THE PREPARATION OF HIGH-NUCLEARITY Pb-Mn MOLECULAR CLUSTERS

Elly Earlywine, Khalil A. Abboud, and George Christou

Department of Chemistry, University of Florida, Gainesville FL 32611-7200, USA

Intense research activity continues in the development of high-nuclearity metallic clusters because of their relevance in the fields of chemistry, physics, and materials science. In our group, the use of manganese, with its various stable paramagnetic oxidation states (II-IV), in metal-oxo-carboxylate chemistry has led to many clusters with fascinating structural features and intriguing magnetic properties. Although great effort has been made in the development of heterometallic manganese clusters, few clusters reported contain manganese and a heavy main group element, such as lead. Several of these heterometallic complexes are of low-nuclearity (six or fewer metal centers), yet show their own interesting physical properties, such as ferroelectricity. Hence, we have initiated a study into the preparation of high-nuclearity Pb-Mn-oxo clusters. We herein present the syntheses, structural analyses and magnetic studies for two new structural topologies: Mn₁₄Pb and Mn₆Pb₅. This work suggests  that additional fascinating heterometallic Pb-Mn-oxo clusters may be obtainable in the future, as well as the possibility of such clusters serving as molecular analogs of bulk  mixed-metal oxide materials.