Cd(II) and Ni(II) complexes from aroyl hydrazones: Unravelling the intermolecular interactions and electronic, crystal structures through experimental and theoretical studies

Coordination versatility and structural/electronic properties of three novel Cd(II), Ni(II) complexes from aroyl hydrazones are discussed using experimental and theoretical calculations. [Display omitted] •Three novel Cd(II), Ni(II) complexes from aroyl hydrazones are discussed.•Structural/electronic properties are probed using experimental & theoretical studies.•Hirshfeld, 2D finger print and ESP plots analyses are done.•One of the complex exhibits unusually high dipole moment.•Comparison of frontier orbitals and AIM charge analysis is done by DFT calculations. Three complexes of Cd(II) 1, 2 and Ni(II), 3 were prepared from two different aroyl hydrozone ligands (HL1 (C15H13N3O4) & HL2 (C20H17N3O2)) using their respective metal bromides. Crystal structures of all the three complexes have been established and the anionic/neutral nature of the coordinating ligand is mainly dictated by the nature of the metal center used. Quantification of intermolecular interactions is done using Hirshfeld surface and 2D finger print analysis. The Electrostatic Potential (ESP) analysis reveals that 2 has a collective concentration of negative electrostatic potentials to one side of the molecule giving a perfect separation of charges. DFT/semiempirical calculations revealed the same, giving a very high dipole moment for the optimized geometry of 2. Analysis of frontier orbitals is done through DFT calculations at the B3LYP/def2-TZVP level of theory and atomic charge distributions are predicted using AIM method.