Two novel 1D mercury(II) polymeric coordination compounds, namely {[Hg2(L)(Cl)4]·0.5(H2O)}n (1) and [Hg2(L)(Br)4]n (2) (where L = bis(2-pyridylmethyl)-ketazine), C14H15N4) were synthesized using either a branched tube or sonochemical method. The XRD powder spectra confirmed the same crystalline phase for compounds produced by both the methods. Single crystal X-ray analysis of 1 and 2 obtained using the branched tube revealed isomorphous and isostructural structures of 2,2,3C6 topology, comprising penta-coordinated Hg2+ ions. The Hirshfeld surface analysis of the crystal packing of complexes 1 and 2 was discussed in detail to evaluate the interactions among the polymers that are affected by the different halogen atoms present. The effects of experimental conditions utilized for the sonochemical method (power and reaction time) were analyzed with respect to the growth and final morphology of the nanostructures obtained. While reaction time directly affected the final size of the nanostructures of 1 and 2, the sonication power showed an inverse trend. The microcrystals of 1 and 2 thus obtained were further analyzed by IR spectroscopy, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).