Luminescent 8-hydroxyquinoline derived tin(IV) complexes.

• 8-Hydroxyquinoline-based tin(IV) complexes have been synthesized and characterized. • Photophysical studies have been carried out in solvents of varying polarity. • All complexes show high fluorescence quantum yield apart from displaying longer lifetimes. • DFT calculations support the observed electronic and structural properties. Four different 8-hydroxyquinoline derivative-based tin(IV) complexes [(n Bu) 2 Sn(Cl-Q-CHO) 2 ] (1), [{(n Bu) 4 Sn 2 (Q-COO) 2 } 2 ] (2), [Ph 2 Sn(Cl)(Q-CHO)] (3) and [Ph 2 Sn(Cl)(Q-CH{OMe} 2)] (4) (Cl-Q-CHO = 5‑chloro-8-hydroxyquinolin-7-carbaldehyde; Q-COO− = 8-hydroxyquinolin-2-carboxylate; Q-CHO = 8-hydroxyquinolin-2-carbaldehyde and Q-CH{OMe} 2 = 2-(dimethoxy methyl)quinolin-8-ol) have been synthesized and characterized by elemental analysis, spectroscopy (FT-IR, Mass, UV–Vis, photoluminescence, 1H, 13C and 119Sn NMR) and thermogravimetric analysis. Complexes 1 and 4 have also been characterized by single-crystal diffraction studies and the bulk purity established by powder X-ray diffraction studies. Photophysical studies were conducted in a variety of solvents to demonstrate the effect on excitation and emission on the polarity of the solvent. All the new complexes show higher luminescence in a polar solvent resulting in the stabilization of the excited states. Complex 1 shows a high quantum yield of 97% in chloroform. Further, the photophysical results were substantiated through DFT calculations. [Display omitted] [ABSTRACT FROM AUTHOR]