Crystal structure and Hirshfeld surface analysis of copper(II) β-aminovinyl ketone complexes

The results of the synthesis and investigation of two copper(II) complexes based on 1-phenyl-3-(8-quinolylamino)but-2-en-1-one (HL) are presented. Both complexes were characterized by elemental analysis and IR spectroscopy. The crystalline and molecular structure of copper(II) complexes was determined using single-crystal X-ray diffraction analysis. Depending on the synthesis method (with or without the addition of sodium methoxide in a methanol solution), two different types of crystal structures with compositions CuL₂ and CuLCOOCH₃ were obtained. The Hirschfeld surface analysis method was used to analyze interactions between molecules in crystals, which made it possible to visualize and quantify hydrogen bonds, van der Waals forces, and π-π stacking interactions in these compounds. This study demonstrated that the structure of the complex is dependent on the synthesis conditions that affect the coordination environment of copper(II) ions and the characteristics of intermolecular interaction.