Capabilities and Limitations of the Spin Hamiltonian Formalism in Single Molecule Magnets

The rational design of molecular magnetic materials is an ongoing effort involving physics, materials science, and chemistry. A common approach to design of complexes and interpretation of magnetic data is the spin Hamiltonian formalism. In this approach, magnetic data is interpreted through constants extracted from the parameterization of data. In design, certain structural motifs are pursued, rationalized by the minimization or maximization of terms in the spin Hamiltonian. In this work, monometallic complexes were prepared to simplify magnetic behavior and allow the examination of specific factors that influence single molecule magnetism like coordination geometry, ligand identity, symmetry, and spin-orbit coupling. A series of hydridotris(3-phenylpyrazolylborato) scorpionate compounds are presented, some of which are inadequately described by the parameterization of magnetic data, and others for which the alteration of terms within the spin Hamiltonian gives the predicted result. These discoveries and ramifications for single molecule magnetism will be discussed. A series of dmf adducts of transition metal para-toluenesulfonates is also presented