In-situ synthesis of dinuclear Iron (III) complex; Crystal structure, DFT calculations, Hirshfield surface analysis, and molecular docking

Abstract

A one-pot reaction of 2-pyridincarboxyaldehyde, 2-amino-1,3-propandiol, FeCl3 and NaN3 in MeOH leading to an in-situ oxazolidine ligand formation enabled the preparation of a new dimeric complex [Fe2(pdom)2(N3)4 (1), where (pdom)− is (2-(pyridin-2-yl)-4,5-dihydrooxazol-4-yl)methanol (pdomH) ligand. Complex 1 was characterised by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction. The structural analysis indicates that 1 is a centrosymmetic molecule where two Fe (III) are bridged by two (pdom)− ligands. The theoretical study of 1 was carried out to assess the structural properties of the complex where the non-covalent interactions and the data indicate good agreement between the theoretical and experimental results. From the density functional theory (DFT) calculations, it was determined that complex 1 adopts the triplet state. In order to get an insight into the possible biological activity of the complex, molecular docking of complex 1 was performed with the DNA topoisomerase I (TOP1), and various conformations of 1 bound with TOP1 were analysed in terms of energy, hydrogen-bonding and hydrophobic interaction. NCI analysis has been investigated to shows its bonding nature. The docking study reveals that complex 1 binds proficiently with TOP1 along the major groove of the DNA with a free energy of 11.72 kcal mol−1, and hydrogen bonds, as calculated by Hirshfeld analysis, are responsible for promoting binding with DNA.