signicant interest in applications of such molecules as building blocks of metal-organic frameworks 10 and surface modication agents in colloid chemistry. 3 Many functional properties of salicylates are related to their chemical structure, containing COOH and OH groups, bonded to the adjacent carbon atoms of the aromatic ring.…”

Energy transfer and photoluminescence properties of lanthanide-containing polyoxotitanate cages coordinated by salicylate ligands

“…16 The salicylate-Ti 4+ moiety is found to be an effective visible light responsive 'antenna' for Ln 3+ sensitisation, although salicylate itself is usually considered inefficient in this role. [32][33][34] Both visible (for Pr-1, Sm-1, Eu-1, Ho-1 and Er-1) and NIR (for Nd-1 and Er-1) photoluminescence can be sensitised by visible light excitation up to 475 nm, representing a special example in which one visible-responsive ligand system is suitable for Ln 3+ ion sensitisation across the visible-NIR spectrum. [35][36][37][38][39] The charge-transfer process from salicylate HOMO to Ti 4+ d orbitals is proposed to account for the largely red-shifted excitation wavelengths, supported by both steady-state and timeresolved photoluminescence spectral data.…”

“…43 Therefore, this band can be attributed to the excitation of the salicylate ligand, undergoing a S 0 → S 1 transition at this excitation wavelength. [32][33][34] Apart from the Ln 3+ -centred emission, excitation at 300 nm also leads to a broad emission band at ca. 450 nm for Nd-1, Sm-1, Ho-1 and Er-1, corresponding to the fluorescence of salicylate S 1 state.…”