Cyanide-bridged assemblies constructed from capped tetracyanometalate building blocks [M _A(ligand)(CN) ₄] ^1-/2- (M _A=Fe or Cr)

The design and synthesis of cyanide-bridged heterometallic molecular assemblies via self-assembly of capped tetracyanometalate [M _A(L)(CN) ₄] ^n- (M _A=Fe ^III/II, Cr ^III, L=bidentate ligand, n=1, 2) and metal ions in the presence or absence of blocking ligands lead to a wide diversity of structures, ranging from di-, tri-, tetra-, hexanuclear compounds, to various one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) metal-cyanide architectures. Intensive research in this field resulted in the crystallographic and magnetochemical characterization of these metal-cyanide assemblies. The magnetic properties will be discussed in terms of the magnetic exchange coupling between M _A and metal ions. Among these assemblies, ferromagnetically coupled 2,4-ribbon like chains which exhibit slow magnetic relaxation and hysteresis effects are the most appealing single-chain magnets (SCMs).