Site-specific ligand variation in manganese–oxide cubane complexes, and unusual magnetic relaxation effects in [Mn ₄ O ₄ X(OAc) ₃ (dbm) ₃ ](X = N ₃ – , OCN – Hdbm = dibenzoylmethane)

Treatment of [Mr4O2(OAc)6(py)2(dbm)2]1(py = pyridine, Hdbm = dibenzoylmethane) in hot MeCN with Me3SiX (X = N3–, OCN –) yields [Mn4O3X(OAc)3(dbm)3] containing extremely rare η1, µ3-N3– or -OCN– groups; alternating-current magnetic susceptibility studies reveal unusual magnetic relaxation effects and indicate these species to be the newest and smallest examples yet of truly molecular magnets.