From a mononuclear Ni(II) precursor to antiferromagnetically coupled trinuclear double-stranded helicates.

Reaction of the mononuclear Ni(II) complex [Ni{2-Py(6-NH2)NHC(S)NP(S)(OiPr)2}2] with different salicylaldehydes leads to new antiferromagnetically coupled trinuclear double-stranded helicates , where Ni(II) metal ions are coordinated by two bis-anionic thiourea ligands and two deprotonated molecules of the corresponding aldehyde.