Two new 1D zigzag Hg(II) nanostructure coordination polymers: Sonochemical synthesis, thermal study, crystal structure and Hirshfeld surface analysis

Reaction of mercury(II) chloride and bromide with a Schiff base ligand based on isonicotinohydrazide (L) yielded two new 1D zigzag coordination polymers; [Hg(mu-L)Cl-2](n) (1) and [Hg(mu-L)Br-2](n) (2). The Schiff base ligand and its Hg(II) complexes have been characterized by FT-IR, UV-Vis, H-1 and C-13 NMR spectroscopy. The structures of the complexes were determined by single crystal X-ray diffraction. Structural data show that the two new mercury complexes have similar structures. In both complexes, Hg(II) ion is five-coordinated by three atoms of Schiff base ligand and two halide anions. The ligand (L) acts as N2O-donor and connects neighboring Hg ion centers to form infinite 1D zigzag chain. This 1D chain is stabilized as 3D supramolecular network by intermolecular interactions of pi center dot center dot center dot pi stacking and X-H center dot center dot center dot Cl (X = N and C) in 1 and C-H center dot center dot center dot pi, pi center dot center dot center dot pi stacking and X-H center dot center dot center dot Br (X = N and C) in 2. Hirshfeld surface analysis and 2D fingerprint plots of asymmetric units of two complexes indicated differences and similarities between crystal packing of compounds. TG/DTG analyses show that compounds 1 and 2 decompose completely during three or four thermal steps, respectively. Nanostructure forms of the titled coordination polymers have been also synthesized by sonochemical method and confirmed by X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). (C) 2016 Elsevier B.V. All rights reserved.