Crystal structures and magnetic properties of Ni-bisdithiolene complexes with decamethylmetallocenium cations

Three new compounds of formula View the MathML source(Cp2∗Co)[Ni(dmit)2](1), View the MathML source(Cp2∗Mn)[Ni(dmid)2]·(CH3)2CO (2), and View the MathML source(Cp2∗Mn)2[Ni(dmid)2]2·C6H5CN (3) have been synthesised, and structurally and magnetically characterised (dmit2− = 1,3-dithiol-2-thione-4,5-dithiolato; dmid2− = 1,3-dithiol-2-one-4,5-dithiolato). Their structural features and magnetic behaviours are compared with those of View the MathML source(Cp2∗Mn)[Ni(dmit)2] and View the MathML source(Cp2∗Mn)[Ni(dmid)2]·CH3CN. The result of this is that the interactions between the Ni(dmit)2 units in 1 are of ferromagnetic-type, as suggested previously for View the MathML source(Cp2∗Mn)[Ni(dmit)2]. The change from acetonitrile to acetone when going from View the MathML source(Cp2∗Mn)[Ni(dmid)2]·CH3CN to 2 results in stronger ferromagnetic intermolecular interactions. This better cooperativity is due to a significant increase of the number of contacts between the various moieties within the View the MathML source(Cp2∗Mn)[Ni(dmid)2]·solvent. On the contrary, the inclusion of larger solvents such as benzonitrile in this type of complexes results in a totally different structural arrangement, which leads to an antiferromagnetic behaviour for 3.