Magnetization dynamics in single-molecule magnets

The synthesis and physical characterization of several polynuclear transition metal complexes are reported. In some cases, these complexes are shown to be single-molecule magnets. The magnetic properties of these complexes are examined in great detail.; Results are given which describe the synthesis of a family of [Mn 12O12(O2CR)16(H2O) 4] complexes. Some of these complexes have magnetization relaxation dynamics that are significantly faster than some of the other analogously prepared [Mn12] complexes. Single crystal magnetization and high frequency EPR (HFEPR) experiments were performed to characterize the spin ground states of these complexes. It is shown that the magnetization dynamics of some of these [Mn12] complexes are very sensitive to their environment.; Results are given which describe the synthesis of a new family of novel wheel shaped [Mn12] complexes. A ligand system is identified which yields wheel shaped [Fe6] complexes in addition to these [Mn 12] complexes. Each of these [Mn12] wheels is shown to be a SMM. The synthesis and magnetic properties for a family of trinuclear and hexanuclear ferric complexes are also described. Detailed EPR and magnetometry experiments have been carried out to characterize their spin ground states.