Some Complexes Containing Donor Sulphur Atoms.

Complexes of o-aminobenzenethiol have been obtained with divalent chromium, manganese, iron, cobalt, nickel and zinc. In addition, o-aminobenzenethiolcopper(I), bis(o-iminobenzenethiol)-nickel, tris(o---aminobenzenethiol)cobalt(III) and oxobis(o-amino-benzenethiol)vanadium(lV) have been prepared. Copper(ll) and iron(III) complexes could not be obtained because the ligand reduces copper(II) and iron(III) salts. The blue compound formed by oxidation of bis(o-aminoben-zenethiol)nickel(II) in sodium hydroxide has been shown to be bis(o-iminobenzenethiol)nickel and not an oxygen-bridged nickel(IV) compound as suggested by earlier workers. The dark blue substance which had been claimed to be bis(o-aminobenzenethiol)cobalt(Il) has now been shown to be a mixture of tris(o---aminobenzenethiol)---cobalt(III) and a cobalt oxide, peroxide or hydroxide species. However, it has not been possible to establish the exact nature of this species. The true cobalt(Il) complex is orange-brown and high-spin, not low-spin as was previously thought. Bis(o-amino-benzenethiol)iron(II) is antiferromagnetic with a Neel point at 138°K and an exchange coupling constant of 22.2cm[-1]. It is probable that sulphur bridging is present in many of the o-aminobenzenethiol complexes with divalent metals thereby producing six-coordinate polymeric structures. o-Aminobenzenethiol produces a slightly stronger ligand field than water. Although pure chromium(II) - thiourea complexes could not be obtained, compounds analysing approximately as dichlorobis(thiourea)chromium(II) and hexakis(thiourea)-chromium(II) perchlorate were prepared. In both compounds the thiourea is coordinated through sulphur, and in the chloride antiferromagnetic behaviour suggests either a chlorine- or sulphur-bridged structure. Bis(diethyldithiocar-bamate)chromium(II) has been prepared, but attempts to prepare bis(2-aminoethanethiol)chromium(II) and bis(ethyl xanthate)chromium(II) were unsuccessful