The new aza–thioether crowns [15]ane(phen N₂)S₃ and [19]ane(phen N₂)S₄ have been synthesised. Their complexation with nickel(II) salts afforded a range of octahedral complexes. The single crystal structures of [Ni{[15]ane(phen N₂)S₃}(NCMe)][BF₄]₂, [NiCl{[15]ane(phen N₂)S₃}]BF₄·dmf (dmf = dimethylformamide) and [NiI{[15]ane(phen N₂)S₃}][I₃] have been determined and confirm N₂S₃ donation of the aza–thioether crown in a folded conformation to Ni^II with the sixth co-ordination site taken up by MeCN, Cl^– and I^– respectively. The complex [Ni₂Cl₂{[19]ane(phen N₂)S₄}₂][BF₄]₂·3MeNO₂ shows a dichlorobridged binuclear structure with the aza–thioether crown bound via only two S- and two N-donors, with two thioether S-donors unbound. A dichloro-bridged binuclear structure was found also for [Ni₂Cl₂{[12]ane(py N)S₃}₂][BF₄]₂·1.5MeNO₂. The redox properties of [Ni{[15]ane(phen N₂)S₃}(NCMe)][BF₄]₂ in MeCN have been examined.