Synthesis, crystal structure, DFT and Hirshfeld surface analysis of Ni(II) complexes: Precursor for nickel sulfide nanoparticles

•Four Ni(II) complexes containing dithiocarbamate and triphenylphosphine were prepared.•Complexes were characterized by IR, UV-vis, NMR and single crystal X-ray diffraction.•Nickel sulfide nanoparticles was prepared from a Ni(II) complex.•Catalytic activity of nanoparticles was evaluated for the degradation of rhodamine-6G. Homoleptic complexes, [Ni(iprbpedtc)2] (1) and [Ni(fbtfdtc)2](2) were prepared. Furthermore, 1 and 2 were used as synthon to prepare heteroleptic complexes, [Ni(iprbpedtc)(NCS)(PPh3)] (3) and [Ni(fbtfdtc)(NCS)(PPh3)](4) (where iprbpedtc is N-(4-isopropylbenzyl)-N-(2-phenylethyl)dithiocarbamate and fbtfdtc is N-(4-fluorobenzyl)-N-((tetrahydrofuran-2-yl)methyl)dithiocarbamate). The resulting complexes were characterized by elemental analysis, Fourier transform infrared, NMR (1H and 13C) and electronic spectroscopic techniques. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction and show that the dithiocarbamate ligands are coordinated to the nickel atom in the bidentate manner and the central atom is four coordinated. Hirshfeld surface analysis 1, 3 and 4 reveal that H…H interactions are the largest contribution in the molecular packing. In addition, the structures of 1, 3 and 4 were analyzed with DFT-based approaches. The analysis of the electrophilicity index indicates that complex 4 has the greater electrophilic character compared to those of 1 and 3. The catalytic activity of nanoparticles was evaluated for the degradation of rhodamine-6G dye. Complex 2 was used as a precursor for the preparation of nickel sulfide nanoparticles. Its morphology, structure and optical properties were evaluated using powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and UV-Vis diffuse reflectance spectroscopy. PXRD study shows that the as-prepared nanoparticles consist of β-NiS and α-Ni22.52S19.44. EDS analysis confirms the formation nickel sulfide. [Display omitted] .