Abstract: The preparation, X-ray structure characterization and magnetic properties are presented for a new mixed-valence tetranuclear manganese complex that functions as a single-molecule magnet(SMM), [Mn₄(CF₃COO)₄(hmp)₆], where hmp- is the anion of 2-(hydroxymethyl) pyridine and is a N,O bidentate chelate. The compound crystallizes in the monoclinic system, space group P21/c(No.14) with unit cell parameters a=1.3663(3) nm, b=1.4705(3) nm, c=1.4734(3) nm, β=98.51(3)°, V=2.9276 nm³ and Z=2. The structure of the complex shows a novel coordination of the trifluoroacetate(TFA) anions, with one anion acting as a monodentate ligand while the second one coordinating through both oxygens to the same Mn centre. Direct current magnetic susceptibility measurement in the 2—300 K temperature range supports a high-spin ground state. The presence of a frequencey-dependent alternating current susceptibility signal indicates that the individual molecule is acting as the magnet.

Key words: Single-molecule magnet, Manganese complex, Synthesis, Crystal structure, Magnetic property