Trivalent lanthanide ions show interesting optical properties. Keeping this in view, five Sm(III) complexes were synthesized using 4-oxo-4H-1-benzopyran-3-carboxaldehyde (L) as primary ligand along with 1,10-Phenanthroline (Phen); Bipyridine (Bipy); Bathophenanthroline (Bathophen) and Neocuproine(Neo) as secondary ligands. Characterizations of prepared complexes were carried out by means of FTIR, elemental analysis, UV–vis, ESI-MS⁺, thermal studies, PXRD, FESEM, and luminescence studies. Thermal studies confirmed the good thermal stability of complexes. Sharp peaks in X-ray diffractograms suggest their crystalline nature. The photoluminescence process in complexes has been thoroughly studied and discussed in liquid and powder state. The complexes show ⁴G_5/2®⁶H_j transitions where j = 5/2, 7/2, and 9/2, analogous tocharacteristic emission peaks of Sm(III) ion at ~ 566, 601, and 648 nm, respectively. The complexes demonstrate intense emission peaks at ~ 601 in liquid and ~ 648 nm in a powder state, which is responsiblefor bright orange and red emission, respectively. The synergistic effect of secondary ligands was responsible for longer luminescence lifetime and enhanced emission intensity in ternary complexes. Attractive photoluminescenceproperties of complexes could play a vital role in electroluminescent devices, bio-assays, liquid lasers, OLEDs, etc.