Coordination Polymer of CuI Incorporating a Bidentate Schiff Base Ligand: Synthesis, SC-XRD, HSA, DFT Calculations, and Molecular Docking Studies

Abstract

In this study, we report the synthesis of a novel polymeric Cu(I) complex, [Cu(L4CN)I]n, derived from a Salentype Schiff base ligand, L4CN = 4,4 '-(ethane-1,2-diylbis(azanylylidene))bis(methanylylidene)dibenzonitrile. Single-crystal X-ray diffraction confirmed a binuclear copper(I) structure with a one-dimensional (1D) polymeric architecture. Both Cu centers adopt distorted tetrahedral geometries: Cu-1 is coordinated by two imine nitrogen atoms and two iodide ions, while Cu-2 is coordinated by one cyano nitrogen and three symmetry-related iodide ions. Hirshfeld surface analysis was performed to investigate intra- and intermolecular interactions within and between polymer chains. Density functional theory (DFT) calculations using the B3LYP functional with the Def2TZVP basis set were used to optimize geometries and analyze molecular electrostatic potential (MEP) surfaces. Natural bond orbital (NBO) calculations provided deeper insight into the electronic structure and bonding nature of the complex. Molecular docking studies were conducted using AutoDock Vina to explore binding interactions with deoxyribonucleic acid (DNA) and bovine serum albumin (BSA). The optimized structures of L4CN and [Cu (L4CN)I]n were docked into active sites of DNA and BSA to predict binding affinities, hydrogen bonding, and other non-covalent interactions. The resulting diagrams highlight the spatial orientation of key amino acid residues and nucleotides involved in binding. These computational and experimental findings collectively contribute to understanding the structure-property relationships, stability, and biological interaction potential of Cu(I) coordination polymers for prospective biochemical or therapeutic applications.