Abstract
The preparation, X-ray structure and magnetic properties are presented for a new mixed-valence tetra-nuclear 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 a monoclinic system, space group P21/C (No. 14) with unit cell parameters a = 13.663(3) (A), b = 14.705(3) (A), c = 14.734(3) (A), β = 98.51(3)°, V= 2927.6 (A)3 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 center. Direct current magnetic susceptibility measurement in the 2-300 K temperature range supports a high-spin ground state. The presence of a frequency-dependent alternating current susceptibility signal indicates that the individual molecule is acting as magnet.
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