Synthesis of a tertiary amine by direct reductive amination of a carbonyl compound to form a scorpionate ligand; formation of Mn (II), Zn (II) and Cd (II) complexes, DFT calculations and, molecular docking studies

Abstract

A hexadentate, asymmetric tripodal scorpionate type ligand, [[N1-Pyridin-2-ylmethyl-N1-[2-(4-pyridine-2-ylmethyl-piperazine-1-yl)-ethyl]-ethane-1,2-diamine]] (L) has been prepared. To form this ligand, the direct reductive amination of a carbonyl compound by NaBH4 was used for the synthesis of tertiary amine. The complexes [MnL])ClO4(2, [CdL])ClO4(2, [ZnL])ClO4(2 have also been prepared. The synthesized compounds were characterized by elemental analyses, FT-IR, ESI-MS and, NMR spectroscopy. An X-ray crystal structure of [MnL] (ClO4)2, shows that the coordination environment around the manganese is a distorted trigonal prism. The nature of metal–ligand bonding in the complexes was investigated by Natural Bond Orbital analysis, Energy Decomposition Analysis and Energy Decomposition Analysis using Natural Orbitals for Chemical Valence variation. Molecular docking has been used for the biological evaluation of the anticancer and antioxidant activities of the synthesized compounds. The docking results indicated that the Cd, Mn, and Zn-complexes had the highest binding affinity (MolDock Score) for the binding sites of cytochrome P450, myeloperoxidase, and cytochrome P450, respectively.