Samarium(III) complexes as potential orange-red light emitters: A comprehensive study on the influence of coordination environment

• Octacoordinated Sm(III) complexes with β-diketonate (BBA) and various bidentate ligands were successfully synthesized and comprehensively characterized. • Neutral ligands significantly modulated photoluminescence intensity and emission color across various ligands. • Ligand-dependent energy transfer from the organic antenna to Sm 3+ ion was observed, with enhanced emission in S2 and S4. • Colorimetric analysis revealed high color purity, warm emission and excellent CRI values suitable for lighting and display applications. Four octacoordinated [Sm(BBA) 3 L] complexes incorporating different neutral moieties (L) were successfully synthesized and thoroughly characterized using elemental analysis, FT-IR spectroscopy, thermogravimetric analysis (TGA) and proton NMR spectroscopy. The influence of ancillary ligands on the photoluminescent behavior of Sm(III) ion was examined to evaluate their role in emission enhancement. Photoluminescence studies revealed that varying the neutral ligands enables tunable emission colors from reddish-orange to pinkish-red and significantly modulates emission intensity. Energy transfer mechanism is discussed in detail, along with luminescence lifetimes and optical and electronic band gap evaluations. The thermal stability of the complexes was confirmed through TGA. Collectively, the findings from these analyses highlight the potential of these complexes for applications in sensing and light emissive devices.