Complexes of nickel(II) perchlorate with polymethylenebis(phenylthiourea) ligands

Abstract

The behaviour of polymethylenebis(phenylthiourea) compounds as ligands (L) towards nickel(II) perchlorate has been investigated. The ligand PhHN·CS·NH·CH₂·CH(Me)·NH·CS·NHPh, (I), gives a five-co-ordinate species of chromophore NiS₄O; PhHN·CS·NH·[CH₂]_n·NH·CS·NHPh (III–X; n= 3–10) give insoluble complexes [NiL₃(ClO₄)₂](n= 3–9) with octahedral stereochemistry and a soluble complex [NiL₃(ClO₄)₂](n= 3) that dissociates in solution to give square-planar [NiL₂]²⁺ species (where L is a bidentate ligand). An excess of L gives rise to formation of [NiL₄]²⁺ species, still square planar in stereochemistry, in which the ligand is unidentate. The ligand (X; n= 10) also gives rise to square-planar [NiL₄]²⁺ species in solution but excess of ligand tends to form [NiL₆]²⁺ species having an octahedral NiS₆chromophore.