In this research, nano-structure and single crystals(bulk)of, [Co(dipic)2Ni(OH2)5].2H2O where dipic is pyridine - 2,6-dicarboxylic acid, was synthesized usingthe reaction of cobalt (II) nitrate hexahydrate, nickel (II) nitrate hexahydrate, NaOH andpyridine-2,6-dicarboxylic using sonochemical process and reflux approach respectively. The nano-structured of complex was characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and FT-IR spectroscopy and compared with bulk of this complex. The crystal structure(bulk) of this complex, which was synthesized using a reflux approach, was found to be a binuclear coordination complex and was determined using single-crystal X-ray diffraction. The cobalt center in Co(dipic)2 -2achieves hexacoordination by coordinating with two deprotonated dipicolinate groups, which acting as tridentate chelating ligands. In this structure Ni(OH2)5(O)+2part is formed by a hexacoordinated Ni center with five water ligands and one μ- carboxylate oxygen O from the Co(dipic)2 -2 part. Pure phase NiCo2O4 nanoparticles were obtained by thermal decomposition of nano-sized complex at 500 °C under air atmosphere.