This thesis presents the synthesis and characterization of two new families of mononuclear complexes, [Fe(L)2(NCS)2] and [Fe(L)(H2B(pz)2)2] showing bistable properties. The crystallographic studies allowed us to discuss the influence of the elongation of the ligands L on the crystal lattice, intermolecular contacts and the existence of structure / properties correlations. The final part of this work shows the controlled synthesis of spin crossover objects at the nanometric scale as thin films prepared by sublimation and nanoclusters synthesized in confined media.
