A Mn₁₂ single-molecule magnet [Mn₁₂O ₁₂(OAc)₁₂(dpp)₄] (dppH = diphenyl phosphate) with no coordinating water molecules

The preparation and physical characterization are reported for a novel single-molecule magnet [Mn₁₂O₁₂(OAc)₁₂(dpp) ₄] (dppH = diphenyl phosphate) with no coordinating water molecules. The crystal structure analysis reveals that there are four five-coordinate Mn^III ions with Mn⋯H approaches. Addition of water in CD ₂Cl₂ solution was monitored by ¹H NMR, which showed that H₂O could coordinate to a vacant site of a five-coordinate Mn^III ion in solution. The measurements and analyses of magnetization hysteresis and ac magnetic susceptibility indicate that the title complex is a single-molecule magnet with a quantum tunneling behavior, whose ground state was tentatively assigned to S = 10 with g = 1.78 and D = -0.60 K.