A series of alkali metal salts of bis(2,3-pyrazineditiolate) nickel complexes were synthesized. In these complexes, the Ni(pdt)2 units were arranged in one-dimensional stacks. The stacking motifs and resultant physical properties were quite different depending on the alkali metal cations, which are coordinated by the N atoms of the pdt ligands. Lithium salts showed alternating stacks of monomeric and dimeric Ni(pdt)2 moieties. Potassium and cesium salts showed one-dimensional stacks of monomeric and dimeric Ni(pdt)2 moieties, respectively. Sodium salt showed phase transition between monomeric and dimeric structures at around 220 K. The difference in physical properties was reasonably explained by the crystal structures.
- Phase transition