Synthesis and characterization of nano-scale of a new azido Co(II) complex as single and nano-scale crystals: Bithiazole precursor for the preparation of Co3O4 nano-structures

Nano-scale and single crystals of a new azido Co(II) complex, {[Co(DADMBTZ)2(N3)2]⋅0.25CH3OH} (1), {DADMBTZ = 2,2′-diamino-5,5′-dimethyl-4,4′-bithiazole} have been synthesized by the reaction of cobalt chloride, sodium azide and DADMBTZ using sonochemical and heat gradient methods, respectively. The new nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and FT-IR spectroscopy. Complex (1) was structurally characterized by single crystal X-ray diffraction. The coordination number of cobalt atom in the compound is six with coordinated environments of distorted octahedral, CoN6. In reaction with DADMBTZ, the ligand DADMBTZ acts as bidentate in complex to form five-membered chelate rings with different internal angles in coordination polyhedron. Two monodentate azido ions occupy the cis position. The crystal packing is mainly stabilized by NH⋯N hydrogen bonding interactions. The thermal stability of compound (1) was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Co3O4 nanostructures were obtained by direct thermolyses of compound (1) at 450 °C under air atmosphere. The Co3O4 nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy.

► 2,2′-diamino-5,5′-dimethyl-4,4′-bithiazole (DADMBTZ) is a new and good ligand.
► The ligand DADMBTZ acts as bidentate in complex to form five-membered chelate rings with different internal angles.
► The crystal packing is mainly stabilized by NH⋯N hydrogen bonding interactions.
► Co3O4 nanostructures were obtained by direct thermolyses of compound at 450 °C under air atmosphere.
► Synthesis of nano-scale bithiazole complex making use of this method is a novel approach in the literature.