Microwave-assisted synthesis, characterization, DFT/CAM-B3LYPD3BJ studies, NBO and QTAIM analysis of two new copper(II) complexes with ɑ-aminophosphonates

Abstract

Abstract This study presents the rapid, efficient microwave-assisted synthesis of two novel copper(II) complexes with an α-aminophosphonate ligand. Microwave activation enabled us to avoid organic solvents, hazardous substances, and the extensive purification steps typically required by conventional methods. Additionally, these techniques significantly reduced reaction times. Spectroscopic analyses, including infrared (IR), UV-visible, and X-ray diffraction (XRD), as well as cyclic voltammetry, confirmed the structural characteristics of the synthesized compounds. To gain further insight into the structure and properties of the synthesized complexes, computational analyses were performed at the CAM-B3LYPD3BJ/6-31g(d,p) level of theory. These included Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) analysis. Graphical AbstractDiagram of cyclic chemical synthesis featuring reactants, microwave use, yields, and spectral data graphs.The diagram illustrates the synthesis of a binuclear copper complex from a phosphonate ligand and CuCl2, 4H2O, depicting reactants "7a" and "7b" with structural formulas. A microwave is shown with a duration of 3 minutes for the reaction process, leading to a product complex that includes phosphonate ligands and Cl atoms. Yields are indicated as 75-78%. Two graphs present spectral data: one IR spectrum and one UV-Vis absorption spectrum. Arrows indicate the flow of the reaction cycle, integrating elements and connections throughout the layout.