Synthesis, characterization and magnetic properties of [Mn30O24(OH)(8)(O2CCH2C(CH3)(3))(32)(H2O)(2)(CH3NO2)(4)]: the largest manganese carboxylate cluster

We report the synthesis, structure and magnetic properties of a new member of the family of high nuclearity Mn clusters. The complex [Mn30O24(OH)(8)(O 2CCH2C(CH3)(3))(32)(H2O)(2)(CH3NO2)(4)] (1), is the highest nuclearity mang anese duster to date. Complex 1 was obtained from the comproportionation re action between Mn(OAc)(2). 4H(2)O and KMnO4, followed by ligand substitutio n with Me3CCH2CO2H. It is mixed-valent with a trapped-valence 3Mn(II), 26Mn (III), Mn-IV oxidation state description. Dc magnetic susceptibility studie s indicate an S = 7 ground state, and ac susceptibility studies show an out -of-phase susceptibility signal below 3 K, indicating complex 1 to display the slow magnetization relaxation diagnostic of a single-molecule magnet. ( C) 2001 Elsevier Science Ltd. All rights reserved.