Synthesis and structural characterization of tetra- and pentanuclear lanthanide hydroxido clusters

Abstract

Tetra- and pentanuclear lanthanide clusters having dibenzoylmethanido and o-nitrophenolato as ligands in the coordination sphere were prepared. Treating [LnCl3·6H2O] (Ln = Er, Tm) with dibenzoylmethane and o-nitrophenol in the presence of Methylamine yielded the pentanuclear lanthanide clusters HNEt3+[Ln5(μ 3-OH)4(μ4-OH)(Ph2acac) 7(o-O2NC6H4O)3Cl] - (Ln = Er, Tm). Under the same reaction conditions but using Yb and Lu as center metals, tetranuclear lanthanide clusters [Ln4(μ 3-OH)2(Ph2acac)8(o-O 2NC6H4O)2] (Ln = Yb, Lu) were obtained. The structures of all new compounds were confirmed by single-crystal X-ray diffraction. The anions of the pentanuclear lanthanide cores are square pyramidal. Each triangular face of the square pyramid is capped by one μ3-O moiety. In the square base, four lanthanide atoms are linked by one μ4-O atom. The formation of the hydroxido bridges can be explained by deprotonation of the coordinated water molecules. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007.