Copper(II) complexes with semicarbazones: synthesis, characterization and noncovalent interactions in their crystal structures

The present work reports the synthesis and structural elucidation of six novel copper(II) complexes with 2-acetylpyridine semicarbazone (HL1) and 2-acetylpyridine N(4)-phenyl semicarbazone (HL2). In all compounds, the semicarbazone ligands were find tridentate with NNO-donor atoms. The single crystal X-ray diffraction analysis showed the influences of the different copper salt starting reagent in the crystal structures. A packing architectures analysis has been undertaken to delineate the role of relevant noncovalent interactions. The pi center dot center dot center dot pi stacking interactions and hydrogen bonds were analyzed using the Hirshfeld surface and fingerprint plots. In addition, the compounds were also characterized by physicochemical and spectroscopic methods.