Synthesis, Structural Studies, and Magnetic Exchange Interactions in Low-Valent Manganese Alkoxide Cubes

Tetranuclear manganese(II) alkoxide complexes were prepared from the reaction of MnCl2, a β-diketone, and lithium alkoxide in alcohol. Single-crystal X-ray diffraction studies revealed the presence of a {Mn4(OR)4}4+ core structure with the metals occupying alternating vertices of a cube. The temperature-dependent magnetic susceptibility data for 1−3 could be satisfactorily reproduced by assuming a spin Hamiltonian of the kind ℋ = J1[S1S4 + S2S3] + J2 [S1S2 + S1S3 + S2S4 + S3S4], with J1 ∼4 cm-1 and J2 ∼0.5 cm-1.