Synthesis and structure of phases containing [Ni3P3S12]3- crown-shaped trimers

The exfoliation process of one-dimensional KNiPS4 showed that the breaking of (1)/(infinity) [NiPS4](-) chains in polar solvent was followed by the formation of cyclic [Ni3P3S12](3-) trianions. From DMF-KNiPS4 solutions, metathesis experiments were successfully carried out, but, up to now, K+ had only been exchanged by bigger isotropic organic cations such as PPh4+, (CH3)(4)N+ and (C2H5)(4)N+. After recrystallization, each metathesis compound presents the cyclic [Ni3P3S12](3-) trianion. An exchange by anisotropic cations is possible by adding a cryptand molecule that fits the size of K+. Following this procedure, three new nickel thiophosphate complexes have been synthesized: [Ni3P3S12] [K-(222-cryptand)](3) (I), [Ni3P3S12][K(222-cryptand)]2[C9N1H22] (II) and [Ni3P3S12][CH3(CH2)(11)N(CH3)(3)](3) ( III). The structures of I and II have been fully determined from single crystal X-ray diffraction analysis. They show the occurrence of the [Ni3P3S12](3-) trimer within the solid. I and II crystallize in the P2(1)2(1)2(1) space group. P-31 solid state NMR experiments hint at the presence of polyanions in III, maybe trianionic in nature.