A new family of heterometallic [Cu6M4] (M = Gd, Tb, Dy and Y) clusters derived from the combined use of selected pyridyl poly-alcohol ligands

The combined use of 2-(2-pyridyl)-1,3-propane-diol (pypdH(2)) and 2-hydroxymethyl-2-(2-pyridyl)-1,3-propane-diol (pyptH(3)) in Cu2+/4f chemistry has afforded a new family of isostructural [Cu6M4(pypt)(4)(pypdH)(4)(NO3)(8)] [M = Gd (1), Tb (2), Dy (3), and Y (4)] complexes. These compounds are based on an unprecedented three-layered symmetric [Cu6M4(mu-OR)(16)](8+) structural core, formed from the connection of the metal ions by bridging alkoxide arms of the organic ligands. Direct current magnetic susceptibility studies for complexes 1-3 revealed the presence of dominant ferromagnetic exchange interactions, suggesting the existence of large spin ground state values. Alternating current magnetic studies indicate the presence of slow-magnetic relaxation in 1-3.