Molecular approaches to next-generation magnetic materials at the nanoscale

Molecular chemistry can bring many powerful advantages to the study of nanoscale
materials of various kinds, and this area of molecular nanoscience is therefore a rapidly
growing field. The advantages include monodisperse (single-size) products and a monolayer
shell of organic ligation that imparts solubility and growth of molecular crystals, allowing
structural characterization to atomic resolution by single-crystal X-ray crystallography. The
ligands can usually also be modified as desired, allowing tuning of redox properties and
atom/isotope labelling (e.g. 2 H, 19 F, etc.) for various studies in solution and the solid state,
such as NMR spectroscopy.
One recent area of interest in our group that has greatly benefitted from the above
advantages is the synthesis and study of molecular clusters that represent a bottom-up
molecular approach to ultra-small nanoparticles of important magnetic and non-magnetic
metal oxides, for example, iron oxide and Ce or Bi oxide. We call such materials ‘molecular
nanoparticles’, as long as their core structure is the same as that of the bulk solid they
represent. With this program now providing a foundation of new materials, it has been
extended to include systems where other magnetic ions and/or single-molecule magnets are
attached to the surface, thus providing a molecular analogue of magnetic units on a metal
oxide support. This talk will describe the synthesis and structures of this class of new
molecular metal oxide systems, together with an analysis of their magnetic properties by a
variety of physical and spectroscopic methods.