Molecular computer technology will benefit from a breakthrough in single molecule magnetism, say Australian researchers. 

Keith Murray and colleagues at Monash University have made magnetic complexes containing two manganese(II) and two manganese(III) cations, bound in butterfly motifs. The manganese(II) ions occupied the body-body positions. Similar complexes with different arrangements of metal ions and ligands have been made before, with the manganese(II) ions in the wing-tip positions.

Murray found the type of bridging ligand and position of the metal ion affected the magnetic behaviour of the complexes; the body-positioned complexes were much less magnetic than their analogues.

Murray's explanation is that the bridging ligands influenced the manganese geometries, the oxidation state distribution and therefore the magnetism levels. Possible fine tuning of these properties could be useful to scientists developing molecular computer technology, said Murray.

The group's discovery of the complexes' magnetic behaviour was serendipitous, but they recognised it to be important for developing novel strongly magnetic complexes, or single molecule magnets (SMMs). Murray now plans to make extended arrays of SMM clusters which he hopes will have potential for use in memory devices like molecular computers. 

Robin James Forder