Synthesis, crystal structures and characterization of Nickel(II) complexes with dithiobenzoate derivatives

Abstract

New nickel(II) complexes with dithiobenzoate ligands, [NiII(Me-dtb)2] and [NiII(Oct-dtb)2]2 (Me-dtb = 4-methyl-dithiobenzoate and Oct-dtb = 4-octyl-dithiobenzoate), were synthesized and structurally characterized using X–ray diffraction analysis. [NiII(Me-dtb)2] has a mononuclear structure, including a nickel(II) ion with a square planar coordination geometry, and [NiII(Oct-dtb)2]2 has a dinuclear structure connected by weak Ni•••S interactions in the apical position of the nickel ion. The solutions of these complexes show strong light absorption at approximately 600 nm with a dark blue color. To reveal the electronic states and mechanism of the light absorption of Ni(II)- dithiobenzoate complexes, optimization of the ground-state molecular structures and excited-state calculations for [NiII(dtb)2] (dtb = dithiobenzoate) and [NiII(Me2dtc)2] (Me2dtc = dimethyl-dithiocarbamate) were performed by DFT/B3LYP method and TD-DFT/CAM-B3LYP method, respectively.