Complexes of Zn(II) and Cd(II) with 2-acetylpyridine -aminoguanidine – Syntheses, structures and DFT calculations

Abstract

© 2018 Elsevier B.V. The reaction of 2-acetylpyridine-aminoguanidine dihydrogenchloride (L·2HCl) with Zn(II) and Cd(II) ions, in the presence of deprotonating agent (LiOAc) and without it, yielded two types of complexes, i.e. neutral [Zn(L)Cl2]·H2O and [Cd(L)Cl2] and anionic complexes [H2L][ZnCl4]·H2O and [H2L]2[Cd2Cl8(H2O)2], respectively. In the latter two compounds, 2-acetylpyridine-aminoguanidine does not coordinate the metal and has the role of counter ion. Complexes are characterized by elemental analysis, IR spectroscopy, conductometric measurements and single crystal X-ray analysis. In the neutral complexes, chelating ligand is coordinated in an expected tridentate N3coordination mode via pyridine, azomethine, and nitrogen atom of the imino group of the aminoguanidine residue. Density functional theory (DFT) calculations have been used in order to investigate local reactivity properties of the newly synthesized complexes. Charge transfer within molecule as a consequence of light absorption has been investigated employing the time dependent DFT calculations and formalism of natural transition orbitals. DFT calculations have been also used in order to evaluate fundamental optoelectronic properties.