Bidentate pyridinylimine (L1-a and L1-b) and pyridinylmethylamine (L2-a and L2-b) derivatives have recently received attention due to their potential use as chemical reagants that can target metal-associated amyloid-beta (A beta) species and modulate metal-induced A beta aggregation and neurotoxicity in vitro and in living cells. Herein, we report the characterization of these bidentate ligands and their corresponding metal complexes by X-ray crystallography and spectroscopic methods, including UV-Vis spectroscopy (UV-Vis), nuclear magnetic resonance spectroscopy (NMR), and Fourier transform infrared spectroscopy (FT-IR). Our studies presented how the different structural moieties of ligand frameworks (L1-a, L1-b, L2-a, and L2-b), in addition to effects of metal binding, contribute to variations in structure and chemical environments of the ligands and their corresponding metal complexes. (C) 2011 Elsevier B.V. All rights reserved.