Preparation of Novel Materials Using SMMs

Magnetic hysteresis is considered a distinctive feature of bulk magnetic materials, where it arises from long-range ordering and irreversible motion of domain walls. However, many anisotropic high-spin molecules, referred to as Single-Molecule Magnets (SMMs), display a hysteresis loop at low temperature and have the potential of being used as molecular-scale units for information storage. This work reviews recent advances in the realization of new bulk materials and low-dimensional nanostructures based on SMMs. Particular reference will be made to mixed-valence Mn12 complexes, which comprise the most versatile and best-performing SMMs available to date. Nonetheless, the described criteria for structure tailoring as well as the guiding principles in material design are of general value and applicability. Examples are given of multifunctional materials of either inorganic or hybrid nature which combine in a unique fashion the magnetic properties of embedded SMMs with the conductive, optical and mechanical characteristics of a polymeric host. In the framework of the molecular approach to electronics, successful attempts to organize SMMs into bidimensional arrays on surfaces and to address them individually have been reported. Recent results in this area will be treated exemplarily, with emphasis on molecular design and surface functionalization. The construction of molecular-scale electronic devices embodying SMMs as active components is finally highlighted among the future developments of this lively research area, which straddles the interface between chemistry and physics.