A theoretical and experimental study on isonitrosoacetophenone nicotinoyl hydrazone: Crystal structure, spectroscopic properties, NBO, NPA and NLMO analyses and the investigation of interaction with some transition metals

Abstract

A new hydrazone oxime compound, isonitrosoacetophenone nicotinoyl hydrazone (inapNH2), was synthesized and characterized by spectroscopic techniques (FT-IR, 1H-NMR and 13C-NMR) and single-crystal X-ray diffraction. The molecular geometry, NMR chemical shift values and vibrational frequencies of the inapNH2 in the ground state have been calculated by using the Density Functional Method (DFT/B3LYP) with 6-31G(d) and 6-311++G(d,p) basis sets. The computational results obtained were in agreement with the experimental results. The thermodynamic parameters of the inapNH2 were calculated at different temperatures, and the changes in thermodynamic properties were studied with increasing temperature. The molecular stability originating from charge transfer and hyperconjugative interactions in the title compound was analyzed using Natural Bond Orbital (NBO) and Natural Localized Molecular Orbital (NLMO) analyzes. The Natural Population Analysis (NPA) charges obtained from NBO analysis were used in order to find out the possible coordination modes of the inapNH2 compound with metal ions. To predict the chemical reactivity of the molecule, the molecular electrostatic potential (MEP) surface map of inapNH2 was investigated and some of its global reactivity descriptors (chemical potential μ, electronegativity χ, hardness η and electrophilicity index ω) were calculated using DFT. Furthermore, the strength of metal–ligand interaction between chlorides of Co(II), Ni(II), Cu(II), Zn(II) and inapNH2, in both aqueous and ethanol phases, was elucidated by using the values of Charge Transfer (ΔN) and Energy Lowering (ΔE). The results indicated that the best interaction in both solvents is between CuCl2 and inapNH2.