Nickel(II) complexes of dithiocarbimates from sulfonamides: syntheses and crystal structures

Abstract

This work describes the syntheses of four compounds containing [Ni(RSO 2NCS 2) 2] 2− anions: (Bu 4N) 2[Ni(C 6H 5SO 2NCS 2) 2] ( 1), (Bu 4N) 2[Ni(4-ClC 6H 4SO 2NCS 2) 2] ( 2), (Bu 4N) 2[Ni(2-CH 3C 6H 4SO 2NCS 2) 2] ( 3) and (Bu 4N) 2[Ni(4-BrC 6H 4SO 2NCS 2) 2] ( 4). They were obtained in the crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO 2NCS 2K 2) with nickel(II) chloride hexahydrate in methanol/water. Elemental analyses were consistent with the proposed formulae. UV–Vis and IR data are consistent with the formation of nickel–sulfur diamagnetic planar complexes. The 1H NMR and 13C NMR spectra showed the expected signals for the tetra- n-butylammonium cation and the dithiocarbimate moieties. Single crystal structure analyses showed that (Bu 4N) 2[Ni(2-CH 3C 6H 4SO 2NCS 2) 2] crystallizes in the triclinic space group P 1 ̄ , and (Bu 4N) 2[Ni(4-BrC 6H 4SO 2NCS 2) 2] crystallizes in the monoclinic space group P2 1/ c. In these compounds the Ni atom is coordinated to four S atoms in a distorted square plane geometry. The Ni and S atoms form a plane and NiS bonds are different from each other. In both compounds the Ni atoms are in the crystallographic center of symmetry.