Synthesis, characterization and photoluminescence of substituted terpyridine compounds and their molecular docking studies with bovine hemoglobin

Reactions between hydroxyl substituted 4'-phenyl-terpyridine ligands p-hydroxyl-4'-phenyl-terpyridine (L-1), m-hydroxyl-4'-phenyl-Terpyridine (L-2) and o-hydroxyl-4'-phenyl-terpyridine (L-3) and ZnCl2 led to the formation of the complexes [Zn(Cl)(2)L-1] (1), [Zn(Cl)(2)L-2] (2) and [Zn(Cl)(2)L-3] (3), respectively, which were characterized by IR, H-1 NMR,C-13 NMR, elemental analysis and single crystal X-ray diffraction, along with their photoluminescent properties. The bindings of the compounds with bovine hemoglobin (BHb) were measured by spectroscopic and molecular docking methods Fluorescence study at the room temperature indicated that the fluorescent intensity of BHb was reduced upon the addition of the compounds by the static quenching mechanism. Based on the results of molecular docking, it could be suggested that the binding process of the compounds with BHb is a spontaneous molecular interaction, in which van der Waals' forces and hydrogen bonds play major roles. The binding constants for the interactions of the compounds with BHb and the numbers of binding sites were also determined. (C) 2018 Elsevier B.V. All rights reserved.