Synthesis and characterization of different zinc(II) oxide nano-structures from two new zinc(II)–Quinoxaline coordination polymers

• Two new one-dimensional zinc(II) coordination polymers have been synthesized by slow evaporation method.
• Nano crystalline ZnO have successfully been synthesized via techniques of thermolyses.
• The final product was characterized using XRD and SEM methods.
• The same precursors to prepare ZnO nanostructure with different techniques gave us various morphologies.

Two new zinc(II) coordination polymers, [Zn(Quinoxaline)(NO3)2(H2O)2]n⋅Quinoxaline·H2O (1) and [Zn(Quinoxaline)2(Br)2]n (2), Quinoxaline = Benzopyrazine, have been synthesized and characterized by IR spectroscopy. Compounds 1 and 2 were structurally characterized by single crystal X-ray diffraction and are one-dimensional coordination polymers with coordination environment of octahedral and tetrahedral respectively. Nanostructures of zinc(II) oxide were obtained by thermolyses of compound 1 in oleic acid, calcination of compound 1 at 500 °C under air atmosphere and sol–gel processes. Also, nanopowders of zinc(II) oxide were obtained by calcination of compound 2 at 450 and 550 °C. The nanomaterials were characterized by scanning electron microscopy and X-ray powder diffraction (XRD). The thermal stability of compounds 1 and 2 both their bulk were studied by thermo-gravimetric (TGA) and differential thermal analyses (DTA). This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials.