UC San Diego

A series of progressively larger molecules assembled from oxo-centered Mn₃III triangles is presented. All reported complexes have been characterized by bulk magnetic susceptibility and X-ray diffraction. A series of three "single decker" trigonal bipyrimidal [Mn₂IIMn₃III]⁺¹³ single-molecule magnets (SMMs) is reported. The complexes have the general formula of [NEt₄]₃[Mn₅(R-salox)₃O(N₃)₆X₂] where R = H, Me, or Et; and X⁻ = Cl⁻ or Br⁻. The complexes consist of an oxime stabilized [mu]₃-O²⁻ Mn³III triangular core capped with two azide bridged MnII ions. Complexes were synthesized using oxime ligands with increasingly larger alkyl groups pendent to the oximate carbon. Crystal packing of these alkyl groups induced structural distortions which have marked effects on crystal packing, molecular symmetry, and magnetic exchange interactions Structural distortions were induced by crystal packing effects in two "double decker" complexes of the formula [X]₂[Mn₈(salox)₆O₂(N₃)₆(MeOH)₂Cl₂] · 2S, where X⁺ is either NPr₄+С or NBu₄+С and S is either MeOH or CHCl₃, which resulted in changes in magnetic behavior. A third compound that is an antiferromagnetic one dimensional chain magnet constructed from Mn₈ units bridged by N³⁻ ions is described. Two larger compounds are also reported, one comprised of four interconnected oxo-centered Mn₃III triangles. The other is a magnetic 3D metal-organic framework (MOF) synthesized using a modified salicylaldoxime. The complex has the formula [Mn₁₃Na₉O₄(EtO-salox)₁₂(N₃)₆(MeOH)₆(H₂O)₁₀Cl₃][alpha] where EtO-salox is 3-ethoxysalicylaldoxime. The MOF exhibited gas adsorption behavior in addition to magnetic data suggestive of a negative D. Finally, a salicylaldehyde functionalized fullerene has been synthesized and characterized through NMR and mass spectrometry