New derivatives of an enneanuclear MnSMM

The reaction of the neutral triangular species [Mn3O(O2CR)(6)L-3] (R = Me, Ph, CMe3; L = py) with the tripodal ligands H(3)tmp (1, 1, 1-tris(hydroxymethyl)propane) and H(4)peol (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. (c) 2006 Elsevier Ltd. All rights reserved.