Description
Transition-metal nitride containing molecules are of interest for their ability to act as single molecule magnets (SMMs), which are poised to revolutionize data storage and molecular electronics. SMMs are isolated molecules that exhibit superparamagnetic susceptibility below a magnetic blocking temperature. The ability of these molecules to retain magnetization in the absence of a magnetic field depends on a potential energy barrier for reversal of their aligned electron spins, denoted by the equation U = DS², where D is a measure of the axial zero-field splitting in the molecule and S is the spin ground state. In order for the SMM to be effective it is necessary to have a high negative D and a high S value. Despite their potential to act as SMMs, examples of molecules containing the nitride anion bound to paramagnetic, transition-metal ions are scarce in literature. This is likely due to the dearth of facile synthetic methods to attain them. In pursuing convenient precursors to these molecules, three complexes, [Cl₃Mn·N(SnMe₃)₃]¹⁻, [Cl₃Co·N(SnMe₃)₃]¹⁻, and [Br₃Co·N(SnMe₃)₃]¹⁻, have been isolated. These complexes have the potential to behave as SMMs because of the anisotropy in the coordination of the central metal ions. Additionally, these complexes are promising thermolytic precursors to high-nuclearity nitride containing molecules and materials. In polynuclear molecules, a high spin ground state can be achieved by long-range electron exchange coupling between the metals of the molecule through the coordinated ligands. A new salt of the previously studied trinuclear transition-metal anion [Co₃(THF)₂Cl₈]²⁻ has been synthesized with a simple alkyl ammonium cation. The magnetic properties of this complex were not formerly probed, but interesting behavior likely due to the nature of the linear configuration of the cobalt ions has been observed. Furthermore, two inorganic polymer complexes with formulas [Co₅Cl₁₀(THF)₆][subscript n] and [Mn₉Cl₁₉(THF)₁₄][subscript n] have been synthesized. The magnetic properties of the cobalt chain have been investigated because single-chain magnets (SCMs), just as SMMs, retain the ability to exhibit high magnetization relaxation barriers
