Synthesis, Spectral Properties, in Vitro α-Glucosidase Inhibitory Activity and Quantum Chemical Calculations of Novel Mixed-Ligand M(II) Complexes Containing 1,10-Phenanthroline

Abstract

A series of mixed-ligand M(II) complexes containing 1,10-phenanthroline (phen) and 3-methylpyridine-2-carboxylic acid (3-mpaH) or 6-methylpyridine-2-carboxylic acid (6-mpaH), namely [Co(3-mpa)<inf>2</inf>(phen)]·3H<inf>2</inf>O (1), [Hg(6-mpa)<inf>2</inf>(phen)]·2H<inf>2</inf>O (2), [Mn(6-mpa)<inf>2</inf>(phen)]·2H<inf>2</inf>O (3), [Co(6-mpa)<inf>2</inf>(phen)]·H<inf>2</inf>O (4) and [Ni(6-mpa)<inf>2</inf>(phen)]·H<inf>2</inf>O (5), were synthesized for the first time. Among them, 1 was obtained as single crystals. The structural characterization for 1 was conducted using X-ray diffraction and that for 2–5 using mass spectrometry. The IC<inf>50</inf> values for α-glucosidase inhibition of 1–5 were obtained as 0.161 to >600 μM. The spectral properties were also investigated using Fourier transform infrared and UV–visible spectra. Furthermore, to investigate the geometrical parameters, spectral and electronic properties and second- and third-order nonlinear optical parameters for 1–5, density functional calculations were applied. © 2020 John Wiley & Sons, Ltd.