Synthesis, spectral, structural, photoluminescence, thermal and DFT studies of phenylmercury(II) and Ni(II) complexes of 3-methoxycarbonyl-piperidine-1-carbodithioate

Two new complexes [PhHg(mpc)] (1) and [Ni(mpc)(2)] (2) (mpc = 3-methoxycarbonyl-piperidine-1-carbodithioate) have been synthesized and characterized by elemental analyses, IR, NMR, UV-Vis and single crystal X-ray diffraction data. Both the complexes crystallize in triclinic system with space group Pi. The geometry around the Hg(II) ion bonded with phenyl carbon and dithiosulfur atom of mpc is almost linear. Complex 2 is square planar having two unit of mpc ligand. Potassium salt of mpc and complex 1 emit violet light upon excitation at about 293 nm, while complex 2 emit blue light upon excitation at 323 nm wavelength. Cyclic voltammetry studies of free ligand (Kmpc) and its complexes 1 and 2 shows irreversible redox behaviour. Thermal behaviour of the complexes 1 and 2 have been studied which indicate that complex 1 evaporates completely over 700 degrees C temperature where as complex 2 converts into nickel sulfide as final residue. Frontier molecular orbital analysis reveals that complex 2 is softer and more reactive than complex 1. In the solid state, crystal structures of complexes are stabilized by intermolecular interactions. (C) 2018 Elsevier Ltd. All rights reserved.