The current intense interest in polynuclear clusters stems not only from their aesthetically pleasing structures, magnetic interactions, and magnetostructural correlations, but also from the discovery that some function as nanoscale magnetic particles, or single-molecule magnets (SMMs). [1] Below their blocking temperature (T B ), such molecules behave as magnets and exhibit hysteresis in scans of magnetization versus dc field. This behavior results from the combination of a large ground spin state (S) with a large and negative (easy-axis type) magnetoanisotropy. SMMs have several potential applications, including high-density information storage, in which each bit of information is stored as the magnetization orientation of an individual molecule, and quantum computation, in which the molecules can serve as qubits.
Although there are many known species displaying SMM behavior, [1][2][3][4][5] most of which are manganese-carboxylate complexes, [3][4][5] there is a continuing need for new SMMs. One of the most successful synthetic approaches to new polynuclear clusters involves the use of chelating ligands containing alkoxide functions, since these are good bridging groups and, thus, favor the formation of polynuclear products. [4] Recently, we have been investigating the use of 1,3propanediol (H 2 pd) and 2-methyl-1,3-propanediol (H 2 mpd) in manganese-carboxylate chemistry. Herein, we report the syntheses, crystal structures, and magnetic properties of two new 3D coordination polymers based on [Mn 19 Na(m 4 -O) 9 (m 3 -