Green emissive Tb(III) complexes based on photosensitizing antenna: Synthesis and optoelectronic analysis

Abstract

Mononuclear octacoordinated ternary Tb(III) complexes involving 1,1,1-trifluoroacteylacetone (tfaa) as main ligand and monodentate or bidentate moieties as secondary ligand, were prepared. Tri-n-octyl phosphine oxide (TOPO) serves as a monodentate ligand with a single donor site (–O), while 1,10-phenanthroline and its derivatives function as bidentate ligands with –N as the donor atoms. The molecular stoichiometry and bonding environment about Tb(III) ion in synthesized samples were confirmed with the help of elemental analysis and the spectroscopic studies of FTIR and proton NMR, respectively. The octacoordinated arrangement around trivalent lanthanides was the outcome of their interactions occurs with oxygen donor sites in T1 and nitrogen sites in T2-T4. The optical investigation was concentrated on examining the absorption, excitation, emission and lifetime spectral data of the complexes. The dominating peak in Tb(III) complexes observed at around 545 nm is accountable for their green color. Thermogravimetric analysis demonstrates the stability of the complexes up to 150–250 °C. The synthesized complexes exhibit significant opto-electronic characteristics and large thermal stability, making them potentially suitable for lighting applications.