Octanuclear manganese(II,III) clusters stabilized with diamino-alcoxo ligands

The employment of the 1,3-bis(dimethylamino)-2-propanolate (bdmap) ligand as a chelating/bridging ligand in manganese chemistry is described. The reaction of Mn(R-BzO)₂ and bdmap affords [Mn₈(O)₄(R-BzO)₁₂(bdmap)₂(H₂O)₂], R = H (1), R = 3-Cl (2) and R = 4-Cl (3), which are mixed-valence Mn^II₂Mn^III₆ clusters. Structural characterization was achieved for 1 and 2, which can be described as a central double defective dicubane Mn^III₄ subunit, capped by two oxo-bridged Mn^II-μ(bdmap)-Mn^III dinuclear units. DC variable-temperature magnetic susceptibility studies were carried out in the 2–300 K range, revealing an overall antiferromagnetic behaviour for 1–3. This work demonstrates for the first time the ability of this kind of polytopic ligands in high nuclearity manganese chemistry.