Nanoscopic magnetic materials are of increasing interest because of their potential use for ultrahigh – density information storage, quantum computing, sensing and biomedical applications. Among the various types of nanoscopic magnetic materials, single molecule magnets (SMMs) represent a family of promising, for use in the above mentioned technological applications, molecule – based magnetic materials. SMMs are molecular transition-metal clusters that retain their magnetization below a blocking temperature (TB or Tcritical) in the absence of an applied field. In order to employ molecule-based materials in technological applications it is important to prepare SMMs with larger thermodynamic barriers (U) and effective (kinetic) barriers (Ueff) to magnetization reversal and the synthesis of polynuclear heterometallic Mn/lanthanide (Ln) species seems an attractive approach for achieving this. The main idea behind this approach is to combine Mnn+ and Ln3+ ion’s significant spin and/or their large anisotropy to generate Mn/4f SMMs distinctly different from, and superior to, the homometallic ones. The specific scientific and technological objectives of this project include: 1) the preparation of new Mn-Ln-L (L = diol-type ligands) clusters and SMMs, 2) the development of new synthetic procedures to polynuclear Mn-Ln clusters and SMMs, and 3) the complete structural and magnetic characterization of the compounds. The complete magnetic and structural characterization of the compounds is essential in order to rationalize their magnetic properties on the basis of their structural characteristics and finally to achieve optimization of their SMM properties by performing controlled structural modifications.