Synthesis of mononuclear Ni(II) and binuclear Cu(II) complexes from pyridine-2, crystal structure and Hirschfeld surface analysis, 6-dicarboxylic acid with monothenolamine and hydrochloric acid solution

Two novel complexes, [Ni(dipic)₂](mea)₂(1) and [(dipic)(Cl)(μ-Cl)Cu₂(μ-Cl)(Cl)(dipic)](H₂O) (2), were prepared from mixed ligand in which pyridine-2,6-dicarboxylic acid (PDC or dipicolinic acid, dipic) has reacted with monoethanolamine (MEA) and also hydrochloric acid, respectively. In the complex-1, the dipic ligand containing ONO' donating atoms acted as a monodentate and for complex-2, it was recognized as a neutral state, and both complexes were crystallized in the triclinic space group P ī. The structure of the two complexes was assigned based on elemental and spectroscopic analysis, and also X-ray crystallographic techniques, and finally, the Ni(II) complex confirmed distorted octahedral, and each of the binuclear Cu(II) complexes was also recognized as having the same structure. Hirshfeld surface analysis (HSA) was studied for both complexes as well. According to the analysis report, it expressed the significant intermolecular interactions in packing, with O••H/H••O interactions being the largest (50.9%) for complex-1 and Cl••H/H••Cl interactions (30.1%) followed by H••O/O •••H Interactions (29.8%) of complex-2.