1 H NMR and spectroscopic studies of biologically active yttrium (III)-flavonoid complexes

Abstract

The compounds, Y(L1–5)₃, [where L1–5 = quercetin (L1), morin (L2), naringenin (L3), catechin (L4) and chrysin (L5)] were prepared and characterized by elemental analysis, molar conductance, UV–Vis, thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and proton nuclear magnetic resonance ( ¹H NMR) spectroscopic studies. Molar conductance showed that the complexes are non-electrolytic in nature. The complexes were anhydrous as revealed by the TGA analyses. The ¹H NMR spectra in DMSO-d₆ revealed a diamagnetic shift. The small chemical shift of the proton resonances suggested that the complexes are dissociated in DMSO solvent and the solvent is coordinated to the Y atoms.