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

摘要

Three new compounds of formula (Cp*Co-2)[Ni(dmit)(2)] (1), (Cp-2*Mn)[Ni(dmid)(2)] center dot (CH3)(2)CO (2), and (Cp-2*Mn)(2)[Ni(dmid)(2)](2) C6H5 CN (3) have been synthesised, and structurally and magnetically characterised (dmit(2-) = 1,3-dithiol-2-thione-4,5-dithiolato; dmid(2-) = 1,3-dithiol-2-one-4,5-dithiolato). Their structural features and magnetic behaviours are compared with those of (Cp-2*Mn)-[Ni(dmit)(2)] and (Cp-2*Mn)[Ni(dmid)(2)] center dot 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 (Cp-2*Mn)[Ni(dmit)(2)]. The change from acetonitrile to acetone when going from (Cp-2*Mn)[Ni(dmid)(2)] center dot 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 (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. (c) 2006 Elsevier B.V. All rights reserved.