Synthesis, crystal structure, Hirshfeld surface analysis and characterization of two new mononuclear Ni(II) complexes.

Two new mononuclear Nickel(II) Schiff base complexes [NiL2] (1) and [NiL2(DMSO)2] (2) where HL is 2,4dibromo-6-[(E)-{[2-(thiophen-2-yl)ethyl]imino}methyl]phenol, a bidentate Schiff base prepared from the condensation reaction of 2-thiopheneethylamine and 3,5dibromosalicylaldehyde, have been made. Complexes 12 are characterized by FTIR, UV-Vis. absorption spectra, TGA analysis (for 2), and single -crystal X-ray diffraction studies. Complexes 1-2 crystallize in a similar space group P21/c as a monoclinic system. X-ray crystallography data indicate that complex 1 has a distorted square planar geometry whereas 2 has distorted octahedral geometry. Using the crystallographic data, the Hirshfeld surface (HS) analysis was also carried out to examine the nature and quantitative contribution of all potential non -covalent intermolecular interactions inside the crystal lattice. Supramolecular chains in 1 through Br center dot center dot center dot Br and ;center dot center dot center dot; interactions and in 2 via C-Br center dot center dot center dot; intermolecular interactions have been observed. The interaction energies between molecules within the crystals were computed to get idea about molecular packing stabilization.