Crystal structure of NH4[Ni{S2C2(CN)2}2]·H2O, the first equidistant stack d7 monoanion metal dithiolene complex

Abstract

The X-ray crystal structure of NH₄[Ni{S₂C₂(CN)₂}₂]·H₂O has revealed that the planar [Ni{S₂C₂(CN)₂}₂]^– anions form an eclipsed equidistant stack structure with a repeat distance of 3.918(8)Å. At 98 K the repeat distance in the stack direction is double that at room temperature indicating that the anions are now associated as dimers. The room-temperature structure and low-temperature transition are related to the unusual magnetic properties of this compound.