Structure and characterization of [Pt(Me2pipdt)2][Pt(mnt)2]2 and its inusual magnetic properties

For electro-oxidation of [Pt(Me2pipdt)2][Pt(mnt)2] (Me2pipdtN,N′-dimethyl-piperazine-2,3-dithione; mnt = maleonitrile-2,3-dithiolate) (1a) the novel salt [Pt(Me2pipdt)2][Pt(mnt)2]2 (2a) has been prepared and characterised. 2a exhibits segregated chains of anionic and cationic complexes. The anions generate a non-regular stack with the separation between the planes. The cations are perpendicular to the anions and interposed between those stacks in a ribbon fashion. Magnetic measurements show the presence of a magnetic transition between the behaviour of an antiferromagnetic alternating-exchange chain and the behaviour of a set of antiferromagnetic dimers.