Sulphur-nitrogen chelating agents. X. Metal complexes of the tridentate ligand 2,2'-Dithiodianiline and the quinquedentate a, α,α-[Dithiobis(o-phenylenenitrio)]di-2-picoline

Abstract

Metal complexes of the disulphides 2,2?-dithiodianiline (dta) and α,α- [dithiobis-(o-phenylenenitrilo)]di-2-picoline (dtpp) have been investigated. In the complexes Ni(dta)X₂ (X = Cl, Br) the ligand is coordinated by one sulphur and two nitrogen atoms. In the complexes [M(dtpp)X]X, nH₂O (M = Mn, Ni; X = Cl, Br), [Ni(dtpp)Cl]-ClO₄, [Ni(dtpp)X] BF₄ (X = Cl, Br), and [Mn(dtpp)I] ClO₄ the disulphide dtpp acts as a quinquedentate, being bound by one sulphur and four nitrogen atoms. The compound [Ni(dtpp)Br] Br,H₂O was obtained by reaction of Ni(dta)Br₂ with pyridine-2-carbaldehyde.    Under certain conditions dtpp is reduced in the presence of nickel ions to give complexes of 2-(2?-pyridylmethylene)aminobenzenethiol (pabtH). Two complexes of empirical formula Ni(pabt)Cl were isolated: the reddish-brown, diamagnetic square-planar complex Ni(pabt)Cl and a green paramagnetic complex Ni(pabt)₂,NiCl₂ which may have a thio-bridged structure.