Synthesis, crystal structure, DFT calculations, molecular docking study and Hirshfeld surface analysis of alkoxido-bridged dinuclear iron(III) complex

Abstract

Reaction of FeCl2·4H2O, NaN3 and N,N′-bis(2-hydroxyethyl)-ethylenediamine (heenH2) in a CH3CN/CH2Cl2 solution resulted in a dinuclear complex, [Fe2III(heen)2(N3)2] (1). Structural analysis indicates that 1 is a centrosymmetric molecule, and two Fe(III) are bridged by two heen2− ligands. The theoretical study of 1 was carried out to assess the structural properties of the complex and the non-covalent interactions, and the data indicate the much agreement between the experimental and the theoretical results. The triplet state in the electronic system was verified by the comparison of electronic energies gained at the density functional theory level. To get an insight of the possible employment of the present complex in biology, molecular docking was performed, and various conformations of 1 bound with DNA were analyzed in terms of energy, hydrogen-bonding and hydrophobic interaction. The docking study demonstrates that complex binds proficiently with the DNA receptor (in the minor groove) and describes free energy of binding values of − 256.02 kcal mol−1, and hydrogen bonds, as calculated by Hirshfeld analysis, are responsible for promoting binding with DNA. The energetically most favorable conformation of the docked pose showed that complex comes close toward the gap between DNA minor groove by the use of nitrogen of azide and deprotonated oxygen attached to the aliphatic chain of ligand (heenH2). Theoretically, the possible aspects of the Fe(III) complex in structural chemistry and biology in future endeavors have been explored.