A Nano Nickel (II) Metal–Organic Coordination Compound for Nano Nickel (II) Oxide: Sonochemical Synthesis and Characterization

A sonochemical method was used to synthesize a nickel (II) coordination complex, [Ni(phen)₃](BF₄)₂·H₂O}_n (1) (phen = 1,10-phenamthroline), with particle sizes in the range of 40–120 nm. The new nanostructure was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (PXRD), infrared, and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction, and the data show that the Ni(II) ions are coordinated by six N-donor atoms from three phen ligands. The charge was balanced by two tetrafluoroborate anions. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. They are further extended into a three-dimensional (3-D) supramolecular structure by weak π–π directional intermolecular interactions. Cubic NiO nanoparticles with sizes of 5–40 nm were obtained by thermolysis of 1 at 180 °C.