Ionothermal Synthesis of Four New Nickel Thiophosphate Anions: [Ni(P2S8)2]2-, [Ni(P3S9)(P2S8)]3-, [Ni(P3S9)2]4-, and [(NiP3S8)4(PS4)]7-

Four new nickel thiophosphate anions have been isolated as 1-ethyl-3-methylimidazolium (EMIM) salts: [EMIM](2)[Ni(P2S8)(2)] (1), [EMIM](3)[Ni(P3S9)(P2S8)] (2), [EMIM](4)[Ni(P3S9)(2)] (3), and [EMIM](7)[(NiP3S8)(4)(PS4)] (4). Single crystals of each were prepared by ionothermal reaction of the elements in [EMIM][BF4]. 1 can also be obtained from [EMIM][CF3SO3]. In all four anions, Ni atoms are octahedrally coordinated and P atoms are tetrahedrally coordinated. In the anion found in 1, two tridentate 1,3-P2S82- ligands are cis to each other. The anion in 2 contains two different tridentate thiophosphate ligands, 1,3-P2S82- and P3S93-, whereas the anion in 3 consists of two P3S93- ligands coordinated to the central Ni atom. The anion in 4 is complex, consisting of four NiP3S8- clusters surrounding a central PS4 tetrahedron; within the NiP3S8- groups, one P atom is directly bound to Ni. The discovery of these four new compounds demonstrates the versatility of ionothermal methods for the synthesis of novel thiophosphates.