New derivatives of an enneanuclear Mn SMM

The reaction of the neutral triangular species [Mn3O(O2CR)6L3] (R = Me, Ph, CMe3; L = py) with the tripodal ligands H3tmp (1, 1, 1-tris(hydroxymethyl)propane) and H4peol (pentaerythritol) affords the enneanuclear complexes [Mn9O7(O2CMe)11(tmp)(py)3(H2O)2] (2); [Mn9O7(O2CMe)11(Hpeol)(py)3(H2O)2] (3); [Mn9O7(O2CCMe3)11(Hpeol)(py)3(H2O)2] (4); and [Mn9O7(O2CPh)11(Hpeol)(py)3(H2O)2] (5). Complexes 2–5 are characterized by spin ground states of S = 17/2 with axial zero-field splitting parameters in the range D = −0.26–0.30 cm−1. Sweep-rate and temperature dependent hysteresis loops diagnostic of SMM behaviour are observed below 1.2 K featuring steps at regular intervals of field.

The syntheses, structures and magnetic properties of a family of Mn9 SMMs are discussed.Figure optionsDownload as PowerPoint slide