LAUSR

The synthesis of luminescent complexes of Sm(III) with the general formula [Sm(L)3·(X)] was done in powder form. In the formula, L is 6-methyl-4-oxo-4H-1-benzopyran-3-carboxaldehyde and X represents 2H2O (C1), 1,10-phenanthroline (C2), 2,2′-bipyridine (C3); bathophenanthroline (C4) and neocuproine (C5). The complexes were characterized by using various analytical and spectroscopic tools like elemental analysis, electrospray ionization mass spectrometry (ESI–MS+), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy, thermo-gravimetric analysis/ differential thermal gravimetric analysis (TGA/DTG), field emission scanning electron microscopy (FESEM), powder X-ray diffraction (XRD), and photoluminescence (PL) studies. TGA/DTG showed high thermal stability of synthesized complexes. Powder XRD depicts that the average particle size lies in the nano-range. On monitoring at the excitation wavelength of 370 nm, the complexes display characteristic luminescence peaks of Sm(III) at ~ 564, ~ 600 and ~ 647 nm assigned to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, and 4G5/2 → 6H9/2 transitions, respectively, with the most intense transition at ~ 600 (orange emission) and ~ 647 nm (bright red emission) in liquid and powder state, respectively. The investigations demonstrate that the synthesized novel complexes might be practically useful in electroluminescent devices, bio-assays, and liquid lasers due to their attractive photoluminescent properties.