Nickel complexes of the methyl esters of dithiocarbazic and N-substituted dithiocarbazic acids

Abstract

The nickel complexes of the methyl esters of dithiocarbazic acid NH₂NHC(=S)SMe (L), 2-methyldithiocarbazic acid NH₂NMeC(=S)SMe (MeL), 2-n-butyldithiocarbazic acid, NH₂NBuC(=S)SMe (BuL), 3,3-dimethyldithiocarbazic acid NMe₂NHC(=S)SMe (Me₂L), 3-phenyldithiocarbazic acid NHPhNHC(=S)SMe (PhL), and 3,3-diphenyldithiocarbazic acid NPh₂NHC(=S)SMe (Ph₂L) have been investigated. L, MeL, BuL, and Me₂L can act as neutral ligands giving the high-spin complexes [NiL₃]X₂, [Ni(MeL)₃]X₂, [Ni(BuL)₃]X₂(X = Cl, Br, or I), and [Ni(Me₂L)₂Cl₂]; L and Me₂L can act also in deprotonated form at N(2) giving the low-spin complexes [Ni(L – H)₂] and [Ni(Me₂ L – H)₂]. PhL and Ph₂L act only in deprotonated form at N(2) giving the low-spin [Ni(PhL – H)₂] and [Ni(Ph₂L – H)₂] respectively. MeL and BuL can be deprotonated at N(3) after co-ordination giving the low-spin complexes [Ni(MeL – H)₂] and [Ni(BuL – H)₂]. The complexes have been characterized by their electronic and i.r. spectra.