Hexanuclear, Heterometallic, Ni<sub>3</sub>Ln<sub>3</sub> Complexes Possessing O‑Capped Homo- and Heterometallic Structural Subunits: SMM Behavior of the Dysprosium Analogue

The reaction of hetero donor chelating mannich base ligand 6,6′-{(2-(dimethylamino)­ethylazanediyl)­bis­(methylene)}­bis­(2-methoxy-4-methylphenol) with Ni­(ClO<sub>4</sub>)<sub>2</sub>·6H<sub>2</sub>O and lanthanide­(III) salts [Dy­(III) (<b>1</b>); Tb­(III) (<b>2</b>); Gd (III) (<b>3</b>); Ho­(III) (<b>4</b>); and Er­(III) (<b>5</b>)] in the presence of triethylamine and pivalic acid afforded a series of heterometallic hexanuclear Ni­(II)–Ln­(III) coordination compounds, [Ni<sub>3</sub>Ln<sub>3</sub>(μ<sub>3</sub>-O)­(μ<sub>3</sub>-OH)<sub>3</sub>(L)<sub>3</sub>­(μ-OOCCMe<sub>3</sub>)<sub>3</sub>]·(ClO<sub>4</sub>)·<i>w</i>CH<sub>3</sub>CN·<i>x</i>CH<sub>2</sub>Cl<sub>2</sub>·<i>y</i>CH<sub>3</sub>OH·<i>z</i>H<sub>2</sub>O [for <b>1</b>, <i>w</i> = 8, <i>x</i> = 3, <i>y</i> = 0, <i>z</i> = 5.5; for <b>2</b>, <i>w</i> = 0, <i>x</i> = 5, <i>y</i> = 0, <i>z</i> = 6.5; for <b>3</b>, <i>w</i> = 15, <i>x</i> = 18, <i>y</i> = 3, <i>z</i> = 7.5; for <b>4</b>, <i>w</i> = 15, <i>x</i> = 20, <i>y</i> = 6, <i>z</i> = 9.5; and for <b>5</b>, <i>w</i> = 0, <i>x</i> = 3, <i>y</i> = 2, <i>z</i> = 3]. The molecular structure of these complexes reveals the presence of a monocationic hexanuclear derivative containing one perchlorate counteranion. The asymmetric unit of each of the hexanuclear derivatives comprises the dinuclear motif [NiLn­(L)­(μ<sub>3</sub>-O)­(μ<sub>3</sub>-OH)­(μ-Piv)]. The cation contains three interlinked O-capped clusters: one Ln<sup>III</sup><sub>3</sub>O and three Ni<sup>II</sup>Ln<sup>III</sup><sub>2</sub>O. Each of the lanthanide centers is eight- coordinated (distorted trigonal-dodecahedron), while the nickel centers are hexacoordinate (distorted octahedral). The study of the magnetic properties of all compounds are reported and suggests single molecule magnet behavior for the Dy­(III) derivative (<b>1</b>).