Synthesis,spectroscopic characterization and X-ray single crystal structures of trans-bis[4-methoxyphenyl (3-methylbutyl) dithiophosphinato] nickel(II) and bis [4-methoxyphenyl (3-methylbutyl) dithiophosphinato]cobalt(II) complexes

Thionation of 3-methylbutylmagnesium bromide with Lawesson’s Reagent (LR) gave 4-methoxyphenyl (3-methylbutyl)dithiophosphinic acid (DTPA), and the latter was converted to the ammonium salt (NH₄L = Ammonium 4-methoxyphenyl (3-methylbutyl) dithiophosphinate). The complex, trans–bis4-methoxyphenyl(3–methylbutyl) dithiophosphinato] nickel(II) NiL₂], was prepared by the reaction of NH₄L with NiCl₂.6H₂O in EtOH. Bis 4-methoxyphenyl (3-methylbutyl) dithiophosphinato]cobalt(II) (CoL₂)₂] was also prepared in the same way. The structures of the complexes have been characterized by elemental analysis, FTIR, ¹H, ¹³C, ³¹P NMR and X-ray diffraction. The single crystal X-ray structures of NiL₂] and (CoL₂)₂] show that the nickel complex is square planar while the cobalt counterpart has tetrahedral coordination with a dimeric structure. Bond lengths, angles, torsion angles and dihedral angles are correlated to the structures and also compared with the literature data on similar compounds.